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  1. 09 3月, 2017 5 次提交
    • M
      staging, android: remove lowmemory killer from the tree · 915e70f9
      由 Michal Hocko 提交于 
      Lowmemory killer is sitting in the staging tree since 2008 without any
serious interest for fixing issues brought up by the MM folks. The main
objection is that the implementation is basically broken by design:
	- it hooks into slab shrinker API which is not suitable for this
	  purpose. lowmem_count implementation just shows this nicely.
	  There is no scaling based on the memory pressure and no
	  feedback to the generic shrinker infrastructure.
	  Moreover lowmem_scan is called way too often for the heavy
	  work it performs.
	- it is not reclaim context aware - no NUMA and/or memcg
	  awareness.

As the code stands right now it just adds a maintenance overhead when
core MM changes have to update lowmemorykiller.c as well. It also seems
that the alternative LMK implementation will be solely in the userspace
so this code has no perspective it seems. The staging tree is supposed
to be for a code which needs to be put in shape before it can be merged
which is not the case here obviously.
Signed-off-by: NMichal Hocko <mhocko@suse.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      915e70f9
    • M
      staging: vchiq_arm: Disable ability to dump memory by default · 12ab1659
      由 Michael Zoran 提交于 
      vc04_services has an ioctl interface to dump arbitrary memory
to a custom debug log.  This is typically only needed by
diagnostic tools, and can potentially be a security issue
if the devtmpfs node doesn't have adequate permissions set.

Since the ability to dump memory still has debugging value,
create a new build configuration and disable the feature
by default.
Signed-off-by: NMichael Zoran <mzoran@crowfest.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      12ab1659
    • M
      staging: vchiq_arm: Add compatibility wrappers for ioctls · 5569a126
      由 Michael Zoran 提交于 
      This patch adds compatibility wrappers for the ioctls
exposed by vchiq/vc04_services.  The compat ioctls are
completely implemented on top of the native ioctls.  No
existing lines are modified.

While the ideal approach would be to cleanup the existing
code, this path is simplier and easier to review. While
it does have a small runtime performance penality vs
seperating the existing code into wrapper+worker functions,
the penality is small since only the metadata is copied
back onto the 32 bit user mode stack.

The on top of approach is the approach used by several
existing performance critical subsystems of Linux such
as the DRM 3D graphics subsystem.

Testing:

1. A 32 bit chroot was created on a RPI 3 and vchiq_test
was built for armhf.  The usual tests were run such as
vchiq_test -f 10 and vchiq_test -p.

2. This patch was copied onto the shipping version of
the Linux kernel used for the RPI and that kernel was
built for arm64. That kernel was used to boot Raspbian.
Many of the builtin features are now functional such
as the "hello_pi" examples, and minecraft_pi.
Signed-off-by: NMichael Zoran <mzoran@crowfest.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      5569a126
    • M
      staging: bcm2835_camera: Use a mapping table for context field of mmal_msg_header · 4e6bafdf
      由 Michael Zoran 提交于 
      The camera driver passes messages back and forth between the firmware with
requests and replies.  One of the fields of the message header called
context is a pointer so the size changes between 32 bit and 64 bit.

The context field is used to pair reply messages from the firmware with
request messages from the kernel.  The simple solution would be
to use the padding field for the upper 32 bits of pointers, but this
would rely on the firmware always copying the pad field.

So instead handles are generated that are 32 bit numbers and a mapping
stored in a btree as implemented by the btree library in the kernel lib
directory.  The mapping pairs the handle with the pointer to the actual
data. The btree library was chosen since it's very easy to use and
red black trees would be overkill.

The camera driver also now forces in the btree library if the camera is
included in the build.  The btree library is a hidden configuration
option.
Signed-off-by: NMichael Zoran <mzoran@crowfest.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      4e6bafdf
    • M
      staging: bcm2835_camera: Convert control_service field of mmal_msg_header to u32 · 81b2cbdb
      由 Michael Zoran 提交于 
      The camera driver passes messages back and forth between the firmware with
requests and replies.  One of the fields of the message header called
control_service is a pointer so the size changes between 32 bit and 64 bit.

Luckly, the field is not interperated by the driver, so it can be changed
to a u32 which has a fixed size.
Signed-off-by: NMichael Zoran <mzoran@crowfest.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      81b2cbdb
  3. 08 3月, 2017 19 次提交
  5. 07 3月, 2017 8 次提交
  7. 06 3月, 2017 8 次提交