提交 34bbea91 编写于 作者: M Mauro Carvalho Chehab

Merge tag 'v4.5-rc1' into patchwork

Linux 4.5-rc1

* tag 'v4.5-rc1': (11309 commits)
  Linux 4.5-rc1
  ideapad-laptop: Add Lenovo Yoga 700 to no_hw_rfkill dmi list
  MAINTAINERS: Combine multiple telemetry entries
  intel_telemetry_debugfs: Fix unused warnings in telemetry debugfs
  vmstat: Remove BUG_ON from vmstat_update
  MIPS: zboot: Add support for serial debug using the PROM
  MIPS: zboot: Avoid useless rebuilds
  MIPS: BMIPS: Enable ARCH_WANT_OPTIONAL_GPIOLIB
  MIPS: bcm63xx: nvram: Remove unused bcm63xx_nvram_get_psi_size() function
  MIPS: bcm963xx: Update bcm_tag field image_sequence
  MIPS: bcm963xx: Move extended flash address to bcm_tag header file
  MIPS: bcm963xx: Move Broadcom BCM963xx image tag data structure
  MIPS: bcm63xx: nvram: Use nvram structure definition from header file
  MIPS: bcm963xx: Add Broadcom BCM963xx board nvram data structure
  MAINTAINERS: Add KVM for MIPS entry
  MIPS: KVM: Add missing newline to kvm_err()
  MIPS: Move KVM specific opcodes into asm/inst.h
  MIPS: KVM: Use cacheops.h definitions
  MIPS: Break down cacheops.h definitions
  MIPS: Use EXCCODE_ constants with set_except_vector()
  ...

要显示的变更太多。

To preserve performance only 1000 of 1000+ files are displayed.
......@@ -534,6 +534,7 @@ N: NeilBrown
E: neil@brown.name
P: 4096R/566281B9 1BC6 29EB D390 D870 7B5F 497A 39EC 9EDD 5662 81B9
D: NFSD Maintainer 2000-2007
D: MD Maintainer 2001-2016
N: Zach Brown
E: zab@zabbo.net
......@@ -1507,6 +1508,14 @@ S: 312/107 Canberra Avenue
S: Griffith, ACT 2603
S: Australia
N: Andreas Herrmann
E: herrmann.der.user@gmail.com
E: herrmann.der.user@googlemail.com
D: Key developer of x86/AMD64
D: Author of AMD family 15h processor power monitoring driver
D: Maintainer of AMD Athlon 64 and Opteron processor frequency driver
S: Germany
N: Sebastian Hetze
E: she@lunetix.de
D: German Linux Documentation,
......@@ -1847,6 +1856,16 @@ S: Korte Heul 95
S: 1403 ND BUSSUM
S: The Netherlands
N: Martin Kepplinger
E: martink@posteo.de
E: martin.kepplinger@theobroma-systems.com
W: http://www.martinkepplinger.com
D: mma8452 accelerators iio driver
D: Kernel cleanups
S: Garnisonstraße 26
S: 4020 Linz
S: Austria
N: Karl Keyte
E: karl@koft.com
D: Disk usage statistics and modifications to line printer driver
......
What: /config/iio
Date: October 2015
KernelVersion: 4.4
Contact: linux-iio@vger.kernel.org
Description:
This represents Industrial IO configuration entry point
directory. It contains sub-groups corresponding to IIO
objects.
What: /config/iio/triggers
Date: October 2015
KernelVersion: 4.4
Description:
Industrial IO software triggers directory.
What: /config/iio/triggers/hrtimers
Date: October 2015
KernelVersion: 4.4
Description:
High resolution timers directory. Creating a directory here
will result in creating a hrtimer trigger in the IIO subsystem.
What: /config/rdma_cm
Date: November 29, 2015
KernelVersion: 4.4.0
Description: Interface is used to configure RDMA-cable HCAs in respect to
RDMA-CM attributes.
Attributes are visible only when configfs is mounted. To mount
configfs in /config directory use:
# mount -t configfs none /config/
In order to set parameters related to a specific HCA, a directory
for this HCA has to be created:
mkdir -p /config/rdma_cm/<hca>
What: /config/rdma_cm/<hca>/ports/<port-num>/default_roce_mode
Date: November 29, 2015
KernelVersion: 4.4.0
Description: RDMA-CM based connections from HCA <hca> at port <port-num>
will be initiated with this RoCE type as default.
The possible RoCE types are either "IB/RoCE v1" or "RoCE v2".
This parameter has RW access.
......@@ -10,3 +10,5 @@ Description:
isoc_mult - 0..2 (hs/ss only)
isoc_maxburst - 0..15 (ss only)
buflen - buffer length
bulk_qlen - depth of queue for bulk
iso_qlen - depth of queue for iso
What: /config/usb-gadget/gadget/functions/tcm.name
Date: Dec 2015
KernelVersion: 4.5
Description:
There are no attributes because all the configuration
is performed in the "target" subsystem of configfs.
What: /sys/bus/iio/devices/iio:deviceX/in_allow_async_readout
Date: December 2015
KernelVersion: 4.4
Contact: linux-iio@vger.kernel.org
Description:
By default (value '0'), the capture thread checks for the Conversion
Ready Flag to being set prior to committing a new value to the sample
buffer. This synchronizes the in-chip conversion rate with the
in-driver readout rate at the cost of an additional register read.
Writing '1' will remove the polling for the Conversion Ready Flags to
save the additional i2c transaction, which will improve the bandwidth
available for reading data. However, samples can be occasionally skipped
or repeated, depending on the beat between the capture and conversion
rates.
What: /sys/bus/iio/devices/iio:deviceX/in_shunt_resistor
Date: December 2015
KernelVersion: 4.4
Contact: linux-iio@vger.kernel.org
Description:
The value of the shunt resistor may be known only at runtime fom an
eeprom content read by a client application. This attribute allows to
set its value in ohms.
......@@ -134,19 +134,21 @@ Description:
enabled for the device. Developer can write y/Y/1 or n/N/0 to
the file to enable/disable the feature.
What: /sys/bus/usb/devices/.../power/usb3_hardware_lpm
Date: June 2015
What: /sys/bus/usb/devices/.../power/usb3_hardware_lpm_u1
/sys/bus/usb/devices/.../power/usb3_hardware_lpm_u2
Date: November 2015
Contact: Kevin Strasser <kevin.strasser@linux.intel.com>
Lu Baolu <baolu.lu@linux.intel.com>
Description:
If CONFIG_PM is set and a USB 3.0 lpm-capable device is plugged
in to a xHCI host which supports link PM, it will check if U1
and U2 exit latencies have been set in the BOS descriptor; if
the check is is passed and the host supports USB3 hardware LPM,
the check is passed and the host supports USB3 hardware LPM,
USB3 hardware LPM will be enabled for the device and the USB
device directory will contain a file named
power/usb3_hardware_lpm. The file holds a string value (enable
or disable) indicating whether or not USB3 hardware LPM is
enabled for the device.
device directory will contain two files named
power/usb3_hardware_lpm_u1 and power/usb3_hardware_lpm_u2. These
files hold a string value (enable or disable) indicating whether
or not USB3 hardware LPM U1 or U2 is enabled for the device.
What: /sys/bus/usb/devices/.../removable
Date: February 2012
......@@ -187,6 +189,17 @@ Description:
The file will read "hotplug", "wired" and "not used" if the
information is available, and "unknown" otherwise.
What: /sys/bus/usb/devices/.../(hub interface)/portX/usb3_lpm_permit
Date: November 2015
Contact: Lu Baolu <baolu.lu@linux.intel.com>
Description:
Some USB3.0 devices are not friendly to USB3 LPM. usb3_lpm_permit
attribute allows enabling/disabling usb3 lpm of a port. It takes
effect both before and after a usb device is enumerated. Supported
values are "0" if both u1 and u2 are NOT permitted, "u1" if only u1
is permitted, "u2" if only u2 is permitted, "u1_u2" if both u1 and
u2 are permitted.
What: /sys/bus/usb/devices/.../power/usb2_lpm_l1_timeout
Date: May 2013
Contact: Mathias Nyman <mathias.nyman@linux.intel.com>
......
What: /sys/class/infiniband/<hca>/ports/<port-number>/gid_attrs/ndevs/<gid-index>
Date: November 29, 2015
KernelVersion: 4.4.0
Contact: linux-rdma@vger.kernel.org
Description: The net-device's name associated with the GID resides
at index <gid-index>.
What: /sys/class/infiniband/<hca>/ports/<port-number>/gid_attrs/types/<gid-index>
Date: November 29, 2015
KernelVersion: 4.4.0
Contact: linux-rdma@vger.kernel.org
Description: The RoCE type of the associated GID resides at index <gid-index>.
This could either be "IB/RoCE v1" for IB and RoCE v1 based GODs
or "RoCE v2" for RoCE v2 based GIDs.
......@@ -19,6 +19,25 @@ Description:
Set to 0 to pad all frames. Set greater than tx_max to
disable all padding.
What: /sys/class/net/<iface>/cdc_ncm/ndp_to_end
Date: Dec 2015
KernelVersion: 4.5
Contact: Bjørn Mork <bjorn@mork.no>
Description:
Boolean attribute showing the status of the "NDP to
end" quirk. Defaults to 'N', except for devices
already known to need it enabled.
The "NDP to end" quirk makes the driver place the NDP
(the packet index table) after the payload. The NCM
specification does not mandate this, but some devices
are known to be more restrictive. Write 'Y' to this
attribute for temporary testing of a suspect device
failing to work with the default driver settings.
A device entry should be added to the driver if this
quirk is found to be required.
What: /sys/class/net/<iface>/cdc_ncm/rx_max
Date: May 2014
KernelVersion: 3.16
......
......@@ -8,7 +8,7 @@ Description:
What: /sys/class/net/<mesh_iface>/mesh/<vlan_subdir>/ap_isolation
Date: May 2011
Contact: Antonio Quartulli <antonio@meshcoding.com>
Contact: Antonio Quartulli <a@unstable.cc>
Description:
Indicates whether the data traffic going from a
wireless client to another wireless client will be
......@@ -70,7 +70,7 @@ Description:
What: /sys/class/net/<mesh_iface>/mesh/isolation_mark
Date: Nov 2013
Contact: Antonio Quartulli <antonio@meshcoding.com>
Contact: Antonio Quartulli <a@unstable.cc>
Description:
Defines the isolation mark (and its bitmask) which
is used to classify clients as "isolated" by the
......
What: /sys/class/net/<iface>/qmi/raw_ip
Date: Dec 2015
KernelVersion: 4.4
Contact: Bjørn Mork <bjorn@mork.no>
Description:
Boolean. Default: 'N'
Set this to 'Y' to change the network device link
framing from '802.3' to 'raw-ip'.
The netdev will change to reflect the link framing
mode. The netdev is an ordinary ethernet device in
'802.3' mode, and the driver expects to exchange
frames with an ethernet header over the USB link. The
netdev is a headerless p-t-p device in 'raw-ip' mode,
and the driver expects to echange IPv4 or IPv6 packets
without any L2 header over the USB link.
Userspace is in full control of firmware configuration
through the delegation of the QMI protocol. Userspace
is responsible for coordination of driver and firmware
link framing mode, changing this setting to 'Y' if the
firmware is configured for 'raw-ip' mode.
What: /sys/class/watchdog/watchdogn/bootstatus
Date: August 2015
Contact: Wim Van Sebroeck <wim@iguana.be>
Description:
It is a read only file. It contains status of the watchdog
device at boot. It is equivalent to WDIOC_GETBOOTSTATUS of
ioctl interface.
What: /sys/class/watchdog/watchdogn/identity
Date: August 2015
Contact: Wim Van Sebroeck <wim@iguana.be>
Description:
It is a read only file. It contains identity string of
watchdog device.
What: /sys/class/watchdog/watchdogn/nowayout
Date: August 2015
Contact: Wim Van Sebroeck <wim@iguana.be>
Description:
It is a read only file. While reading, it gives '1' if that
device supports nowayout feature else, it gives '0'.
What: /sys/class/watchdog/watchdogn/state
Date: August 2015
Contact: Wim Van Sebroeck <wim@iguana.be>
Description:
It is a read only file. It gives active/inactive status of
watchdog device.
What: /sys/class/watchdog/watchdogn/status
Date: August 2015
Contact: Wim Van Sebroeck <wim@iguana.be>
Description:
It is a read only file. It contains watchdog device's
internal status bits. It is equivalent to WDIOC_GETSTATUS
of ioctl interface.
What: /sys/class/watchdog/watchdogn/timeleft
Date: August 2015
Contact: Wim Van Sebroeck <wim@iguana.be>
Description:
It is a read only file. It contains value of time left for
reset generation. It is equivalent to WDIOC_GETTIMELEFT of
ioctl interface.
What: /sys/class/watchdog/watchdogn/timeout
Date: August 2015
Contact: Wim Van Sebroeck <wim@iguana.be>
Description:
It is a read only file. It is read to know about current
value of timeout programmed.
......@@ -87,6 +87,12 @@ Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
Description:
Controls the checkpoint timing.
What: /sys/fs/f2fs/<disk>/idle_interval
Date: January 2016
Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
Description:
Controls the idle timing.
What: /sys/fs/f2fs/<disk>/ra_nid_pages
Date: October 2015
Contact: "Chao Yu" <chao2.yu@samsung.com>
......
......@@ -33,7 +33,7 @@ Description:
The object directory contains subdirectories for each function
that is patched within the object.
What: /sys/kernel/livepatch/<patch>/<object>/<function>
What: /sys/kernel/livepatch/<patch>/<object>/<function,sympos>
Date: Nov 2014
KernelVersion: 3.19.0
Contact: live-patching@vger.kernel.org
......@@ -41,4 +41,8 @@ Description:
The function directory contains attributes regarding the
properties and state of the patched function.
The directory name contains the patched function name and a
sympos number corresponding to the nth occurrence of the symbol
name in kallsyms for the patched object.
There are currently no such attributes.
......@@ -74,7 +74,7 @@ Description:
assignment may be changed by two writing numbers into
the file.
What: /sys/class/ptp/ptpN/pps_avaiable
What: /sys/class/ptp/ptpN/pps_available
Date: September 2010
Contact: Richard Cochran <richardcochran@gmail.com>
Description:
......
......@@ -430,7 +430,7 @@ The rationale for using gotos is:
return result;
}
A common type of bug to be aware of it "one err bugs" which look like this:
A common type of bug to be aware of is "one err bugs" which look like this:
err:
kfree(foo->bar);
......
......@@ -951,16 +951,6 @@ to "Closing".
alignment constraints (e.g. the alignment constraints about 64-bit
objects).
3) Supporting multiple types of IOMMUs
If your architecture needs to support multiple types of IOMMUs, you
can use include/linux/asm-generic/dma-mapping-common.h. It's a
library to support the DMA API with multiple types of IOMMUs. Lots
of architectures (x86, powerpc, sh, alpha, ia64, microblaze and
sparc) use it. Choose one to see how it can be used. If you need to
support multiple types of IOMMUs in a single system, the example of
x86 or powerpc helps.
Closing
This document, and the API itself, would not be in its current
......
......@@ -236,7 +236,7 @@ are guaranteed also to be cache line boundaries).
DMA_TO_DEVICE synchronisation must be done after the last modification
of the memory region by the software and before it is handed off to
the driver. Once this primitive is used, memory covered by this
the device. Once this primitive is used, memory covered by this
primitive should be treated as read-only by the device. If the device
may write to it at any point, it should be DMA_BIDIRECTIONAL (see
below).
......
......@@ -50,8 +50,7 @@ pdfdocs: $(PDF)
HTML := $(sort $(patsubst %.xml, %.html, $(BOOKS)))
htmldocs: $(HTML)
$(call build_main_index)
$(call build_images)
$(call cmd,build_main_index)
$(call install_media_images)
MAN := $(patsubst %.xml, %.9, $(BOOKS))
......@@ -139,7 +138,8 @@ quiet_cmd_db2pdf = PDF $@
index = index.html
main_idx = $(obj)/$(index)
build_main_index = rm -rf $(main_idx); \
quiet_cmd_build_main_index = HTML $(main_idx)
cmd_build_main_index = rm -rf $(main_idx); \
echo '<h1>Linux Kernel HTML Documentation</h1>' >> $(main_idx) && \
echo '<h2>Kernel Version: $(KERNELVERSION)</h2>' >> $(main_idx) && \
cat $(HTML) >> $(main_idx)
......@@ -227,6 +227,10 @@ dochelp:
@echo ' mandocs - man pages'
@echo ' installmandocs - install man pages generated by mandocs'
@echo ' cleandocs - clean all generated DocBook files'
@echo
@echo 'make DOCBOOKS="s1.xml s2.xml" [target] Generate only docs s1.xml s2.xml'
@echo ' valid values for DOCBOOKS are: $(DOCBOOKS)'
###
# Temporary files left by various tools
......
......@@ -263,6 +263,7 @@ X!Isound/sound_firmware.c
!Iinclude/media/lirc_dev.h
</sect1>
<sect1><title>Media Controller devices</title>
!Pinclude/media/media-device.h Media Controller
!Iinclude/media/media-device.h
!Iinclude/media/media-devnode.h
!Iinclude/media/media-entity.h
......
此差异已折叠。
......@@ -458,7 +458,7 @@
.scan_type = {
.sign = 's',
.realbits = 12,
.storgebits = 16,
.storagebits = 16,
.shift = 4,
.endianness = IIO_LE,
},
......
......@@ -58,21 +58,36 @@
<title>Media device model</title>
<para>Discovering a device internal topology, and configuring it at runtime,
is one of the goals of the media controller API. To achieve this, hardware
devices are modelled as an oriented graph of building blocks called entities
connected through pads.</para>
<para>An entity is a basic media hardware or software building block. It can
correspond to a large variety of logical blocks such as physical hardware
devices (CMOS sensor for instance), logical hardware devices (a building
block in a System-on-Chip image processing pipeline), DMA channels or
physical connectors.</para>
<para>A pad is a connection endpoint through which an entity can interact
with other entities. Data (not restricted to video) produced by an entity
flows from the entity's output to one or more entity inputs. Pads should not
be confused with physical pins at chip boundaries.</para>
<para>A link is a point-to-point oriented connection between two pads,
either on the same entity or on different entities. Data flows from a source
pad to a sink pad.</para>
devices and Linux Kernel interfaces are modelled as graph objects on
an oriented graph. The object types that constitute the graph are:</para>
<itemizedlist>
<listitem><para>An <emphasis role="bold">entity</emphasis>
is a basic media hardware or software building block. It can correspond to
a large variety of logical blocks such as physical hardware devices
(CMOS sensor for instance), logical hardware devices (a building block in
a System-on-Chip image processing pipeline), DMA channels or physical
connectors.</para></listitem>
<listitem><para>An <emphasis role="bold">interface</emphasis>
is a graph representation of a Linux Kernel userspace API interface,
like a device node or a sysfs file that controls one or more entities
in the graph.</para></listitem>
<listitem><para>A <emphasis role="bold">pad</emphasis>
is a data connection endpoint through which an entity can interact with
other entities. Data (not restricted to video) produced by an entity
flows from the entity's output to one or more entity inputs. Pads should
not be confused with physical pins at chip boundaries.</para></listitem>
<listitem><para>A <emphasis role="bold">data link</emphasis>
is a point-to-point oriented connection between two pads, either on the
same entity or on different entities. Data flows from a source pad to a
sink pad.</para></listitem>
<listitem><para>An <emphasis role="bold">interface link</emphasis>
is a point-to-point bidirectional control connection between a Linux
Kernel interface and an entity.m</para></listitem>
</itemizedlist>
</section>
<!-- All non-ioctl specific data types go here. -->
&sub-media-types;
</chapter>
<appendix id="media-user-func">
......@@ -83,6 +98,7 @@
&sub-media-func-ioctl;
<!-- All ioctls go here. -->
&sub-media-ioc-device-info;
&sub-media-ioc-g-topology;
&sub-media-ioc-enum-entities;
&sub-media-ioc-enum-links;
&sub-media-ioc-setup-link;
......
......@@ -59,15 +59,6 @@
<para>Entity IDs can be non-contiguous. Applications must
<emphasis>not</emphasis> try to enumerate entities by calling
MEDIA_IOC_ENUM_ENTITIES with increasing id's until they get an error.</para>
<para>Two or more entities that share a common non-zero
<structfield>group_id</structfield> value are considered as logically
grouped. Groups are used to report
<itemizedlist>
<listitem><para>ALSA, VBI and video nodes that carry the same media
stream</para></listitem>
<listitem><para>lens and flash controllers associated with a sensor</para></listitem>
</itemizedlist>
</para>
<table pgwide="1" frame="none" id="media-entity-desc">
<title>struct <structname>media_entity_desc</structname></title>
......@@ -106,7 +97,7 @@
<entry><structfield>revision</structfield></entry>
<entry></entry>
<entry></entry>
<entry>Entity revision in a driver/hardware specific format.</entry>
<entry>Entity revision. Always zero (obsolete)</entry>
</row>
<row>
<entry>__u32</entry>
......@@ -120,7 +111,7 @@
<entry><structfield>group_id</structfield></entry>
<entry></entry>
<entry></entry>
<entry>Entity group ID</entry>
<entry>Entity group ID. Always zero (obsolete)</entry>
</row>
<row>
<entry>__u16</entry>
......@@ -171,97 +162,6 @@
</tbody>
</tgroup>
</table>
<table frame="none" pgwide="1" id="media-entity-type">
<title>Media entity types</title>
<tgroup cols="2">
<colspec colname="c1"/>
<colspec colname="c2"/>
<tbody valign="top">
<row>
<entry><constant>MEDIA_ENT_T_DEVNODE</constant></entry>
<entry>Unknown device node</entry>
</row>
<row>
<entry><constant>MEDIA_ENT_T_DEVNODE_V4L</constant></entry>
<entry>V4L video, radio or vbi device node</entry>
</row>
<row>
<entry><constant>MEDIA_ENT_T_DEVNODE_FB</constant></entry>
<entry>Frame buffer device node</entry>
</row>
<row>
<entry><constant>MEDIA_ENT_T_DEVNODE_ALSA</constant></entry>
<entry>ALSA card</entry>
</row>
<row>
<entry><constant>MEDIA_ENT_T_DEVNODE_DVB_FE</constant></entry>
<entry>DVB frontend devnode</entry>
</row>
<row>
<entry><constant>MEDIA_ENT_T_DEVNODE_DVB_DEMUX</constant></entry>
<entry>DVB demux devnode</entry>
</row>
<row>
<entry><constant>MEDIA_ENT_T_DEVNODE_DVB_DVR</constant></entry>
<entry>DVB DVR devnode</entry>
</row>
<row>
<entry><constant>MEDIA_ENT_T_DEVNODE_DVB_CA</constant></entry>
<entry>DVB CAM devnode</entry>
</row>
<row>
<entry><constant>MEDIA_ENT_T_DEVNODE_DVB_NET</constant></entry>
<entry>DVB network devnode</entry>
</row>
<row>
<entry><constant>MEDIA_ENT_T_V4L2_SUBDEV</constant></entry>
<entry>Unknown V4L sub-device</entry>
</row>
<row>
<entry><constant>MEDIA_ENT_T_V4L2_SUBDEV_SENSOR</constant></entry>
<entry>Video sensor</entry>
</row>
<row>
<entry><constant>MEDIA_ENT_T_V4L2_SUBDEV_FLASH</constant></entry>
<entry>Flash controller</entry>
</row>
<row>
<entry><constant>MEDIA_ENT_T_V4L2_SUBDEV_LENS</constant></entry>
<entry>Lens controller</entry>
</row>
<row>
<entry><constant>MEDIA_ENT_T_V4L2_SUBDEV_DECODER</constant></entry>
<entry>Video decoder, the basic function of the video decoder is to
accept analogue video from a wide variety of sources such as
broadcast, DVD players, cameras and video cassette recorders, in
either NTSC, PAL or HD format and still occasionally SECAM, separate
it into its component parts, luminance and chrominance, and output
it in some digital video standard, with appropriate embedded timing
signals.</entry>
</row>
<row>
<entry><constant>MEDIA_ENT_T_V4L2_SUBDEV_TUNER</constant></entry>
<entry>TV and/or radio tuner</entry>
</row>
</tbody>
</tgroup>
</table>
<table frame="none" pgwide="1" id="media-entity-flag">
<title>Media entity flags</title>
<tgroup cols="2">
<colspec colname="c1"/>
<colspec colname="c2"/>
<tbody valign="top">
<row>
<entry><constant>MEDIA_ENT_FL_DEFAULT</constant></entry>
<entry>Default entity for its type. Used to discover the default
audio, VBI and video devices, the default camera sensor, ...</entry>
</row>
</tbody>
</tgroup>
</table>
</refsect1>
<refsect1>
......
......@@ -118,35 +118,6 @@
</tgroup>
</table>
<table frame="none" pgwide="1" id="media-pad-flag">
<title>Media pad flags</title>
<tgroup cols="2">
<colspec colname="c1"/>
<colspec colname="c2"/>
<tbody valign="top">
<row>
<entry><constant>MEDIA_PAD_FL_SINK</constant></entry>
<entry>Input pad, relative to the entity. Input pads sink data and
are targets of links.</entry>
</row>
<row>
<entry><constant>MEDIA_PAD_FL_SOURCE</constant></entry>
<entry>Output pad, relative to the entity. Output pads source data
and are origins of links.</entry>
</row>
<row>
<entry><constant>MEDIA_PAD_FL_MUST_CONNECT</constant></entry>
<entry>If this flag is set and the pad is linked to any other
pad, then at least one of those links must be enabled for the
entity to be able to stream. There could be temporary reasons
(e.g. device configuration dependent) for the pad to need
enabled links even when this flag isn't set; the absence of the
flag doesn't imply there is none.</entry>
</row>
</tbody>
</tgroup>
</table>
<table pgwide="1" frame="none" id="media-link-desc">
<title>struct <structname>media_link_desc</structname></title>
<tgroup cols="3">
......@@ -171,33 +142,6 @@
</tgroup>
</table>
<table frame="none" pgwide="1" id="media-link-flag">
<title>Media link flags</title>
<tgroup cols="2">
<colspec colname="c1"/>
<colspec colname="c2"/>
<tbody valign="top">
<row>
<entry><constant>MEDIA_LNK_FL_ENABLED</constant></entry>
<entry>The link is enabled and can be used to transfer media data.
When two or more links target a sink pad, only one of them can be
enabled at a time.</entry>
</row>
<row>
<entry><constant>MEDIA_LNK_FL_IMMUTABLE</constant></entry>
<entry>The link enabled state can't be modified at runtime. An
immutable link is always enabled.</entry>
</row>
<row>
<entry><constant>MEDIA_LNK_FL_DYNAMIC</constant></entry>
<entry>The link enabled state can be modified during streaming. This
flag is set by drivers and is read-only for applications.</entry>
</row>
</tbody>
</tgroup>
</table>
<para>One and only one of <constant>MEDIA_PAD_FL_SINK</constant> and
<constant>MEDIA_PAD_FL_SOURCE</constant> must be set for every pad.</para>
</refsect1>
<refsect1>
......
<refentry id="media-g-topology">
<refmeta>
<refentrytitle>ioctl MEDIA_IOC_G_TOPOLOGY</refentrytitle>
&manvol;
</refmeta>
<refnamediv>
<refname>MEDIA_IOC_G_TOPOLOGY</refname>
<refpurpose>Enumerate the graph topology and graph element properties</refpurpose>
</refnamediv>
<refsynopsisdiv>
<funcsynopsis>
<funcprototype>
<funcdef>int <function>ioctl</function></funcdef>
<paramdef>int <parameter>fd</parameter></paramdef>
<paramdef>int <parameter>request</parameter></paramdef>
<paramdef>struct media_v2_topology *<parameter>argp</parameter></paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Arguments</title>
<variablelist>
<varlistentry>
<term><parameter>fd</parameter></term>
<listitem>
<para>File descriptor returned by
<link linkend='media-func-open'><function>open()</function></link>.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>request</parameter></term>
<listitem>
<para>MEDIA_IOC_G_TOPOLOGY</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>argp</parameter></term>
<listitem>
<para></para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Description</title>
<para><emphasis role="bold">NOTE:</emphasis> This new ioctl is programmed to be added on Kernel 4.6. Its definition/arguments may change until its final version.</para>
<para>The typical usage of this ioctl is to call it twice.
On the first call, the structure defined at &media-v2-topology; should
be zeroed. At return, if no errors happen, this ioctl will return the
<constant>topology_version</constant> and the total number of entities,
interfaces, pads and links.</para>
<para>Before the second call, the userspace should allocate arrays to
store the graph elements that are desired, putting the pointers to them
at the ptr_entities, ptr_interfaces, ptr_links and/or ptr_pads, keeping
the other values untouched.</para>
<para>If the <constant>topology_version</constant> remains the same, the
ioctl should fill the desired arrays with the media graph elements.</para>
<table pgwide="1" frame="none" id="media-v2-topology">
<title>struct <structname>media_v2_topology</structname></title>
<tgroup cols="5">
<colspec colname="c1" />
<colspec colname="c2" />
<colspec colname="c3" />
<colspec colname="c4" />
<colspec colname="c5" />
<tbody valign="top">
<row>
<entry>__u64</entry>
<entry><structfield>topology_version</structfield></entry>
<entry></entry>
<entry></entry>
<entry>Version of the media graph topology. When the graph is
created, this field starts with zero. Every time a graph
element is added or removed, this field is
incremented.</entry>
</row>
<row>
<entry>__u64</entry>
<entry><structfield>num_entities</structfield></entry>
<entry></entry>
<entry></entry>
<entry>Number of entities in the graph</entry>
</row>
<row>
<entry>__u64</entry>
<entry><structfield>ptr_entities</structfield></entry>
<entry></entry>
<entry></entry>
<entry>A pointer to a memory area where the entities array
will be stored, converted to a 64-bits integer.
It can be zero. if zero, the ioctl won't store the
entities. It will just update
<constant>num_entities</constant></entry>
</row>
<row>
<entry>__u64</entry>
<entry><structfield>num_interfaces</structfield></entry>
<entry></entry>
<entry></entry>
<entry>Number of interfaces in the graph</entry>
</row>
<row>
<entry>__u64</entry>
<entry><structfield>ptr_interfaces</structfield></entry>
<entry></entry>
<entry></entry>
<entry>A pointer to a memory area where the interfaces array
will be stored, converted to a 64-bits integer.
It can be zero. if zero, the ioctl won't store the
interfaces. It will just update
<constant>num_interfaces</constant></entry>
</row>
<row>
<entry>__u64</entry>
<entry><structfield>num_pads</structfield></entry>
<entry></entry>
<entry></entry>
<entry>Total number of pads in the graph</entry>
</row>
<row>
<entry>__u64</entry>
<entry><structfield>ptr_pads</structfield></entry>
<entry></entry>
<entry></entry>
<entry>A pointer to a memory area where the pads array
will be stored, converted to a 64-bits integer.
It can be zero. if zero, the ioctl won't store the
pads. It will just update
<constant>num_pads</constant></entry>
</row>
<row>
<entry>__u64</entry>
<entry><structfield>num_links</structfield></entry>
<entry></entry>
<entry></entry>
<entry>Total number of data and interface links in the graph</entry>
</row>
<row>
<entry>__u64</entry>
<entry><structfield>ptr_links</structfield></entry>
<entry></entry>
<entry></entry>
<entry>A pointer to a memory area where the links array
will be stored, converted to a 64-bits integer.
It can be zero. if zero, the ioctl won't store the
links. It will just update
<constant>num_links</constant></entry>
</row>
</tbody>
</tgroup>
</table>
<table pgwide="1" frame="none" id="media-v2-entity">
<title>struct <structname>media_v2_entity</structname></title>
<tgroup cols="5">
<colspec colname="c1" />
<colspec colname="c2" />
<colspec colname="c3" />
<colspec colname="c4" />
<colspec colname="c5" />
<tbody valign="top">
<row>
<entry>__u32</entry>
<entry><structfield>id</structfield></entry>
<entry></entry>
<entry></entry>
<entry>Unique ID for the entity.</entry>
</row>
<row>
<entry>char</entry>
<entry><structfield>name</structfield>[64]</entry>
<entry></entry>
<entry></entry>
<entry>Entity name as an UTF-8 NULL-terminated string.</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>function</structfield></entry>
<entry></entry>
<entry></entry>
<entry>Entity main function, see <xref linkend="media-entity-type" /> for details.</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>reserved</structfield>[12]</entry>
<entry>Reserved for future extensions. Drivers and applications must
set this array to zero.</entry>
</row>
</tbody>
</tgroup>
</table>
<table pgwide="1" frame="none" id="media-v2-interface">
<title>struct <structname>media_v2_interface</structname></title>
<tgroup cols="5">
<colspec colname="c1" />
<colspec colname="c2" />
<colspec colname="c3" />
<colspec colname="c4" />
<colspec colname="c5" />
<tbody valign="top">
<row>
<entry>__u32</entry>
<entry><structfield>id</structfield></entry>
<entry></entry>
<entry></entry>
<entry>Unique ID for the interface.</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>intf_type</structfield></entry>
<entry></entry>
<entry></entry>
<entry>Interface type, see <xref linkend="media-intf-type" /> for details.</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>flags</structfield></entry>
<entry></entry>
<entry></entry>
<entry>Interface flags. Currently unused.</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>reserved</structfield>[9]</entry>
<entry></entry>
<entry></entry>
<entry>Reserved for future extensions. Drivers and applications must
set this array to zero.</entry>
</row>
<row>
<entry>struct media_v2_intf_devnode</entry>
<entry><structfield>devnode</structfield></entry>
<entry></entry>
<entry></entry>
<entry>Used only for device node interfaces. See <xref linkend="media-v2-intf-devnode" /> for details..</entry>
</row>
</tbody>
</tgroup>
</table>
<table pgwide="1" frame="none" id="media-v2-intf-devnode">
<title>struct <structname>media_v2_interface</structname></title>
<tgroup cols="5">
<colspec colname="c1" />
<colspec colname="c2" />
<colspec colname="c3" />
<colspec colname="c4" />
<colspec colname="c5" />
<tbody valign="top">
<row>
<entry>__u32</entry>
<entry><structfield>major</structfield></entry>
<entry></entry>
<entry></entry>
<entry>Device node major number.</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>minor</structfield></entry>
<entry></entry>
<entry></entry>
<entry>Device node minor number.</entry>
</row>
</tbody>
</tgroup>
</table>
<table pgwide="1" frame="none" id="media-v2-pad">
<title>struct <structname>media_v2_pad</structname></title>
<tgroup cols="5">
<colspec colname="c1" />
<colspec colname="c2" />
<colspec colname="c3" />
<colspec colname="c4" />
<colspec colname="c5" />
<tbody valign="top">
<row>
<entry>__u32</entry>
<entry><structfield>id</structfield></entry>
<entry></entry>
<entry></entry>
<entry>Unique ID for the pad.</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>entity_id</structfield></entry>
<entry></entry>
<entry></entry>
<entry>Unique ID for the entity where this pad belongs.</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>flags</structfield></entry>
<entry></entry>
<entry></entry>
<entry>Pad flags, see <xref linkend="media-pad-flag" /> for more details.</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>reserved</structfield>[9]</entry>
<entry></entry>
<entry></entry>
<entry>Reserved for future extensions. Drivers and applications must
set this array to zero.</entry>
</row>
</tbody>
</tgroup>
</table>
<table pgwide="1" frame="none" id="media-v2-link">
<title>struct <structname>media_v2_pad</structname></title>
<tgroup cols="5">
<colspec colname="c1" />
<colspec colname="c2" />
<colspec colname="c3" />
<colspec colname="c4" />
<colspec colname="c5" />
<tbody valign="top">
<row>
<entry>__u32</entry>
<entry><structfield>id</structfield></entry>
<entry></entry>
<entry></entry>
<entry>Unique ID for the pad.</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>source_id</structfield></entry>
<entry></entry>
<entry></entry>
<entry>
<para>On pad to pad links: unique ID for the source pad.</para>
<para>On interface to entity links: unique ID for the interface.</para>
</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>sink_id</structfield></entry>
<entry></entry>
<entry></entry>
<entry>
<para>On pad to pad links: unique ID for the sink pad.</para>
<para>On interface to entity links: unique ID for the entity.</para>
</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>flags</structfield></entry>
<entry></entry>
<entry></entry>
<entry>Link flags, see <xref linkend="media-link-flag" /> for more details.</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>reserved</structfield>[5]</entry>
<entry></entry>
<entry></entry>
<entry>Reserved for future extensions. Drivers and applications must
set this array to zero.</entry>
</row>
</tbody>
</tgroup>
</table>
</refsect1>
<refsect1>
&return-value;
<variablelist>
<varlistentry>
<term><errorcode>ENOSPC</errorcode></term>
<listitem>
<para>This is returned when either one or more of the num_entities,
num_interfaces, num_links or num_pads are non-zero and are smaller
than the actual number of elements inside the graph. This may happen
if the <constant>topology_version</constant> changed when compared
to the last time this ioctl was called. Userspace should usually
free the area for the pointers, zero the struct elements and call
this ioctl again.</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
</refentry>
<section id="media-controller-types">
<title>Types and flags used to represent the media graph elements</title>
<table frame="none" pgwide="1" id="media-entity-type">
<title>Media entity types</title>
<tgroup cols="2">
<colspec colname="c1"/>
<colspec colname="c2"/>
<tbody valign="top">
<row>
<entry><constant>MEDIA_ENT_F_UNKNOWN</constant> and <constant>MEDIA_ENT_F_V4L2_SUBDEV_UNKNOWN</constant></entry>
<entry>Unknown entity. That generally indicates that
a driver didn't initialize properly the entity, with is a Kernel bug</entry>
</row>
<row>
<entry><constant>MEDIA_ENT_F_IO_V4L</constant></entry>
<entry>Data streaming input and/or output entity.</entry>
</row>
<row>
<entry><constant>MEDIA_ENT_F_IO_VBI</constant></entry>
<entry>V4L VBI streaming input or output entity</entry>
</row>
<row>
<entry><constant>MEDIA_ENT_F_IO_SWRADIO</constant></entry>
<entry>V4L Software Digital Radio (SDR) streaming input or output entity</entry>
</row>
<row>
<entry><constant>MEDIA_ENT_F_IO_DTV</constant></entry>
<entry>DVB Digital TV streaming input or output entity</entry>
</row>
<row>
<entry><constant>MEDIA_ENT_F_DTV_DEMOD</constant></entry>
<entry>Digital TV demodulator entity.</entry>
</row>
<row>
<entry><constant>MEDIA_ENT_F_TS_DEMUX</constant></entry>
<entry>MPEG Transport stream demux entity. Could be implemented on hardware or in Kernelspace by the Linux DVB subsystem.</entry>
</row>
<row>
<entry><constant>MEDIA_ENT_F_DTV_CA</constant></entry>
<entry>Digital TV Conditional Access module (CAM) entity</entry>
</row>
<row>
<entry><constant>MEDIA_ENT_F_DTV_NET_DECAP</constant></entry>
<entry>Digital TV network ULE/MLE desencapsulation entity. Could be implemented on hardware or in Kernelspace</entry>
</row>
<row>
<entry><constant>MEDIA_ENT_F_CONN_RF</constant></entry>
<entry>Connector for a Radio Frequency (RF) signal.</entry>
</row>
<row>
<entry><constant>MEDIA_ENT_F_CONN_SVIDEO</constant></entry>
<entry>Connector for a S-Video signal.</entry>
</row>
<row>
<entry><constant>MEDIA_ENT_F_CONN_COMPOSITE</constant></entry>
<entry>Connector for a RGB composite signal.</entry>
</row>
<row>
<entry><constant>MEDIA_ENT_F_CONN_TEST</constant></entry>
<entry>Connector for a test generator.</entry>
</row>
<row>
<entry><constant>MEDIA_ENT_F_CAM_SENSOR</constant></entry>
<entry>Camera video sensor entity.</entry>
</row>
<row>
<entry><constant>MEDIA_ENT_F_FLASH</constant></entry>
<entry>Flash controller entity.</entry>
</row>
<row>
<entry><constant>MEDIA_ENT_F_LENS</constant></entry>
<entry>Lens controller entity.</entry>
</row>
<row>
<entry><constant>MEDIA_ENT_F_ATV_DECODER</constant></entry>
<entry>Analog video decoder, the basic function of the video decoder
is to accept analogue video from a wide variety of sources such as
broadcast, DVD players, cameras and video cassette recorders, in
either NTSC, PAL, SECAM or HD format, separating the stream
into its component parts, luminance and chrominance, and output
it in some digital video standard, with appropriate timing
signals.</entry>
</row>
<row>
<entry><constant>MEDIA_ENT_F_TUNER</constant></entry>
<entry>Digital TV, analog TV, radio and/or software radio tuner.</entry>
</row>
</tbody>
</tgroup>
</table>
<table frame="none" pgwide="1" id="media-entity-flag">
<title>Media entity flags</title>
<tgroup cols="2">
<colspec colname="c1"/>
<colspec colname="c2"/>
<tbody valign="top">
<row>
<entry><constant>MEDIA_ENT_FL_DEFAULT</constant></entry>
<entry>Default entity for its type. Used to discover the default
audio, VBI and video devices, the default camera sensor, ...</entry>
</row>
<row>
<entry><constant>MEDIA_ENT_FL_CONNECTOR</constant></entry>
<entry>The entity represents a data conector</entry>
</row>
</tbody>
</tgroup>
</table>
<table frame="none" pgwide="1" id="media-intf-type">
<title>Media interface types</title>
<tgroup cols="3">
<colspec colname="c1"/>
<colspec colname="c2"/>
<colspec colname="c3"/>
<tbody valign="top">
<row>
<entry><constant>MEDIA_INTF_T_DVB_FE</constant></entry>
<entry>Device node interface for the Digital TV frontend</entry>
<entry>typically, /dev/dvb/adapter?/frontend?</entry>
</row>
<row>
<entry><constant>MEDIA_INTF_T_DVB_DEMUX</constant></entry>
<entry>Device node interface for the Digital TV demux</entry>
<entry>typically, /dev/dvb/adapter?/demux?</entry>
</row>
<row>
<entry><constant>MEDIA_INTF_T_DVB_DVR</constant></entry>
<entry>Device node interface for the Digital TV DVR</entry>
<entry>typically, /dev/dvb/adapter?/dvr?</entry>
</row>
<row>
<entry><constant>MEDIA_INTF_T_DVB_CA</constant></entry>
<entry>Device node interface for the Digital TV Conditional Access</entry>
<entry>typically, /dev/dvb/adapter?/ca?</entry>
</row>
<row>
<entry><constant>MEDIA_INTF_T_DVB_FE</constant></entry>
<entry>Device node interface for the Digital TV network control</entry>
<entry>typically, /dev/dvb/adapter?/net?</entry>
</row>
<row>
<entry><constant>MEDIA_INTF_T_V4L_VIDEO</constant></entry>
<entry>Device node interface for video (V4L)</entry>
<entry>typically, /dev/video?</entry>
</row>
<row>
<entry><constant>MEDIA_INTF_T_V4L_VBI</constant></entry>
<entry>Device node interface for VBI (V4L)</entry>
<entry>typically, /dev/vbi?</entry>
</row>
<row>
<entry><constant>MEDIA_INTF_T_V4L_RADIO</constant></entry>
<entry>Device node interface for radio (V4L)</entry>
<entry>typically, /dev/vbi?</entry>
</row>
<row>
<entry><constant>MEDIA_INTF_T_V4L_SUBDEV</constant></entry>
<entry>Device node interface for a V4L subdevice</entry>
<entry>typically, /dev/v4l-subdev?</entry>
</row>
<row>
<entry><constant>MEDIA_INTF_T_V4L_SWRADIO</constant></entry>
<entry>Device node interface for Software Defined Radio (V4L)</entry>
<entry>typically, /dev/swradio?</entry>
</row>
</tbody>
</tgroup>
</table>
<table frame="none" pgwide="1" id="media-pad-flag">
<title>Media pad flags</title>
<tgroup cols="2">
<colspec colname="c1"/>
<colspec colname="c2"/>
<tbody valign="top">
<row>
<entry><constant>MEDIA_PAD_FL_SINK</constant></entry>
<entry>Input pad, relative to the entity. Input pads sink data and
are targets of links.</entry>
</row>
<row>
<entry><constant>MEDIA_PAD_FL_SOURCE</constant></entry>
<entry>Output pad, relative to the entity. Output pads source data
and are origins of links.</entry>
</row>
<row>
<entry><constant>MEDIA_PAD_FL_MUST_CONNECT</constant></entry>
<entry>If this flag is set and the pad is linked to any other
pad, then at least one of those links must be enabled for the
entity to be able to stream. There could be temporary reasons
(e.g. device configuration dependent) for the pad to need
enabled links even when this flag isn't set; the absence of the
flag doesn't imply there is none.</entry>
</row>
</tbody>
</tgroup>
</table>
<para>One and only one of <constant>MEDIA_PAD_FL_SINK</constant> and
<constant>MEDIA_PAD_FL_SOURCE</constant> must be set for every pad.</para>
<table frame="none" pgwide="1" id="media-link-flag">
<title>Media link flags</title>
<tgroup cols="2">
<colspec colname="c1"/>
<colspec colname="c2"/>
<tbody valign="top">
<row>
<entry><constant>MEDIA_LNK_FL_ENABLED</constant></entry>
<entry>The link is enabled and can be used to transfer media data.
When two or more links target a sink pad, only one of them can be
enabled at a time.</entry>
</row>
<row>
<entry><constant>MEDIA_LNK_FL_IMMUTABLE</constant></entry>
<entry>The link enabled state can't be modified at runtime. An
immutable link is always enabled.</entry>
</row>
<row>
<entry><constant>MEDIA_LNK_FL_DYNAMIC</constant></entry>
<entry>The link enabled state can be modified during streaming. This
flag is set by drivers and is read-only for applications.</entry>
</row>
<row>
<entry><constant>MEDIA_LNK_FL_LINK_TYPE</constant></entry>
<entry><para>This is a bitmask that defines the type of the link.
Currently, two types of links are supported:</para>
<para><constant>MEDIA_LNK_FL_DATA_LINK</constant>
if the link is between two pads</para>
<para><constant>MEDIA_LNK_FL_INTERFACE_LINK</constant>
if the link is between an interface and an entity</para></entry>
</row>
</tbody>
</tgroup>
</table>
</section>
......@@ -162,12 +162,15 @@
<sect1 id="Basic_defines">
<title>Basic defines</title>
<para>
At least you have to provide a mtd structure and
a storage for the ioremap'ed chip address.
You can allocate the mtd structure using kmalloc
or you can allocate it statically.
In case of static allocation you have to allocate
a nand_chip structure too.
At least you have to provide a nand_chip structure
and a storage for the ioremap'ed chip address.
You can allocate the nand_chip structure using
kmalloc or you can allocate it statically.
The NAND chip structure embeds an mtd structure
which will be registered to the MTD subsystem.
You can extract a pointer to the mtd structure
from a nand_chip pointer using the nand_to_mtd()
helper.
</para>
<para>
Kmalloc based example
......@@ -180,7 +183,6 @@ static void __iomem *baseaddr;
Static example
</para>
<programlisting>
static struct mtd_info board_mtd;
static struct nand_chip board_chip;
static void __iomem *baseaddr;
</programlisting>
......@@ -235,7 +237,7 @@ static void board_hwcontrol(struct mtd_info *mtd, int cmd)
<programlisting>
static void board_hwcontrol(struct mtd_info *mtd, int cmd)
{
struct nand_chip *this = (struct nand_chip *) mtd->priv;
struct nand_chip *this = mtd_to_nand(mtd);
switch(cmd){
case NAND_CTL_SETCLE: this->IO_ADDR_W |= CLE_ADRR_BIT; break;
case NAND_CTL_CLRCLE: this->IO_ADDR_W &amp;= ~CLE_ADRR_BIT; break;
......@@ -274,13 +276,15 @@ static int __init board_init (void)
int err = 0;
/* Allocate memory for MTD device structure and private data */
board_mtd = kzalloc(sizeof(struct mtd_info) + sizeof(struct nand_chip), GFP_KERNEL);
if (!board_mtd) {
this = kzalloc(sizeof(struct nand_chip), GFP_KERNEL);
if (!this) {
printk ("Unable to allocate NAND MTD device structure.\n");
err = -ENOMEM;
goto out;
}
board_mtd = nand_to_mtd(this);
/* map physical address */
baseaddr = ioremap(CHIP_PHYSICAL_ADDRESS, 1024);
if (!baseaddr) {
......@@ -289,11 +293,6 @@ static int __init board_init (void)
goto out_mtd;
}
/* Get pointer to private data */
this = (struct nand_chip *) ();
/* Link the private data with the MTD structure */
board_mtd->priv = this;
/* Set address of NAND IO lines */
this->IO_ADDR_R = baseaddr;
this->IO_ADDR_W = baseaddr;
......@@ -317,7 +316,7 @@ static int __init board_init (void)
out_ior:
iounmap(baseaddr);
out_mtd:
kfree (board_mtd);
kfree (this);
out:
return err;
}
......@@ -343,7 +342,7 @@ static void __exit board_cleanup (void)
iounmap(baseaddr);
/* Free the MTD device structure */
kfree (board_mtd);
kfree (mtd_to_nand(board_mtd));
}
module_exit(board_cleanup);
#endif
......@@ -399,7 +398,7 @@ static void board_select_chip (struct mtd_info *mtd, int chip)
<programlisting>
static void board_select_chip (struct mtd_info *mtd, int chip)
{
struct nand_chip *this = (struct nand_chip *) mtd->priv;
struct nand_chip *this = mtd_to_nand(mtd);
/* Deselect all chips */
this->IO_ADDR_R &amp;= ~BOARD_NAND_ADDR_MASK;
......
......@@ -209,7 +209,7 @@ tools. One such tool that is particularly recommended is the Linux
Cross-Reference project, which is able to present source code in a
self-referential, indexed webpage format. An excellent up-to-date
repository of the kernel code may be found at:
http://lxr.linux.no/+trees
http://lxr.free-electrons.com/
The development process
......
subdir-y := accounting auxdisplay blackfin connector \
filesystems filesystems ia64 laptops mic misc-devices \
networking pcmcia prctl ptp spi timers vDSO video4linux \
networking pcmcia prctl ptp timers vDSO video4linux \
watchdog
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style="fill:#ffff00;stroke:#000000;stroke-width:21;stroke-linecap:butt;stroke-linejoin:miter"
id="rect8" />
<!-- Line: box -->
<rect
x="2700"
y="0"
width="9000"
height="4275"
rx="0"
style="fill:#00ff00;stroke:#000000;stroke-width:21;stroke-linecap:butt;stroke-linejoin:miter"
id="rect10" />
<!-- Line: box -->
<rect
x="4050"
y="0"
width="6300"
height="2475"
rx="0"
style="fill:#87cfff;stroke:#000000;stroke-width:21;stroke-linecap:butt;stroke-linejoin:miter"
id="rect12" />
<!-- Text -->
<text
xml:space="preserve"
x="7200"
y="900"
font-style="normal"
font-weight="normal"
font-size="324"
id="text14"
sodipodi:linespacing="125%"
style="font-size:427.63009644px;font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;text-align:center;line-height:125%;writing-mode:lr-tb;text-anchor:middle;fill:#000000;font-family:Nimbus Sans L;-inkscape-font-specification:Nimbus Sans L"><tspan
style="font-size:427.63009644px;font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;text-align:center;line-height:125%;writing-mode:lr-tb;text-anchor:middle;font-family:Nimbus Sans L;-inkscape-font-specification:Nimbus Sans L"
id="tspan3017">Read-Mostly, Stale &amp;</tspan></text>
<!-- Text -->
<text
xml:space="preserve"
x="7200"
y="1350"
font-style="normal"
font-weight="normal"
font-size="324"
id="text16"
sodipodi:linespacing="125%"
style="font-size:427.63009644px;font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;text-align:center;line-height:125%;writing-mode:lr-tb;text-anchor:middle;fill:#000000;font-family:Nimbus Sans L;-inkscape-font-specification:Nimbus Sans L"><tspan
style="font-size:427.63009644px;font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;text-align:center;line-height:125%;writing-mode:lr-tb;text-anchor:middle;font-family:Nimbus Sans L;-inkscape-font-specification:Nimbus Sans L"
id="tspan3019">Inconsistent Data OK</tspan></text>
<!-- Text -->
<text
xml:space="preserve"
x="7200"
y="1800"
font-style="normal"
font-weight="normal"
font-size="324"
id="text18"
sodipodi:linespacing="125%"
style="font-size:427.63009644px;font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;text-align:center;line-height:125%;writing-mode:lr-tb;text-anchor:middle;fill:#000000;font-family:Nimbus Sans L;-inkscape-font-specification:Nimbus Sans L"><tspan
style="font-size:427.63009644px;font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;text-align:center;line-height:125%;writing-mode:lr-tb;text-anchor:middle;font-family:Nimbus Sans L;-inkscape-font-specification:Nimbus Sans L"
id="tspan3021">(RCU Works Great!!!)</tspan></text>
<!-- Text -->
<text
xml:space="preserve"
x="7200"
y="3825"
font-style="normal"
font-weight="normal"
font-size="324"
id="text20"
sodipodi:linespacing="125%"
style="font-size:427.63009644px;font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;text-align:center;line-height:125%;writing-mode:lr-tb;text-anchor:middle;fill:#000000;font-family:Nimbus Sans L;-inkscape-font-specification:Nimbus Sans L"><tspan
style="font-size:427.63009644px;font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;text-align:center;line-height:125%;writing-mode:lr-tb;text-anchor:middle;font-family:Nimbus Sans L;-inkscape-font-specification:Nimbus Sans L"
id="tspan3023">(RCU Works Well)</tspan></text>
<!-- Text -->
<text
xml:space="preserve"
x="7200"
y="3375"
font-style="normal"
font-weight="normal"
font-size="324"
id="text22"
sodipodi:linespacing="125%"
style="font-size:427.63009644px;font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;text-align:center;line-height:125%;writing-mode:lr-tb;text-anchor:middle;fill:#000000;font-family:Nimbus Sans L;-inkscape-font-specification:Nimbus Sans L"><tspan
style="font-size:427.63009644px;font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;text-align:center;line-height:125%;writing-mode:lr-tb;text-anchor:middle;font-family:Nimbus Sans L;-inkscape-font-specification:Nimbus Sans L"
id="tspan3025">Read-Mostly, Need Consistent Data</tspan></text>
<!-- Text -->
<text
xml:space="preserve"
x="7200"
y="5175"
font-style="normal"
font-weight="normal"
font-size="324"
id="text24"
sodipodi:linespacing="125%"
style="font-size:427.63009644px;font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;text-align:center;line-height:125%;writing-mode:lr-tb;text-anchor:middle;fill:#000000;font-family:Nimbus Sans L;-inkscape-font-specification:Nimbus Sans L"><tspan
style="font-size:427.63009644px;font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;text-align:center;line-height:125%;writing-mode:lr-tb;text-anchor:middle;font-family:Nimbus Sans L;-inkscape-font-specification:Nimbus Sans L"
id="tspan3027">Read-Write, Need Consistent Data</tspan></text>
<!-- Text -->
<text
xml:space="preserve"
x="7200"
y="6975"
font-style="normal"
font-weight="normal"
font-size="324"
id="text26"
style="font-size:427.63009644px;font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;text-align:center;line-height:125%;writing-mode:lr-tb;text-anchor:middle;fill:#000000;font-family:Nimbus Sans L;-inkscape-font-specification:Nimbus Sans L"
sodipodi:linespacing="125%">Update-Mostly, Need Consistent Data</text>
<!-- Text -->
<text
xml:space="preserve"
x="7200"
y="5625"
font-style="normal"
font-weight="normal"
font-size="324"
id="text28"
sodipodi:linespacing="125%"
style="font-size:427.63009644px;font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;text-align:center;line-height:125%;writing-mode:lr-tb;text-anchor:middle;fill:#000000;font-family:Nimbus Sans L;-inkscape-font-specification:Nimbus Sans L"><tspan
style="font-size:427.63009644px;font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;text-align:center;line-height:125%;writing-mode:lr-tb;text-anchor:middle;font-family:Nimbus Sans L;-inkscape-font-specification:Nimbus Sans L"
id="tspan3029">(RCU Might Be OK...)</tspan></text>
<!-- Text -->
<text
xml:space="preserve"
x="7200"
y="7875"
font-style="normal"
font-weight="normal"
font-size="324"
id="text30"
style="font-size:427.63009644px;font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;text-align:center;line-height:125%;writing-mode:lr-tb;text-anchor:middle;fill:#000000;font-family:Nimbus Sans L;-inkscape-font-specification:Nimbus Sans L"
sodipodi:linespacing="125%">(1) Provide Existence Guarantees For Update-Friendly Mechanisms</text>
<!-- Text -->
<text
xml:space="preserve"
x="7200"
y="8325"
font-style="normal"
font-weight="normal"
font-size="324"
id="text32"
style="font-size:427.63009644px;font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;text-align:center;line-height:125%;writing-mode:lr-tb;text-anchor:middle;fill:#000000;font-family:Nimbus Sans L;-inkscape-font-specification:Nimbus Sans L"
sodipodi:linespacing="125%">(2) Provide Wait-Free Read-Side Primitives for Real-Time Use)</text>
<!-- Text -->
<text
xml:space="preserve"
x="7200"
y="7425"
font-style="normal"
font-weight="normal"
font-size="324"
id="text34"
style="font-size:427.63009644px;font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;text-align:center;line-height:125%;writing-mode:lr-tb;text-anchor:middle;fill:#000000;font-family:Nimbus Sans L;-inkscape-font-specification:Nimbus Sans L"
sodipodi:linespacing="125%">(RCU is Very Unlikely to be the Right Tool For The Job, But it Can:</text>
</g>
</svg>
此差异已折叠。
#!/bin/sh
#
# Usage: sh htmlqqz.sh file
#
# Extracts and converts quick quizzes in a proto-HTML document file.htmlx.
# Commands, all of which must be on a line by themselves:
#
# "<p>@@QQ@@": Start of a quick quiz.
# "<p>@@QQA@@": Start of a quick-quiz answer.
# "<p>@@QQE@@": End of a quick-quiz answer, and thus of the quick quiz.
# "<p>@@QQAL@@": Place to put quick-quiz answer list.
#
# Places the result in file.html.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, you can access it online at
# http://www.gnu.org/licenses/gpl-2.0.html.
#
# Copyright (c) 2013 Paul E. McKenney, IBM Corporation.
fn=$1
if test ! -r $fn.htmlx
then
echo "Error: $fn.htmlx unreadable."
exit 1
fi
echo "<!-- DO NOT HAND EDIT. -->" > $fn.html
echo "<!-- Instead, edit $fn.htmlx and run 'sh htmlqqz.sh $fn' -->" >> $fn.html
awk < $fn.htmlx >> $fn.html '
state == "" && $1 != "<p>@@QQ@@" && $1 != "<p>@@QQAL@@" {
print $0;
if ($0 ~ /^<p>@@QQ/)
print "Bad Quick Quiz command: " NR " (expected <p>@@QQ@@ or <p>@@QQAL@@)." > "/dev/stderr"
next;
}
state == "" && $1 == "<p>@@QQ@@" {
qqn++;
qqlineno = NR;
haveqq = 1;
state = "qq";
print "<p><a name=\"Quick Quiz " qqn "\"><b>Quick Quiz " qqn "</b>:</a>"
next;
}
state == "qq" && $1 != "<p>@@QQA@@" {
qq[qqn] = qq[qqn] $0 "\n";
print $0
if ($0 ~ /^<p>@@QQ/)
print "Bad Quick Quiz command: " NR ". (expected <p>@@QQA@@)" > "/dev/stderr"
next;
}
state == "qq" && $1 == "<p>@@QQA@@" {
state = "qqa";
print "<br><a href=\"#qq" qqn "answer\">Answer</a>"
next;
}
state == "qqa" && $1 != "<p>@@QQE@@" {
qqa[qqn] = qqa[qqn] $0 "\n";
if ($0 ~ /^<p>@@QQ/)
print "Bad Quick Quiz command: " NR " (expected <p>@@QQE@@)." > "/dev/stderr"
next;
}
state == "qqa" && $1 == "<p>@@QQE@@" {
state = "";
next;
}
state == "" && $1 == "<p>@@QQAL@@" {
haveqq = "";
print "<h3><a name=\"Answers to Quick Quizzes\">"
print "Answers to Quick Quizzes</a></h3>"
print "";
for (i = 1; i <= qqn; i++) {
print "<a name=\"qq" i "answer\"></a>"
print "<p><b>Quick Quiz " i "</b>:"
print qq[i];
print "";
print "</p><p><b>Answer</b>:"
print qqa[i];
print "";
print "</p><p><a href=\"#Quick%20Quiz%20" i "\"><b>Back to Quick Quiz " i "</b>.</a>"
print "";
}
next;
}
END {
if (state != "")
print "Unterminated Quick Quiz: " qqlineno "." > "/dev/stderr"
else if (haveqq)
print "Missing \"<p>@@QQAL@@\", no Quick Quiz." > "/dev/stderr"
}'
......@@ -375,7 +375,8 @@ int main(int argc, char *argv[])
}
}
if ((nl_sd = create_nl_socket(NETLINK_GENERIC)) < 0)
nl_sd = create_nl_socket(NETLINK_GENERIC);
if (nl_sd < 0)
err(1, "error creating Netlink socket\n");
......
......@@ -233,29 +233,30 @@ MMP/MMP2 family (communication processor)
Linux kernel mach directory: arch/arm/mach-mmp
Linux kernel plat directory: arch/arm/plat-pxa
Berlin family (Digital Entertainment)
Berlin family (Multimedia Solutions)
-------------------------------------
Flavors:
88DE3005, Armada 1500-mini
88DE3005, Armada 1500 Mini
Design name: BG2CD
Core: ARM Cortex-A9, PL310 L2CC
Homepage: http://www.marvell.com/digital-entertainment/armada-1500-mini/
Homepage: http://www.marvell.com/multimedia-solutions/armada-1500-mini/
88DE3006, Armada 1500 Mini Plus
Design name: BG2CDP
Core: Dual Core ARM Cortex-A7
Homepage: http://www.marvell.com/multimedia-solutions/armada-1500-mini-plus/
88DE3100, Armada 1500
Design name: BG2
Core: Marvell PJ4B (ARMv7), Tauros3 L2CC
Homepage: http://www.marvell.com/digital-entertainment/armada-1500/
Product Brief: http://www.marvell.com/digital-entertainment/armada-1500/assets/Marvell-ARMADA-1500-Product-Brief.pdf
Product Brief: http://www.marvell.com/multimedia-solutions/armada-1500/assets/Marvell-ARMADA-1500-Product-Brief.pdf
88DE3114, Armada 1500 Pro
Design name: BG2-Q
Design name: BG2Q
Core: Quad Core ARM Cortex-A9, PL310 L2CC
Homepage: http://www.marvell.com/digital-entertainment/armada-1500-pro/
Product Brief: http://www.marvell.com/digital-entertainment/armada-1500-pro/assets/Marvell_ARMADA_1500_PRO-01_product_brief.pdf
88DE????
Design name: BG3
Core: ARM Cortex-A15, CA15 integrated L2CC
Homepage: http://www.marvell.com/digital-entertainment/
Homepage: http://www.marvell.com/multimedia-solutions/
Directory: arch/arm/mach-berlin
Comments:
......
......@@ -49,24 +49,6 @@ specified through DTS. Following are the DTS used:-
The device tree documentation for the keystone machines are located at
Documentation/devicetree/bindings/arm/keystone/keystone.txt
Known issues & workaround
-------------------------
Some of the device drivers used on keystone are re-used from that from
DaVinci and other TI SoCs. These device drivers may use clock APIs directly.
Some of the keystone specific drivers such as netcp uses run time power
management API instead to enable clock. As this API has limitations on
keystone, following workaround is needed to boot Linux.
Add 'clk_ignore_unused' to the bootargs env variable in u-boot. Otherwise
clock frameworks will try to disable clocks that are unused and disable
the hardware. This is because netcp related power domain and clock
domains are enabled in u-boot as run time power management API currently
doesn't enable clocks for netcp due to a limitation. This workaround is
expected to be removed in the future when proper API support becomes
available. Until then, this work around is needed.
Document Author
---------------
Murali Karicheri <m-karicheri2@ti.com>
......
......@@ -49,7 +49,7 @@ to this new MFP mechanism, here are several key points:
internal controllers like PWM, SSP and UART, with 128 internal signals
which can be routed to external through one or more MFPs (e.g. GPIO<0>
can be routed through either MFP_PIN_GPIO0 as well as MFP_PIN_GPIO0_2,
see arch/arm/mach-pxa/mach/include/mfp-pxa300.h)
see arch/arm/mach-pxa/mfp-pxa300.h)
2. Alternate function configuration is removed from this GPIO controller,
the remaining functions are pure GPIO-specific, i.e.
......@@ -76,11 +76,11 @@ For board code writers, here are some guidelines:
1. include ONE of the following header files in your <board>.c:
- #include <mach/mfp-pxa25x.h>
- #include <mach/mfp-pxa27x.h>
- #include <mach/mfp-pxa300.h>
- #include <mach/mfp-pxa320.h>
- #include <mach/mfp-pxa930.h>
- #include "mfp-pxa25x.h"
- #include "mfp-pxa27x.h"
- #include "mfp-pxa300.h"
- #include "mfp-pxa320.h"
- #include "mfp-pxa930.h"
NOTE: only one file in your <board>.c, depending on the processors used,
because pin configuration definitions may conflict in these file (i.e.
......@@ -203,20 +203,20 @@ make them effective there-after.
1. Unified pin definitions - enum constants for all configurable pins
2. processor-neutral bit definitions for a possible MFP configuration
- arch/arm/mach-pxa/include/mach/mfp-pxa3xx.h
- arch/arm/mach-pxa/mfp-pxa3xx.h
for PXA3xx specific MFPR register bit definitions and PXA3xx common pin
configurations
- arch/arm/mach-pxa/include/mach/mfp-pxa2xx.h
- arch/arm/mach-pxa/mfp-pxa2xx.h
for PXA2xx specific definitions and PXA25x/PXA27x common pin configurations
- arch/arm/mach-pxa/include/mach/mfp-pxa25x.h
arch/arm/mach-pxa/include/mach/mfp-pxa27x.h
arch/arm/mach-pxa/include/mach/mfp-pxa300.h
arch/arm/mach-pxa/include/mach/mfp-pxa320.h
arch/arm/mach-pxa/include/mach/mfp-pxa930.h
- arch/arm/mach-pxa/mfp-pxa25x.h
arch/arm/mach-pxa/mfp-pxa27x.h
arch/arm/mach-pxa/mfp-pxa300.h
arch/arm/mach-pxa/mfp-pxa320.h
arch/arm/mach-pxa/mfp-pxa930.h
for processor specific definitions
......
Silicon Errata and Software Workarounds
=======================================
Author: Will Deacon <will.deacon@arm.com>
Date : 27 November 2015
It is an unfortunate fact of life that hardware is often produced with
so-called "errata", which can cause it to deviate from the architecture
under specific circumstances. For hardware produced by ARM, these
errata are broadly classified into the following categories:
Category A: A critical error without a viable workaround.
Category B: A significant or critical error with an acceptable
workaround.
Category C: A minor error that is not expected to occur under normal
operation.
For more information, consult one of the "Software Developers Errata
Notice" documents available on infocenter.arm.com (registration
required).
As far as Linux is concerned, Category B errata may require some special
treatment in the operating system. For example, avoiding a particular
sequence of code, or configuring the processor in a particular way. A
less common situation may require similar actions in order to declassify
a Category A erratum into a Category C erratum. These are collectively
known as "software workarounds" and are only required in the minority of
cases (e.g. those cases that both require a non-secure workaround *and*
can be triggered by Linux).
For software workarounds that may adversely impact systems unaffected by
the erratum in question, a Kconfig entry is added under "Kernel
Features" -> "ARM errata workarounds via the alternatives framework".
These are enabled by default and patched in at runtime when an affected
CPU is detected. For less-intrusive workarounds, a Kconfig option is not
available and the code is structured (preferably with a comment) in such
a way that the erratum will not be hit.
This approach can make it slightly onerous to determine exactly which
errata are worked around in an arbitrary kernel source tree, so this
file acts as a registry of software workarounds in the Linux Kernel and
will be updated when new workarounds are committed and backported to
stable kernels.
| Implementor | Component | Erratum ID | Kconfig |
+----------------+-----------------+-----------------+-------------------------+
| ARM | Cortex-A53 | #826319 | ARM64_ERRATUM_826319 |
| ARM | Cortex-A53 | #827319 | ARM64_ERRATUM_827319 |
| ARM | Cortex-A53 | #824069 | ARM64_ERRATUM_824069 |
| ARM | Cortex-A53 | #819472 | ARM64_ERRATUM_819472 |
| ARM | Cortex-A53 | #845719 | ARM64_ERRATUM_845719 |
| ARM | Cortex-A53 | #843419 | ARM64_ERRATUM_843419 |
| ARM | Cortex-A57 | #832075 | ARM64_ERRATUM_832075 |
| ARM | Cortex-A57 | #852523 | N/A |
| ARM | Cortex-A57 | #834220 | ARM64_ERRATUM_834220 |
| | | | |
| Cavium | ThunderX ITS | #22375, #24313 | CAVIUM_ERRATUM_22375 |
| Cavium | ThunderX GICv3 | #23154 | CAVIUM_ERRATUM_23154 |
......@@ -81,14 +81,13 @@ on higher end storage.
Default value for this parameter is 8ms.
latency
-------
This parameter is used to enable/disable the latency mode of the CFQ
scheduler. If latency mode (called low_latency) is enabled, CFQ tries
to recompute the slice time for each process based on the target_latency set
for the system. This favors fairness over throughput. Disabling low
latency (setting it to 0) ignores target latency, allowing each process in the
system to get a full time slice.
low_latency
-----------
This parameter is used to enable/disable the low latency mode of the CFQ
scheduler. If enabled, CFQ tries to recompute the slice time for each process
based on the target_latency set for the system. This favors fairness over
throughput. Disabling low latency (setting it to 0) ignores target latency,
allowing each process in the system to get a full time slice.
By default low latency mode is enabled.
......
......@@ -70,3 +70,6 @@ use_per_node_hctx=[0/1]: Default: 0
parameter.
1: The multi-queue block layer is instantiated with a hardware dispatch
queue for each CPU node in the system.
use_lightnvm=[0/1]: Default: 0
Register device with LightNVM. Requires blk-mq to be used.
00-INDEX
- this file
blkio-controller.txt
- Description for Block IO Controller, implementation and usage details.
cgroups.txt
- Control Groups definition, implementation details, examples and API.
cpuacct.txt
- CPU Accounting Controller; account CPU usage for groups of tasks.
cpusets.txt
- documents the cpusets feature; assign CPUs and Mem to a set of tasks.
devices.txt
- Device Whitelist Controller; description, interface and security.
freezer-subsystem.txt
- checkpointing; rationale to not use signals, interface.
hugetlb.txt
- HugeTLB Controller implementation and usage details.
memcg_test.txt
- Memory Resource Controller; implementation details.
memory.txt
- Memory Resource Controller; design, accounting, interface, testing.
net_cls.txt
- Network classifier cgroups details and usages.
net_prio.txt
- Network priority cgroups details and usages.
pids.txt
- Process number cgroups details and usages.
unified-hierarchy.txt
- Description the new/next cgroup interface.
Block IO Controller
===================
Overview
========
cgroup subsys "blkio" implements the block io controller. There seems to be
a need of various kinds of IO control policies (like proportional BW, max BW)
both at leaf nodes as well as at intermediate nodes in a storage hierarchy.
Plan is to use the same cgroup based management interface for blkio controller
and based on user options switch IO policies in the background.
Currently two IO control policies are implemented. First one is proportional
weight time based division of disk policy. It is implemented in CFQ. Hence
this policy takes effect only on leaf nodes when CFQ is being used. The second
one is throttling policy which can be used to specify upper IO rate limits
on devices. This policy is implemented in generic block layer and can be
used on leaf nodes as well as higher level logical devices like device mapper.
HOWTO
=====
Proportional Weight division of bandwidth
-----------------------------------------
You can do a very simple testing of running two dd threads in two different
cgroups. Here is what you can do.
- Enable Block IO controller
CONFIG_BLK_CGROUP=y
- Enable group scheduling in CFQ
CONFIG_CFQ_GROUP_IOSCHED=y
- Compile and boot into kernel and mount IO controller (blkio); see
cgroups.txt, Why are cgroups needed?.
mount -t tmpfs cgroup_root /sys/fs/cgroup
mkdir /sys/fs/cgroup/blkio
mount -t cgroup -o blkio none /sys/fs/cgroup/blkio
- Create two cgroups
mkdir -p /sys/fs/cgroup/blkio/test1/ /sys/fs/cgroup/blkio/test2
- Set weights of group test1 and test2
echo 1000 > /sys/fs/cgroup/blkio/test1/blkio.weight
echo 500 > /sys/fs/cgroup/blkio/test2/blkio.weight
- Create two same size files (say 512MB each) on same disk (file1, file2) and
launch two dd threads in different cgroup to read those files.
sync
echo 3 > /proc/sys/vm/drop_caches
dd if=/mnt/sdb/zerofile1 of=/dev/null &
echo $! > /sys/fs/cgroup/blkio/test1/tasks
cat /sys/fs/cgroup/blkio/test1/tasks
dd if=/mnt/sdb/zerofile2 of=/dev/null &
echo $! > /sys/fs/cgroup/blkio/test2/tasks
cat /sys/fs/cgroup/blkio/test2/tasks
- At macro level, first dd should finish first. To get more precise data, keep
on looking at (with the help of script), at blkio.disk_time and
blkio.disk_sectors files of both test1 and test2 groups. This will tell how
much disk time (in milliseconds), each group got and how many sectors each
group dispatched to the disk. We provide fairness in terms of disk time, so
ideally io.disk_time of cgroups should be in proportion to the weight.
Throttling/Upper Limit policy
-----------------------------
- Enable Block IO controller
CONFIG_BLK_CGROUP=y
- Enable throttling in block layer
CONFIG_BLK_DEV_THROTTLING=y
- Mount blkio controller (see cgroups.txt, Why are cgroups needed?)
mount -t cgroup -o blkio none /sys/fs/cgroup/blkio
- Specify a bandwidth rate on particular device for root group. The format
for policy is "<major>:<minor> <bytes_per_second>".
echo "8:16 1048576" > /sys/fs/cgroup/blkio/blkio.throttle.read_bps_device
Above will put a limit of 1MB/second on reads happening for root group
on device having major/minor number 8:16.
- Run dd to read a file and see if rate is throttled to 1MB/s or not.
# dd iflag=direct if=/mnt/common/zerofile of=/dev/null bs=4K count=1024
1024+0 records in
1024+0 records out
4194304 bytes (4.2 MB) copied, 4.0001 s, 1.0 MB/s
Limits for writes can be put using blkio.throttle.write_bps_device file.
Hierarchical Cgroups
====================
Both CFQ and throttling implement hierarchy support; however,
throttling's hierarchy support is enabled iff "sane_behavior" is
enabled from cgroup side, which currently is a development option and
not publicly available.
If somebody created a hierarchy like as follows.
root
/ \
test1 test2
|
test3
CFQ by default and throttling with "sane_behavior" will handle the
hierarchy correctly. For details on CFQ hierarchy support, refer to
Documentation/block/cfq-iosched.txt. For throttling, all limits apply
to the whole subtree while all statistics are local to the IOs
directly generated by tasks in that cgroup.
Throttling without "sane_behavior" enabled from cgroup side will
practically treat all groups at same level as if it looks like the
following.
pivot
/ / \ \
root test1 test2 test3
Various user visible config options
===================================
CONFIG_BLK_CGROUP
- Block IO controller.
CONFIG_DEBUG_BLK_CGROUP
- Debug help. Right now some additional stats file show up in cgroup
if this option is enabled.
CONFIG_CFQ_GROUP_IOSCHED
- Enables group scheduling in CFQ. Currently only 1 level of group
creation is allowed.
CONFIG_BLK_DEV_THROTTLING
- Enable block device throttling support in block layer.
Details of cgroup files
=======================
Proportional weight policy files
--------------------------------
- blkio.weight
- Specifies per cgroup weight. This is default weight of the group
on all the devices until and unless overridden by per device rule.
(See blkio.weight_device).
Currently allowed range of weights is from 10 to 1000.
- blkio.weight_device
- One can specify per cgroup per device rules using this interface.
These rules override the default value of group weight as specified
by blkio.weight.
Following is the format.
# echo dev_maj:dev_minor weight > blkio.weight_device
Configure weight=300 on /dev/sdb (8:16) in this cgroup
# echo 8:16 300 > blkio.weight_device
# cat blkio.weight_device
dev weight
8:16 300
Configure weight=500 on /dev/sda (8:0) in this cgroup
# echo 8:0 500 > blkio.weight_device
# cat blkio.weight_device
dev weight
8:0 500
8:16 300
Remove specific weight for /dev/sda in this cgroup
# echo 8:0 0 > blkio.weight_device
# cat blkio.weight_device
dev weight
8:16 300
- blkio.leaf_weight[_device]
- Equivalents of blkio.weight[_device] for the purpose of
deciding how much weight tasks in the given cgroup has while
competing with the cgroup's child cgroups. For details,
please refer to Documentation/block/cfq-iosched.txt.
- blkio.time
- disk time allocated to cgroup per device in milliseconds. First
two fields specify the major and minor number of the device and
third field specifies the disk time allocated to group in
milliseconds.
- blkio.sectors
- number of sectors transferred to/from disk by the group. First
two fields specify the major and minor number of the device and
third field specifies the number of sectors transferred by the
group to/from the device.
- blkio.io_service_bytes
- Number of bytes transferred to/from the disk by the group. These
are further divided by the type of operation - read or write, sync
or async. First two fields specify the major and minor number of the
device, third field specifies the operation type and the fourth field
specifies the number of bytes.
- blkio.io_serviced
- Number of IOs (bio) issued to the disk by the group. These
are further divided by the type of operation - read or write, sync
or async. First two fields specify the major and minor number of the
device, third field specifies the operation type and the fourth field
specifies the number of IOs.
- blkio.io_service_time
- Total amount of time between request dispatch and request completion
for the IOs done by this cgroup. This is in nanoseconds to make it
meaningful for flash devices too. For devices with queue depth of 1,
this time represents the actual service time. When queue_depth > 1,
that is no longer true as requests may be served out of order. This
may cause the service time for a given IO to include the service time
of multiple IOs when served out of order which may result in total
io_service_time > actual time elapsed. This time is further divided by
the type of operation - read or write, sync or async. First two fields
specify the major and minor number of the device, third field
specifies the operation type and the fourth field specifies the
io_service_time in ns.
- blkio.io_wait_time
- Total amount of time the IOs for this cgroup spent waiting in the
scheduler queues for service. This can be greater than the total time
elapsed since it is cumulative io_wait_time for all IOs. It is not a
measure of total time the cgroup spent waiting but rather a measure of
the wait_time for its individual IOs. For devices with queue_depth > 1
this metric does not include the time spent waiting for service once
the IO is dispatched to the device but till it actually gets serviced
(there might be a time lag here due to re-ordering of requests by the
device). This is in nanoseconds to make it meaningful for flash
devices too. This time is further divided by the type of operation -
read or write, sync or async. First two fields specify the major and
minor number of the device, third field specifies the operation type
and the fourth field specifies the io_wait_time in ns.
- blkio.io_merged
- Total number of bios/requests merged into requests belonging to this
cgroup. This is further divided by the type of operation - read or
write, sync or async.
- blkio.io_queued
- Total number of requests queued up at any given instant for this
cgroup. This is further divided by the type of operation - read or
write, sync or async.
- blkio.avg_queue_size
- Debugging aid only enabled if CONFIG_DEBUG_BLK_CGROUP=y.
The average queue size for this cgroup over the entire time of this
cgroup's existence. Queue size samples are taken each time one of the
queues of this cgroup gets a timeslice.
- blkio.group_wait_time
- Debugging aid only enabled if CONFIG_DEBUG_BLK_CGROUP=y.
This is the amount of time the cgroup had to wait since it became busy
(i.e., went from 0 to 1 request queued) to get a timeslice for one of
its queues. This is different from the io_wait_time which is the
cumulative total of the amount of time spent by each IO in that cgroup
waiting in the scheduler queue. This is in nanoseconds. If this is
read when the cgroup is in a waiting (for timeslice) state, the stat
will only report the group_wait_time accumulated till the last time it
got a timeslice and will not include the current delta.
- blkio.empty_time
- Debugging aid only enabled if CONFIG_DEBUG_BLK_CGROUP=y.
This is the amount of time a cgroup spends without any pending
requests when not being served, i.e., it does not include any time
spent idling for one of the queues of the cgroup. This is in
nanoseconds. If this is read when the cgroup is in an empty state,
the stat will only report the empty_time accumulated till the last
time it had a pending request and will not include the current delta.
- blkio.idle_time
- Debugging aid only enabled if CONFIG_DEBUG_BLK_CGROUP=y.
This is the amount of time spent by the IO scheduler idling for a
given cgroup in anticipation of a better request than the existing ones
from other queues/cgroups. This is in nanoseconds. If this is read
when the cgroup is in an idling state, the stat will only report the
idle_time accumulated till the last idle period and will not include
the current delta.
- blkio.dequeue
- Debugging aid only enabled if CONFIG_DEBUG_BLK_CGROUP=y. This
gives the statistics about how many a times a group was dequeued
from service tree of the device. First two fields specify the major
and minor number of the device and third field specifies the number
of times a group was dequeued from a particular device.
- blkio.*_recursive
- Recursive version of various stats. These files show the
same information as their non-recursive counterparts but
include stats from all the descendant cgroups.
Throttling/Upper limit policy files
-----------------------------------
- blkio.throttle.read_bps_device
- Specifies upper limit on READ rate from the device. IO rate is
specified in bytes per second. Rules are per device. Following is
the format.
echo "<major>:<minor> <rate_bytes_per_second>" > /cgrp/blkio.throttle.read_bps_device
- blkio.throttle.write_bps_device
- Specifies upper limit on WRITE rate to the device. IO rate is
specified in bytes per second. Rules are per device. Following is
the format.
echo "<major>:<minor> <rate_bytes_per_second>" > /cgrp/blkio.throttle.write_bps_device
- blkio.throttle.read_iops_device
- Specifies upper limit on READ rate from the device. IO rate is
specified in IO per second. Rules are per device. Following is
the format.
echo "<major>:<minor> <rate_io_per_second>" > /cgrp/blkio.throttle.read_iops_device
- blkio.throttle.write_iops_device
- Specifies upper limit on WRITE rate to the device. IO rate is
specified in io per second. Rules are per device. Following is
the format.
echo "<major>:<minor> <rate_io_per_second>" > /cgrp/blkio.throttle.write_iops_device
Note: If both BW and IOPS rules are specified for a device, then IO is
subjected to both the constraints.
- blkio.throttle.io_serviced
- Number of IOs (bio) issued to the disk by the group. These
are further divided by the type of operation - read or write, sync
or async. First two fields specify the major and minor number of the
device, third field specifies the operation type and the fourth field
specifies the number of IOs.
- blkio.throttle.io_service_bytes
- Number of bytes transferred to/from the disk by the group. These
are further divided by the type of operation - read or write, sync
or async. First two fields specify the major and minor number of the
device, third field specifies the operation type and the fourth field
specifies the number of bytes.
Common files among various policies
-----------------------------------
- blkio.reset_stats
- Writing an int to this file will result in resetting all the stats
for that cgroup.
CFQ sysfs tunable
=================
/sys/block/<disk>/queue/iosched/slice_idle
------------------------------------------
On a faster hardware CFQ can be slow, especially with sequential workload.
This happens because CFQ idles on a single queue and single queue might not
drive deeper request queue depths to keep the storage busy. In such scenarios
one can try setting slice_idle=0 and that would switch CFQ to IOPS
(IO operations per second) mode on NCQ supporting hardware.
That means CFQ will not idle between cfq queues of a cfq group and hence be
able to driver higher queue depth and achieve better throughput. That also
means that cfq provides fairness among groups in terms of IOPS and not in
terms of disk time.
/sys/block/<disk>/queue/iosched/group_idle
------------------------------------------
If one disables idling on individual cfq queues and cfq service trees by
setting slice_idle=0, group_idle kicks in. That means CFQ will still idle
on the group in an attempt to provide fairness among groups.
By default group_idle is same as slice_idle and does not do anything if
slice_idle is enabled.
One can experience an overall throughput drop if you have created multiple
groups and put applications in that group which are not driving enough
IO to keep disk busy. In that case set group_idle=0, and CFQ will not idle
on individual groups and throughput should improve.
此差异已折叠。
00-INDEX
- this file
blkio-controller.txt
- Description for Block IO Controller, implementation and usage details.
cgroups.txt
- Control Groups definition, implementation details, examples and API.
cpuacct.txt
- CPU Accounting Controller; account CPU usage for groups of tasks.
cpusets.txt
- documents the cpusets feature; assign CPUs and Mem to a set of tasks.
devices.txt
- Device Whitelist Controller; description, interface and security.
freezer-subsystem.txt
- checkpointing; rationale to not use signals, interface.
hugetlb.txt
- HugeTLB Controller implementation and usage details.
memcg_test.txt
- Memory Resource Controller; implementation details.
memory.txt
- Memory Resource Controller; design, accounting, interface, testing.
net_cls.txt
- Network classifier cgroups details and usages.
net_prio.txt
- Network priority cgroups details and usages.
pids.txt
- Process number cgroups details and usages.
resource_counter.txt
- Resource Counter API.
unified-hierarchy.txt
- Description the new/next cgroup interface.
Block IO Controller
===================
Overview
========
cgroup subsys "blkio" implements the block io controller. There seems to be
a need of various kinds of IO control policies (like proportional BW, max BW)
both at leaf nodes as well as at intermediate nodes in a storage hierarchy.
Plan is to use the same cgroup based management interface for blkio controller
and based on user options switch IO policies in the background.
Currently two IO control policies are implemented. First one is proportional
weight time based division of disk policy. It is implemented in CFQ. Hence
this policy takes effect only on leaf nodes when CFQ is being used. The second
one is throttling policy which can be used to specify upper IO rate limits
on devices. This policy is implemented in generic block layer and can be
used on leaf nodes as well as higher level logical devices like device mapper.
HOWTO
=====
Proportional Weight division of bandwidth
-----------------------------------------
You can do a very simple testing of running two dd threads in two different
cgroups. Here is what you can do.
- Enable Block IO controller
CONFIG_BLK_CGROUP=y
- Enable group scheduling in CFQ
CONFIG_CFQ_GROUP_IOSCHED=y
- Compile and boot into kernel and mount IO controller (blkio); see
cgroups.txt, Why are cgroups needed?.
mount -t tmpfs cgroup_root /sys/fs/cgroup
mkdir /sys/fs/cgroup/blkio
mount -t cgroup -o blkio none /sys/fs/cgroup/blkio
- Create two cgroups
mkdir -p /sys/fs/cgroup/blkio/test1/ /sys/fs/cgroup/blkio/test2
- Set weights of group test1 and test2
echo 1000 > /sys/fs/cgroup/blkio/test1/blkio.weight
echo 500 > /sys/fs/cgroup/blkio/test2/blkio.weight
- Create two same size files (say 512MB each) on same disk (file1, file2) and
launch two dd threads in different cgroup to read those files.
sync
echo 3 > /proc/sys/vm/drop_caches
dd if=/mnt/sdb/zerofile1 of=/dev/null &
echo $! > /sys/fs/cgroup/blkio/test1/tasks
cat /sys/fs/cgroup/blkio/test1/tasks
dd if=/mnt/sdb/zerofile2 of=/dev/null &
echo $! > /sys/fs/cgroup/blkio/test2/tasks
cat /sys/fs/cgroup/blkio/test2/tasks
- At macro level, first dd should finish first. To get more precise data, keep
on looking at (with the help of script), at blkio.disk_time and
blkio.disk_sectors files of both test1 and test2 groups. This will tell how
much disk time (in milliseconds), each group got and how many sectors each
group dispatched to the disk. We provide fairness in terms of disk time, so
ideally io.disk_time of cgroups should be in proportion to the weight.
Throttling/Upper Limit policy
-----------------------------
- Enable Block IO controller
CONFIG_BLK_CGROUP=y
- Enable throttling in block layer
CONFIG_BLK_DEV_THROTTLING=y
- Mount blkio controller (see cgroups.txt, Why are cgroups needed?)
mount -t cgroup -o blkio none /sys/fs/cgroup/blkio
- Specify a bandwidth rate on particular device for root group. The format
for policy is "<major>:<minor> <bytes_per_second>".
echo "8:16 1048576" > /sys/fs/cgroup/blkio/blkio.throttle.read_bps_device
Above will put a limit of 1MB/second on reads happening for root group
on device having major/minor number 8:16.
- Run dd to read a file and see if rate is throttled to 1MB/s or not.
# dd if=/mnt/common/zerofile of=/dev/null bs=4K count=1024
# iflag=direct
1024+0 records in
1024+0 records out
4194304 bytes (4.2 MB) copied, 4.0001 s, 1.0 MB/s
Limits for writes can be put using blkio.throttle.write_bps_device file.
Hierarchical Cgroups
====================
Both CFQ and throttling implement hierarchy support; however,
throttling's hierarchy support is enabled iff "sane_behavior" is
enabled from cgroup side, which currently is a development option and
not publicly available.
If somebody created a hierarchy like as follows.
root
/ \
test1 test2
|
test3
CFQ by default and throttling with "sane_behavior" will handle the
hierarchy correctly. For details on CFQ hierarchy support, refer to
Documentation/block/cfq-iosched.txt. For throttling, all limits apply
to the whole subtree while all statistics are local to the IOs
directly generated by tasks in that cgroup.
Throttling without "sane_behavior" enabled from cgroup side will
practically treat all groups at same level as if it looks like the
following.
pivot
/ / \ \
root test1 test2 test3
Various user visible config options
===================================
CONFIG_BLK_CGROUP
- Block IO controller.
CONFIG_DEBUG_BLK_CGROUP
- Debug help. Right now some additional stats file show up in cgroup
if this option is enabled.
CONFIG_CFQ_GROUP_IOSCHED
- Enables group scheduling in CFQ. Currently only 1 level of group
creation is allowed.
CONFIG_BLK_DEV_THROTTLING
- Enable block device throttling support in block layer.
Details of cgroup files
=======================
Proportional weight policy files
--------------------------------
- blkio.weight
- Specifies per cgroup weight. This is default weight of the group
on all the devices until and unless overridden by per device rule.
(See blkio.weight_device).
Currently allowed range of weights is from 10 to 1000.
- blkio.weight_device
- One can specify per cgroup per device rules using this interface.
These rules override the default value of group weight as specified
by blkio.weight.
Following is the format.
# echo dev_maj:dev_minor weight > blkio.weight_device
Configure weight=300 on /dev/sdb (8:16) in this cgroup
# echo 8:16 300 > blkio.weight_device
# cat blkio.weight_device
dev weight
8:16 300
Configure weight=500 on /dev/sda (8:0) in this cgroup
# echo 8:0 500 > blkio.weight_device
# cat blkio.weight_device
dev weight
8:0 500
8:16 300
Remove specific weight for /dev/sda in this cgroup
# echo 8:0 0 > blkio.weight_device
# cat blkio.weight_device
dev weight
8:16 300
- blkio.leaf_weight[_device]
- Equivalents of blkio.weight[_device] for the purpose of
deciding how much weight tasks in the given cgroup has while
competing with the cgroup's child cgroups. For details,
please refer to Documentation/block/cfq-iosched.txt.
- blkio.time
- disk time allocated to cgroup per device in milliseconds. First
two fields specify the major and minor number of the device and
third field specifies the disk time allocated to group in
milliseconds.
- blkio.sectors
- number of sectors transferred to/from disk by the group. First
two fields specify the major and minor number of the device and
third field specifies the number of sectors transferred by the
group to/from the device.
- blkio.io_service_bytes
- Number of bytes transferred to/from the disk by the group. These
are further divided by the type of operation - read or write, sync
or async. First two fields specify the major and minor number of the
device, third field specifies the operation type and the fourth field
specifies the number of bytes.
- blkio.io_serviced
- Number of IOs (bio) issued to the disk by the group. These
are further divided by the type of operation - read or write, sync
or async. First two fields specify the major and minor number of the
device, third field specifies the operation type and the fourth field
specifies the number of IOs.
- blkio.io_service_time
- Total amount of time between request dispatch and request completion
for the IOs done by this cgroup. This is in nanoseconds to make it
meaningful for flash devices too. For devices with queue depth of 1,
this time represents the actual service time. When queue_depth > 1,
that is no longer true as requests may be served out of order. This
may cause the service time for a given IO to include the service time
of multiple IOs when served out of order which may result in total
io_service_time > actual time elapsed. This time is further divided by
the type of operation - read or write, sync or async. First two fields
specify the major and minor number of the device, third field
specifies the operation type and the fourth field specifies the
io_service_time in ns.
- blkio.io_wait_time
- Total amount of time the IOs for this cgroup spent waiting in the
scheduler queues for service. This can be greater than the total time
elapsed since it is cumulative io_wait_time for all IOs. It is not a
measure of total time the cgroup spent waiting but rather a measure of
the wait_time for its individual IOs. For devices with queue_depth > 1
this metric does not include the time spent waiting for service once
the IO is dispatched to the device but till it actually gets serviced
(there might be a time lag here due to re-ordering of requests by the
device). This is in nanoseconds to make it meaningful for flash
devices too. This time is further divided by the type of operation -
read or write, sync or async. First two fields specify the major and
minor number of the device, third field specifies the operation type
and the fourth field specifies the io_wait_time in ns.
- blkio.io_merged
- Total number of bios/requests merged into requests belonging to this
cgroup. This is further divided by the type of operation - read or
write, sync or async.
- blkio.io_queued
- Total number of requests queued up at any given instant for this
cgroup. This is further divided by the type of operation - read or
write, sync or async.
- blkio.avg_queue_size
- Debugging aid only enabled if CONFIG_DEBUG_BLK_CGROUP=y.
The average queue size for this cgroup over the entire time of this
cgroup's existence. Queue size samples are taken each time one of the
queues of this cgroup gets a timeslice.
- blkio.group_wait_time
- Debugging aid only enabled if CONFIG_DEBUG_BLK_CGROUP=y.
This is the amount of time the cgroup had to wait since it became busy
(i.e., went from 0 to 1 request queued) to get a timeslice for one of
its queues. This is different from the io_wait_time which is the
cumulative total of the amount of time spent by each IO in that cgroup
waiting in the scheduler queue. This is in nanoseconds. If this is
read when the cgroup is in a waiting (for timeslice) state, the stat
will only report the group_wait_time accumulated till the last time it
got a timeslice and will not include the current delta.
- blkio.empty_time
- Debugging aid only enabled if CONFIG_DEBUG_BLK_CGROUP=y.
This is the amount of time a cgroup spends without any pending
requests when not being served, i.e., it does not include any time
spent idling for one of the queues of the cgroup. This is in
nanoseconds. If this is read when the cgroup is in an empty state,
the stat will only report the empty_time accumulated till the last
time it had a pending request and will not include the current delta.
- blkio.idle_time
- Debugging aid only enabled if CONFIG_DEBUG_BLK_CGROUP=y.
This is the amount of time spent by the IO scheduler idling for a
given cgroup in anticipation of a better request than the existing ones
from other queues/cgroups. This is in nanoseconds. If this is read
when the cgroup is in an idling state, the stat will only report the
idle_time accumulated till the last idle period and will not include
the current delta.
- blkio.dequeue
- Debugging aid only enabled if CONFIG_DEBUG_BLK_CGROUP=y. This
gives the statistics about how many a times a group was dequeued
from service tree of the device. First two fields specify the major
and minor number of the device and third field specifies the number
of times a group was dequeued from a particular device.
- blkio.*_recursive
- Recursive version of various stats. These files show the
same information as their non-recursive counterparts but
include stats from all the descendant cgroups.
Throttling/Upper limit policy files
-----------------------------------
- blkio.throttle.read_bps_device
- Specifies upper limit on READ rate from the device. IO rate is
specified in bytes per second. Rules are per device. Following is
the format.
echo "<major>:<minor> <rate_bytes_per_second>" > /cgrp/blkio.throttle.read_bps_device
- blkio.throttle.write_bps_device
- Specifies upper limit on WRITE rate to the device. IO rate is
specified in bytes per second. Rules are per device. Following is
the format.
echo "<major>:<minor> <rate_bytes_per_second>" > /cgrp/blkio.throttle.write_bps_device
- blkio.throttle.read_iops_device
- Specifies upper limit on READ rate from the device. IO rate is
specified in IO per second. Rules are per device. Following is
the format.
echo "<major>:<minor> <rate_io_per_second>" > /cgrp/blkio.throttle.read_iops_device
- blkio.throttle.write_iops_device
- Specifies upper limit on WRITE rate to the device. IO rate is
specified in io per second. Rules are per device. Following is
the format.
echo "<major>:<minor> <rate_io_per_second>" > /cgrp/blkio.throttle.write_iops_device
Note: If both BW and IOPS rules are specified for a device, then IO is
subjected to both the constraints.
- blkio.throttle.io_serviced
- Number of IOs (bio) issued to the disk by the group. These
are further divided by the type of operation - read or write, sync
or async. First two fields specify the major and minor number of the
device, third field specifies the operation type and the fourth field
specifies the number of IOs.
- blkio.throttle.io_service_bytes
- Number of bytes transferred to/from the disk by the group. These
are further divided by the type of operation - read or write, sync
or async. First two fields specify the major and minor number of the
device, third field specifies the operation type and the fourth field
specifies the number of bytes.
Common files among various policies
-----------------------------------
- blkio.reset_stats
- Writing an int to this file will result in resetting all the stats
for that cgroup.
CFQ sysfs tunable
=================
/sys/block/<disk>/queue/iosched/slice_idle
------------------------------------------
On a faster hardware CFQ can be slow, especially with sequential workload.
This happens because CFQ idles on a single queue and single queue might not
drive deeper request queue depths to keep the storage busy. In such scenarios
one can try setting slice_idle=0 and that would switch CFQ to IOPS
(IO operations per second) mode on NCQ supporting hardware.
That means CFQ will not idle between cfq queues of a cfq group and hence be
able to driver higher queue depth and achieve better throughput. That also
means that cfq provides fairness among groups in terms of IOPS and not in
terms of disk time.
/sys/block/<disk>/queue/iosched/group_idle
------------------------------------------
If one disables idling on individual cfq queues and cfq service trees by
setting slice_idle=0, group_idle kicks in. That means CFQ will still idle
on the group in an attempt to provide fairness among groups.
By default group_idle is same as slice_idle and does not do anything if
slice_idle is enabled.
One can experience an overall throughput drop if you have created multiple
groups and put applications in that group which are not driving enough
IO to keep disk busy. In that case set group_idle=0, and CFQ will not idle
on individual groups and throughput should improve.
Writeback
=========
Page cache is dirtied through buffered writes and shared mmaps and
written asynchronously to the backing filesystem by the writeback
mechanism. Writeback sits between the memory and IO domains and
regulates the proportion of dirty memory by balancing dirtying and
write IOs.
On traditional cgroup hierarchies, relationships between different
controllers cannot be established making it impossible for writeback
to operate accounting for cgroup resource restrictions and all
writeback IOs are attributed to the root cgroup.
If both the blkio and memory controllers are used on the v2 hierarchy
and the filesystem supports cgroup writeback, writeback operations
correctly follow the resource restrictions imposed by both memory and
blkio controllers.
Writeback examines both system-wide and per-cgroup dirty memory status
and enforces the more restrictive of the two. Also, writeback control
parameters which are absolute values - vm.dirty_bytes and
vm.dirty_background_bytes - are distributed across cgroups according
to their current writeback bandwidth.
There's a peculiarity stemming from the discrepancy in ownership
granularity between memory controller and writeback. While memory
controller tracks ownership per page, writeback operates on inode
basis. cgroup writeback bridges the gap by tracking ownership by
inode but migrating ownership if too many foreign pages, pages which
don't match the current inode ownership, have been encountered while
writing back the inode.
This is a conscious design choice as writeback operations are
inherently tied to inodes making strictly following page ownership
complicated and inefficient. The only use case which suffers from
this compromise is multiple cgroups concurrently dirtying disjoint
regions of the same inode, which is an unlikely use case and decided
to be unsupported. Note that as memory controller assigns page
ownership on the first use and doesn't update it until the page is
released, even if cgroup writeback strictly follows page ownership,
multiple cgroups dirtying overlapping areas wouldn't work as expected.
In general, write-sharing an inode across multiple cgroups is not well
supported.
Filesystem support for cgroup writeback
---------------------------------------
A filesystem can make writeback IOs cgroup-aware by updating
address_space_operations->writepage[s]() to annotate bio's using the
following two functions.
* wbc_init_bio(@wbc, @bio)
Should be called for each bio carrying writeback data and associates
the bio with the inode's owner cgroup. Can be called anytime
between bio allocation and submission.
* wbc_account_io(@wbc, @page, @bytes)
Should be called for each data segment being written out. While
this function doesn't care exactly when it's called during the
writeback session, it's the easiest and most natural to call it as
data segments are added to a bio.
With writeback bio's annotated, cgroup support can be enabled per
super_block by setting MS_CGROUPWB in ->s_flags. This allows for
selective disabling of cgroup writeback support which is helpful when
certain filesystem features, e.g. journaled data mode, are
incompatible.
wbc_init_bio() binds the specified bio to its cgroup. Depending on
the configuration, the bio may be executed at a lower priority and if
the writeback session is holding shared resources, e.g. a journal
entry, may lead to priority inversion. There is no one easy solution
for the problem. Filesystems can try to work around specific problem
cases by skipping wbc_init_bio() or using bio_associate_blkcg()
directly.
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......@@ -159,8 +159,8 @@ to be strictly associated with a P-state.
2.2 cpuinfo_transition_latency:
-------------------------------
The cpuinfo_transition_latency field is 0. The PCC specification does
not include a field to expose this value currently.
The cpuinfo_transition_latency field is CPUFREQ_ETERNAL. The PCC specification
does not include a field to expose this value currently.
2.3 cpuinfo_cur_freq:
---------------------
......
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Technologic Systems Platforms Device Tree Bindings
--------------------------------------------------
TS-4800 board
Required root node properties:
- compatible = "technologic,imx51-ts4800", "fsl,imx51";
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