Add infrastructure to track "maximum allowable latency" for power saving
policies.

The reason for adding this infrastructure is that power management in the
idle loop needs to make a tradeoff between latency and power savings
(deeper power save modes have a longer latency to running code again).  The
code that today makes this tradeoff just does a rather simple algorithm;
however this is not good enough: There are devices and use cases where a
lower latency is required than that the higher power saving states provide.
 An example would be audio playback, but another example is the ipw2100
wireless driver that right now has a very direct and ugly acpi hook to
disable some higher power states randomly when it gets certain types of
error.

The proposed solution is to have an interface where drivers can

* announce the maximum latency (in microseconds) that they can deal with
* modify this latency
* give up their constraint

and a function where the code that decides on power saving strategy can
query the current global desired maximum.

This patch has a user of each side: on the consumer side, ACPI is patched
to use this, on the producer side the ipw2100 driver is patched.

A generic maximum latency is also registered of 2 timer ticks (more and you
lose accurate time tracking after all).

While the existing users of the patch are x86 specific, the infrastructure
is not.  I'd like to ask the arch maintainers of other architectures if the
infrastructure is generic enough for their use (assuming the architecture
has such a tradeoff as concept at all), and the sound/multimedia driver
owners to look at the driver facing API to see if this is something they
can use.

[akpm@osdl.org: cleanups]
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Acked-by: NJesse Barnes <jesse.barnes@intel.com>
Cc: "Brown, Len" <len.brown@intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Conversion of booleans to: generic-boolean.patch (2006-08-23)
Signed-off-by: NRichard Knutsson <ricknu-0@student.ltu.se>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Conversion of booleans to: generic-boolean.patch (2006-08-23)
Signed-off-by: NRichard Knutsson <ricknu-0@student.ltu.se>
Cc: Dave Kleikamp <shaggy@austin.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Conversion of booleans to: generic-boolean.patch (2006-08-23)
Signed-off-by: NRichard Knutsson <ricknu-0@student.ltu.se>
Signed-off-by: NAnton Altaparmakov <aia21@cantab.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch defines:
* a generic boolean-type, named 'bool'
* aliases to 0 and 1, named 'false' and 'true'

Removing colliding definitions of 'bool', 'false' and 'true'.
Signed-off-by: NRichard Knutsson <ricknu-0@student.ltu.se>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

- Add soothing comment

- uninline thrice-called function

Cc: OGAWA Hirofumi <hogawa@miraclelinux.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The api for hot-add memory already has a construct for finding nodes based on
an address, memory_add_physaddr_to_nid.  This patch allows the fucntion to do
something besides return 0.  It uses the nodes_add infomation to lookup to
node info for a hot add event.
Signed-off-by: NKeith Mannthey <kmannth@us.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Migate CONFIG_MEMORY_HOTPLUG to CONFIG_MEMORY_HOTPLUG_SPARSE where needed.
Signed-off-by: NKeith Mannthey <kmannth@us.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

In cases where the acpi memory-add event does not containe the pxm (node)
infomation allow the driver to look up node info based on the address.  The
acpi_get_node call returns -1 if it can't decode the pxm info, this causes
add_memory to panic.  acpi_get_node would have to decode the resource from the
handle (a lenghty proposition).  This seems to be the cleanist point to
interject the hook.

[kamezawa.hiroyu@jp.fujitsu.com: build fixes]
[y-goto@jp.fujitsu.com: build fixes]
Signed-off-by: NKeith Mannthey <kmannth@us.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: NYasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The api for hot-add memory already has a construct for finding nodes based on
an address, memory_add_physaddr_to_nid.  This patch allows the fucntion to do
something besides return 0.  It uses the nodes_add infomation to lookup to
node info for a hot add event.
Signed-off-by: NKeith Mannthey <kmannth@us.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Enable x86_64 srat.c to share code between both reserve and sparsemem based
add memory paths.  Both paths need the hot-add area node locality infomration
(nodes_add).  This code refactors the code path to allow this.
Signed-off-by: NKeith Mannthey <kmannth@us.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Create Kconfig namespace for MEMORY_HOTPLUG_RESERVE and MEMORY_HOTPLUG_SPARSE.
 This is needed to create a disticiton between the 2 paths.  Selecting the
high level opiton of MEMORY_HOTPLUG will get you MEMORY_HOTPLUG_SPARSE if you
have sparsemem enabled or MEMORY_HOTPLUG_RESERVE if you are x86_64 with
discontig and ACPI numa support.
Signed-off-by: NKeith Mannthey <kmannth@us.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Fix up externs in memory_hotplug.c.  Cleanup.
Signed-off-by: NKeith Mannthey <kmannth@us.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This fixes two things

Firstly someone mistakenly used "errata" for the singular.  This causes
Dave Woodhouse to emit diagnostics whenever the string is read, and so
should be fixed.

Secondly the AMD AGP tunnel has an erratum which causes hangs if you try
and do direct PCI to AGP transfers in some cases.  We have a flag for
PCI/PCI failures but we need a different flag for this really as in this
case we don't want to stop PCI/PCI transfers using things like IOAT and the
new RAID offload work.

I'll post some updates to make proper use of the PCIAGP flag in the
media/video drivers to Mauro.
Signed-off-by: NAlan Cox <alan@redhat.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Don't try and give NULL to fput() in the error handling in do_mmap_pgoff()
as it'll cause an oops.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

These two BUG_ON()s are redundant and undesired: we're checking for this
condition further on in the function, only better.

Cc: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The ->flags in struct request was split into two variables, in a recent
changeset.  The merge of this change forgot to update SCSI's libsas,
probably because libsas was a very recent merge.
Signed-off-by: NJeff Garzik <jeff@garzik.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

device_reprobe() should return an error code.  When it does so,
scsi_device_reprobe() should propagate it back.
Acked-by: NJeff Garzik <jeff@garzik.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

* 'block' of git://brick.kernel.dk/data/git/linux-2.6-block:
  [PATCH] Only enable CONFIG_BLOCK option for embedded

It's too easy for people to shoot themselves in the foot, and it
only makes sense for embedded folks anyway.
Signed-off-by: NJens Axboe <axboe@kernel.dk>

* 'block' of git://brick.kernel.dk/data/git/linux-2.6-block: (67 commits)
  [PATCH] blk_queue_start_tag() shared map race fix
  [PATCH] Update axboe@suse.de email address
  [PATCH] fix creating zero sized bio mempools in low memory system
  [PATCH] CONFIG_BLOCK: blk_congestion_wait() fix
  [PATCH] CONFIG_BLOCK internal.h cleanups
  [PATCH] BLOCK: Make USB storage depend on SCSI rather than selecting it [try #6]
  [PATCH] BLOCK: Make it possible to disable the block layer [try #6]
  [PATCH] BLOCK: Remove no-longer necessary linux/buffer_head.h inclusions [try #6]
  [PATCH] BLOCK: Remove no-longer necessary linux/mpage.h inclusions [try #6]
  [PATCH] BLOCK: Move the msdos device ioctl compat stuff to the msdos driver [try #6]
  [PATCH] BLOCK: Move the Ext3 device ioctl compat stuff to the Ext3 driver [try #6]
  [PATCH] BLOCK: Move the Ext2 device ioctl compat stuff to the Ext2 driver [try #6]
  [PATCH] BLOCK: Move the ReiserFS device ioctl compat stuff to the ReiserFS driver [try #6]
  [PATCH] BLOCK: Move common FS-specific ioctls to linux/fs.h [try #6]
  [PATCH] BLOCK: Move the loop device ioctl compat stuff to the loop driver [try #6]
  [PATCH] BLOCK: Move __invalidate_device() to block_dev.c [try #6]
  [PATCH] BLOCK: Dissociate generic_writepages() from mpage stuff [try #6]
  [PATCH] BLOCK: Remove dependence on existence of blockdev_superblock [try #6]
  [PATCH] BLOCK: Move extern declarations out of fs/*.c into header files [try #6]
  [PATCH] BLOCK: Don't call block_sync_page() from AFS [try #6]
  ...

If we share the tag map between two or more queues, then we cannot
use __set_bit() to set the bit. In fact we need to make sure we
atomically acquire this tag, so loop using test_and_set_bit() to
protect from that.

Noticed by Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

As people often look for the copyright in files to see who to mail,
update the link to a neutral one.
Signed-off-by: NJens Axboe <axboe@kernel.dk>

In the very low memory systems is in the init_bio call
scale parameter set to zero and it leads to creating
zero sized mempool.

This patch prevents pool_entries parameter become zero,
so the created pool have at least 1 entry.

Mempool with 0 entries lead to incorrect behaviour
of mempool_free. (Alloc requests are not waken up
and system stalls in mempool_alloc->ioschedule).
Signed-off-by: NMilan Broz <mbroz@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Don't just do nothing: it'll cause busywaits all over writeback and page
reclaim.

For now, take a fixed-length nap.  Will improve when NFS starts waking up
throttled processes.
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

- forward declare struct superblock
- use inlines, not macros
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

This makes CONFIG_USB_STORAGE depend on CONFIG_SCSI rather than selecting it,
as selecting it makes CONFIG_USB_STORAGE override the dependencies of SCSI,
causing it to turn on even if they aren't all met.
Signed-Off-By: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Make it possible to disable the block layer.  Not all embedded devices require
it, some can make do with just JFFS2, NFS, ramfs, etc - none of which require
the block layer to be present.

This patch does the following:

 (*) Introduces CONFIG_BLOCK to disable the block layer, buffering and blockdev
     support.

 (*) Adds dependencies on CONFIG_BLOCK to any configuration item that controls
     an item that uses the block layer.  This includes:

     (*) Block I/O tracing.

     (*) Disk partition code.

     (*) All filesystems that are block based, eg: Ext3, ReiserFS, ISOFS.

     (*) The SCSI layer.  As far as I can tell, even SCSI chardevs use the
     	 block layer to do scheduling.  Some drivers that use SCSI facilities -
     	 such as USB storage - end up disabled indirectly from this.

     (*) Various block-based device drivers, such as IDE and the old CDROM
     	 drivers.

     (*) MTD blockdev handling and FTL.

     (*) JFFS - which uses set_bdev_super(), something it could avoid doing by
     	 taking a leaf out of JFFS2's book.

 (*) Makes most of the contents of linux/blkdev.h, linux/buffer_head.h and
     linux/elevator.h contingent on CONFIG_BLOCK being set.  sector_div() is,
     however, still used in places, and so is still available.

 (*) Also made contingent are the contents of linux/mpage.h, linux/genhd.h and
     parts of linux/fs.h.

 (*) Makes a number of files in fs/ contingent on CONFIG_BLOCK.

 (*) Makes mm/bounce.c (bounce buffering) contingent on CONFIG_BLOCK.

 (*) set_page_dirty() doesn't call __set_page_dirty_buffers() if CONFIG_BLOCK
     is not enabled.

 (*) fs/no-block.c is created to hold out-of-line stubs and things that are
     required when CONFIG_BLOCK is not set:

     (*) Default blockdev file operations (to give error ENODEV on opening).

 (*) Makes some /proc changes:

     (*) /proc/devices does not list any blockdevs.

     (*) /proc/diskstats and /proc/partitions are contingent on CONFIG_BLOCK.

 (*) Makes some compat ioctl handling contingent on CONFIG_BLOCK.

 (*) If CONFIG_BLOCK is not defined, makes sys_quotactl() return -ENODEV if
     given command other than Q_SYNC or if a special device is specified.

 (*) In init/do_mounts.c, no reference is made to the blockdev routines if
     CONFIG_BLOCK is not defined.  This does not prohibit NFS roots or JFFS2.

 (*) The bdflush, ioprio_set and ioprio_get syscalls can now be absent (return
     error ENOSYS by way of cond_syscall if so).

 (*) The seclvl_bd_claim() and seclvl_bd_release() security calls do nothing if
     CONFIG_BLOCK is not set, since they can't then happen.
Signed-Off-By: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Remove inclusions of linux/buffer_head.h that are no longer necessary due to the
transfer of a number of things out of there.
Signed-Off-By: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Remove inclusions of linux/mpage.h that are no longer necessary due to the
transfer of generic_writepages().
Signed-Off-By: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Move the msdos device ioctl compat stuff from fs/compat_ioctl.c to the msdos
driver so that the msdos header file doesn't need to be included.
Signed-Off-By: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Move the Ext3 device ioctl compat stuff from fs/compat_ioctl.c to the Ext3
driver so that the Ext3 header file doesn't need to be included.
Signed-Off-By: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Move the Ext2 device ioctl compat stuff from fs/compat_ioctl.c to the Ext2
driver so that the Ext2 header file doesn't need to be included.
Signed-Off-By: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Move the ReiserFS device ioctl compat stuff from fs/compat_ioctl.c to the
ReiserFS driver so that the ReiserFS header file doesn't need to be included.
Signed-Off-By: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Move common FS-specific ioctls from linux/ext2_fs.h to linux/fs.h as FS_IOC_*
and FS_IOC32_* and have the users of them use those as a base.

Also move the GETFLAGS/SETFLAGS flags to linux/fs.h as FS_*_FL macros, and then
have the other users use them as a base.
Signed-Off-By: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Move the loop device ioctl compat stuff from fs/compat_ioctl.c to the loop
driver so that the loop header file doesn't need to be included.
Signed-Off-By: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Move __invalidate_device() from fs/inode.c to fs/block_dev.c so that it can
more easily be disabled when the block layer is disabled.
Signed-Off-By: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Dissociate the generic_writepages() function from the mpage stuff, moving its
declaration to linux/mm.h and actually emitting a full implementation into
mm/page-writeback.c.

The implementation is a partial duplicate of mpage_writepages() with all BIO
references removed.

It is used by NFS to do writeback.
Signed-Off-By: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Move blockdev_superblock extern declaration from fs/fs-writeback.c to a
headerfile and remove the dependence on it by wrapping it in a macro.
Signed-Off-By: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Create a new header file, fs/internal.h, for common definitions local to the
sources in the fs/ directory.

Move extern definitions that should be in header files from fs/*.c to
fs/internal.h or other main header files where they span directories.
Signed-Off-By: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>