<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/arch/arm/mm, branch v4.4</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>Merge branch 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm</title>
<updated>2015-12-17T19:20:13+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2015-12-17T19:20:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=d7637d01bef21848d156a219626b6541ccc0a734'/>
<id>d7637d01bef21848d156a219626b6541ccc0a734</id>
<content type='text'>
Pull libnvdimm fixes from Dan Williams:

 - Two bug fixes for misuse of PAGE_MASK in scatterlist and dma-debug.
   These are tagged for -stable.  The scatterlist impact is potentially
  corrupted dma addresses on HIGHMEM enabled platforms.

 - A minor locking fix for the NFIT hot-add implementation that is new
   in 4.4-rc.  This would only trigger in the case a hot-add raced
   driver removal.

* 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  dma-debug: Fix dma_debug_entry offset calculation
  Revert "scatterlist: use sg_phys()"
  nfit: acpi_nfit_notify(): Do not leave device locked
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull libnvdimm fixes from Dan Williams:

 - Two bug fixes for misuse of PAGE_MASK in scatterlist and dma-debug.
   These are tagged for -stable.  The scatterlist impact is potentially
  corrupted dma addresses on HIGHMEM enabled platforms.

 - A minor locking fix for the NFIT hot-add implementation that is new
   in 4.4-rc.  This would only trigger in the case a hot-add raced
   driver removal.

* 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  dma-debug: Fix dma_debug_entry offset calculation
  Revert "scatterlist: use sg_phys()"
  nfit: acpi_nfit_notify(): Do not leave device locked
</pre>
</div>
</content>
</entry>
<entry>
<title>Revert "scatterlist: use sg_phys()"</title>
<updated>2015-12-15T20:54:06+00:00</updated>
<author>
<name>Dan Williams</name>
<email>dan.j.williams@intel.com</email>
</author>
<published>2015-12-15T20:54:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=3e6110fd5480f5f86ff31381f4dea14218284bff'/>
<id>3e6110fd5480f5f86ff31381f4dea14218284bff</id>
<content type='text'>
commit db0fa0cb0157 "scatterlist: use sg_phys()" did replacements of
the form:

    phys_addr_t phys = page_to_phys(sg_page(s));
    phys_addr_t phys = sg_phys(s) &amp; PAGE_MASK;

However, this breaks platforms where sizeof(phys_addr_t) &gt;
sizeof(unsigned long).  Revert for 4.3 and 4.4 to make room for a
combined helper in 4.5.

Cc: &lt;stable@vger.kernel.org&gt;
Cc: Jens Axboe &lt;axboe@fb.com&gt;
Cc: Christoph Hellwig &lt;hch@lst.de&gt;
Cc: Russell King &lt;linux@arm.linux.org.uk&gt;
Cc: David Woodhouse &lt;dwmw2@infradead.org&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Fixes: db0fa0cb0157 ("scatterlist: use sg_phys()")
Suggested-by: Joerg Roedel &lt;joro@8bytes.org&gt;
Reported-by: Vitaly Lavrov &lt;vel21ripn@gmail.com&gt;
Signed-off-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit db0fa0cb0157 "scatterlist: use sg_phys()" did replacements of
the form:

    phys_addr_t phys = page_to_phys(sg_page(s));
    phys_addr_t phys = sg_phys(s) &amp; PAGE_MASK;

However, this breaks platforms where sizeof(phys_addr_t) &gt;
sizeof(unsigned long).  Revert for 4.3 and 4.4 to make room for a
combined helper in 4.5.

Cc: &lt;stable@vger.kernel.org&gt;
Cc: Jens Axboe &lt;axboe@fb.com&gt;
Cc: Christoph Hellwig &lt;hch@lst.de&gt;
Cc: Russell King &lt;linux@arm.linux.org.uk&gt;
Cc: David Woodhouse &lt;dwmw2@infradead.org&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Fixes: db0fa0cb0157 ("scatterlist: use sg_phys()")
Suggested-by: Joerg Roedel &lt;joro@8bytes.org&gt;
Reported-by: Vitaly Lavrov &lt;vel21ripn@gmail.com&gt;
Signed-off-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ARM: 8471/1: need to save/restore arm register(r11) when it is corrupted</title>
<updated>2015-12-15T11:51:41+00:00</updated>
<author>
<name>Anson Huang</name>
<email>Anson.Huang@freescale.com</email>
</author>
<published>2015-12-07T09:09:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=fa0708b320f6da4c1104fe56e01b7abf66fd16ad'/>
<id>fa0708b320f6da4c1104fe56e01b7abf66fd16ad</id>
<content type='text'>
In cpu_v7_do_suspend routine, r11 is used while it is NOT
saved/restored, different compiler may have different usage
of ARM general registers, so it may cause issues during
calling cpu_v7_do_suspend.

We meet kernel fault occurs when using GCC 4.8.3, r11 contains
valid value before calling into cpu_v7_do_suspend, but when returned
from this routine, r11 is corrupted and lead to kernel fault.
Doing save/restore for those corrupted registers is a must in
assemble code.

Signed-off-by: Anson Huang &lt;Anson.Huang@freescale.com&gt;
Reviewed-by: Nicolas Pitre &lt;nico@linaro.org&gt;
Cc: &lt;stable@vger.kernel.org&gt; # v3.3+
Signed-off-by: Russell King &lt;rmk+kernel@arm.linux.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
In cpu_v7_do_suspend routine, r11 is used while it is NOT
saved/restored, different compiler may have different usage
of ARM general registers, so it may cause issues during
calling cpu_v7_do_suspend.

We meet kernel fault occurs when using GCC 4.8.3, r11 contains
valid value before calling into cpu_v7_do_suspend, but when returned
from this routine, r11 is corrupted and lead to kernel fault.
Doing save/restore for those corrupted registers is a must in
assemble code.

Signed-off-by: Anson Huang &lt;Anson.Huang@freescale.com&gt;
Reviewed-by: Nicolas Pitre &lt;nico@linaro.org&gt;
Cc: &lt;stable@vger.kernel.org&gt; # v3.3+
Signed-off-by: Russell King &lt;rmk+kernel@arm.linux.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ARM: 8464/1: Update all mm structures with section adjustments</title>
<updated>2015-12-04T19:20:34+00:00</updated>
<author>
<name>Laura Abbott</name>
<email>labbott@redhat.com</email>
</author>
<published>2015-11-30T18:36:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=08925c2f124f1bac6152a8b234268f9874fc70a5'/>
<id>08925c2f124f1bac6152a8b234268f9874fc70a5</id>
<content type='text'>
Currently, when updating section permissions to mark areas RO
or NX, the only mm updated is current-&gt;mm. This is working off
the assumption that there are no additional mm structures at
the time. This may not always hold true. (Example: calling
modprobe early will trigger a fork/exec). Ensure all mm structres
get updated with the new section information.

Reviewed-by: Kees Cook &lt;keescook@chromium.org&gt;
Signed-off-by: Laura Abbott &lt;labbott@fedoraproject.org&gt;
Signed-off-by: Russell King &lt;rmk+kernel@arm.linux.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Currently, when updating section permissions to mark areas RO
or NX, the only mm updated is current-&gt;mm. This is working off
the assumption that there are no additional mm structures at
the time. This may not always hold true. (Example: calling
modprobe early will trigger a fork/exec). Ensure all mm structres
get updated with the new section information.

Reviewed-by: Kees Cook &lt;keescook@chromium.org&gt;
Signed-off-by: Laura Abbott &lt;labbott@fedoraproject.org&gt;
Signed-off-by: Russell King &lt;rmk+kernel@arm.linux.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ARM: 8465/1: mm: keep reserved ASIDs in sync with mm after multiple rollovers</title>
<updated>2015-12-02T23:57:54+00:00</updated>
<author>
<name>Will Deacon</name>
<email>will.deacon@arm.com</email>
</author>
<published>2015-12-02T13:31:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=40ee068ec09b2d98162da5ea18b7c6fdbaa2bb71'/>
<id>40ee068ec09b2d98162da5ea18b7c6fdbaa2bb71</id>
<content type='text'>
Under some unusual context-switching patterns, it is possible to end up
with multiple threads from the same mm running concurrently with
different ASIDs:

1. CPU x schedules task t with mm p containing ASID a and generation g
   This task doesn't block and the CPU doesn't context switch.
   So:
     * per_cpu(active_asid, x) = {g,a}
     * p-&gt;context.id = {g,a}

2. Some other CPU generates an ASID rollover. The global generation is
   now (g + 1). CPU x is still running t, with no context switch and
   so per_cpu(reserved_asid, x) = {g,a}

3. CPU y schedules task t', which shares mm p with t. The generation
   mismatches, so we take the slowpath and hit the reserved ASID from
   CPU x. p is then updated so that p-&gt;context.id = {g + 1,a}

4. CPU y schedules some other task u, which has an mm != p.

5. Some other CPU generates *another* CPU rollover. The global
   generation is now (g + 2). CPU x is still running t, with no context
   switch and so per_cpu(reserved_asid, x) = {g,a}.

6. CPU y once again schedules task t', but now *fails* to hit the
   reserved ASID from CPU x because of the generation mismatch. This
   results in a new ASID being allocated, despite the fact that t is
   still running on CPU x with the same mm.

Consequently, TLBIs (e.g. as a result of CoW) will not be synchronised
between the two threads.

This patch fixes the problem by updating all of the matching reserved
ASIDs when we hit on the slowpath (i.e. in step 3 above). This keeps
the reserved ASIDs in-sync with the mm and avoids the problem.

Cc: &lt;stable@vger.kernel.org&gt;
Reported-by: Tony Thompson &lt;anthony.thompson@arm.com&gt;
Reviewed-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Signed-off-by: Will Deacon &lt;will.deacon@arm.com&gt;
Signed-off-by: Russell King &lt;rmk+kernel@arm.linux.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Under some unusual context-switching patterns, it is possible to end up
with multiple threads from the same mm running concurrently with
different ASIDs:

1. CPU x schedules task t with mm p containing ASID a and generation g
   This task doesn't block and the CPU doesn't context switch.
   So:
     * per_cpu(active_asid, x) = {g,a}
     * p-&gt;context.id = {g,a}

2. Some other CPU generates an ASID rollover. The global generation is
   now (g + 1). CPU x is still running t, with no context switch and
   so per_cpu(reserved_asid, x) = {g,a}

3. CPU y schedules task t', which shares mm p with t. The generation
   mismatches, so we take the slowpath and hit the reserved ASID from
   CPU x. p is then updated so that p-&gt;context.id = {g + 1,a}

4. CPU y schedules some other task u, which has an mm != p.

5. Some other CPU generates *another* CPU rollover. The global
   generation is now (g + 2). CPU x is still running t, with no context
   switch and so per_cpu(reserved_asid, x) = {g,a}.

6. CPU y once again schedules task t', but now *fails* to hit the
   reserved ASID from CPU x because of the generation mismatch. This
   results in a new ASID being allocated, despite the fact that t is
   still running on CPU x with the same mm.

Consequently, TLBIs (e.g. as a result of CoW) will not be synchronised
between the two threads.

This patch fixes the problem by updating all of the matching reserved
ASIDs when we hit on the slowpath (i.e. in step 3 above). This keeps
the reserved ASIDs in-sync with the mm and avoids the problem.

Cc: &lt;stable@vger.kernel.org&gt;
Reported-by: Tony Thompson &lt;anthony.thompson@arm.com&gt;
Reviewed-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Signed-off-by: Will Deacon &lt;will.deacon@arm.com&gt;
Signed-off-by: Russell King &lt;rmk+kernel@arm.linux.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'armsoc-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc</title>
<updated>2015-11-10T22:56:23+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2015-11-10T22:56:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=56e0464980febfa50432a070261579415c72664e'/>
<id>56e0464980febfa50432a070261579415c72664e</id>
<content type='text'>
Pull ARM SoC platform updates from Olof Johansson:
 "New and/or improved SoC support for this release:

  Marvell Berlin:
     - Enable standard DT-based cpufreq
     - Add CPU hotplug support

  Freescale:
     - Ethernet init for i.MX7D
     - Suspend/resume support for i.MX6UL

  Allwinner:
     - Support for R8 chipset (used on NTC's $9 C.H.I.P board)

  Mediatek:
     - SMP support for some platforms

  Uniphier:
     - L2 support
     - Cleaned up SMP support, etc.

  plus a handful of other patches around above functionality, and a few
  other smaller changes"

* tag 'armsoc-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (42 commits)
  ARM: uniphier: rework SMP operations to use trampoline code
  ARM: uniphier: add outer cache support
  Documentation: EXYNOS: Update bootloader interface on exynos542x
  ARM: mvebu: add broken-idle option
  ARM: orion5x: use mac_pton() helper
  ARM: at91: pm: at91_pm_suspend_in_sram() must be 8-byte aligned
  ARM: sunxi: Add R8 support
  ARM: digicolor: select pinctrl/gpio driver
  arm: berlin: add CPU hotplug support
  arm: berlin: use non-self-cleared reset register to reset cpu
  ARM: mediatek: add smp bringup code
  ARM: mediatek: enable gpt6 on boot up to make arch timer working
  soc: mediatek: Fix random hang up issue while kernel init
  soc: ti: qmss: make acc queue support optional in the driver
  soc: ti: add firmware file name as part of the driver
  Documentation: dt: soc: Add description for knav qmss driver
  ARM: S3C64XX: Use PWM lookup table for mach-smartq
  ARM: S3C64XX: Use PWM lookup table for mach-hmt
  ARM: S3C64XX: Use PWM lookup table for mach-crag6410
  ARM: S3C64XX: Use PWM lookup table for smdk6410
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull ARM SoC platform updates from Olof Johansson:
 "New and/or improved SoC support for this release:

  Marvell Berlin:
     - Enable standard DT-based cpufreq
     - Add CPU hotplug support

  Freescale:
     - Ethernet init for i.MX7D
     - Suspend/resume support for i.MX6UL

  Allwinner:
     - Support for R8 chipset (used on NTC's $9 C.H.I.P board)

  Mediatek:
     - SMP support for some platforms

  Uniphier:
     - L2 support
     - Cleaned up SMP support, etc.

  plus a handful of other patches around above functionality, and a few
  other smaller changes"

* tag 'armsoc-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (42 commits)
  ARM: uniphier: rework SMP operations to use trampoline code
  ARM: uniphier: add outer cache support
  Documentation: EXYNOS: Update bootloader interface on exynos542x
  ARM: mvebu: add broken-idle option
  ARM: orion5x: use mac_pton() helper
  ARM: at91: pm: at91_pm_suspend_in_sram() must be 8-byte aligned
  ARM: sunxi: Add R8 support
  ARM: digicolor: select pinctrl/gpio driver
  arm: berlin: add CPU hotplug support
  arm: berlin: use non-self-cleared reset register to reset cpu
  ARM: mediatek: add smp bringup code
  ARM: mediatek: enable gpt6 on boot up to make arch timer working
  soc: mediatek: Fix random hang up issue while kernel init
  soc: ti: qmss: make acc queue support optional in the driver
  soc: ti: add firmware file name as part of the driver
  Documentation: dt: soc: Add description for knav qmss driver
  ARM: S3C64XX: Use PWM lookup table for mach-smartq
  ARM: S3C64XX: Use PWM lookup table for mach-hmt
  ARM: S3C64XX: Use PWM lookup table for mach-crag6410
  ARM: S3C64XX: Use PWM lookup table for smdk6410
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>kmap_atomic_to_page() has no users, remove it</title>
<updated>2015-11-09T23:11:24+00:00</updated>
<author>
<name>Nicolas Pitre</name>
<email>nicolas.pitre@linaro.org</email>
</author>
<published>2015-11-09T22:58:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=77c5b5da02f0a30d61144a546c4ef3657e3b817d'/>
<id>77c5b5da02f0a30d61144a546c4ef3657e3b817d</id>
<content type='text'>
Removal started in commit 5bbeed12bdc3 ("sparc32: drop unused
kmap_atomic_to_page").  Let's do it across the whole tree.

Signed-off-by: Nicolas Pitre &lt;nico@linaro.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Removal started in commit 5bbeed12bdc3 ("sparc32: drop unused
kmap_atomic_to_page").  Let's do it across the whole tree.

Signed-off-by: Nicolas Pitre &lt;nico@linaro.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm, page_alloc: distinguish between being unable to sleep, unwilling to sleep and avoiding waking kswapd</title>
<updated>2015-11-07T01:50:42+00:00</updated>
<author>
<name>Mel Gorman</name>
<email>mgorman@techsingularity.net</email>
</author>
<published>2015-11-07T00:28:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=d0164adc89f6bb374d304ffcc375c6d2652fe67d'/>
<id>d0164adc89f6bb374d304ffcc375c6d2652fe67d</id>
<content type='text'>
__GFP_WAIT has been used to identify atomic context in callers that hold
spinlocks or are in interrupts.  They are expected to be high priority and
have access one of two watermarks lower than "min" which can be referred
to as the "atomic reserve".  __GFP_HIGH users get access to the first
lower watermark and can be called the "high priority reserve".

Over time, callers had a requirement to not block when fallback options
were available.  Some have abused __GFP_WAIT leading to a situation where
an optimisitic allocation with a fallback option can access atomic
reserves.

This patch uses __GFP_ATOMIC to identify callers that are truely atomic,
cannot sleep and have no alternative.  High priority users continue to use
__GFP_HIGH.  __GFP_DIRECT_RECLAIM identifies callers that can sleep and
are willing to enter direct reclaim.  __GFP_KSWAPD_RECLAIM to identify
callers that want to wake kswapd for background reclaim.  __GFP_WAIT is
redefined as a caller that is willing to enter direct reclaim and wake
kswapd for background reclaim.

This patch then converts a number of sites

o __GFP_ATOMIC is used by callers that are high priority and have memory
  pools for those requests. GFP_ATOMIC uses this flag.

o Callers that have a limited mempool to guarantee forward progress clear
  __GFP_DIRECT_RECLAIM but keep __GFP_KSWAPD_RECLAIM. bio allocations fall
  into this category where kswapd will still be woken but atomic reserves
  are not used as there is a one-entry mempool to guarantee progress.

o Callers that are checking if they are non-blocking should use the
  helper gfpflags_allow_blocking() where possible. This is because
  checking for __GFP_WAIT as was done historically now can trigger false
  positives. Some exceptions like dm-crypt.c exist where the code intent
  is clearer if __GFP_DIRECT_RECLAIM is used instead of the helper due to
  flag manipulations.

o Callers that built their own GFP flags instead of starting with GFP_KERNEL
  and friends now also need to specify __GFP_KSWAPD_RECLAIM.

The first key hazard to watch out for is callers that removed __GFP_WAIT
and was depending on access to atomic reserves for inconspicuous reasons.
In some cases it may be appropriate for them to use __GFP_HIGH.

The second key hazard is callers that assembled their own combination of
GFP flags instead of starting with something like GFP_KERNEL.  They may
now wish to specify __GFP_KSWAPD_RECLAIM.  It's almost certainly harmless
if it's missed in most cases as other activity will wake kswapd.

Signed-off-by: Mel Gorman &lt;mgorman@techsingularity.net&gt;
Acked-by: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Acked-by: Michal Hocko &lt;mhocko@suse.com&gt;
Acked-by: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Cc: Christoph Lameter &lt;cl@linux.com&gt;
Cc: David Rientjes &lt;rientjes@google.com&gt;
Cc: Vitaly Wool &lt;vitalywool@gmail.com&gt;
Cc: Rik van Riel &lt;riel@redhat.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
__GFP_WAIT has been used to identify atomic context in callers that hold
spinlocks or are in interrupts.  They are expected to be high priority and
have access one of two watermarks lower than "min" which can be referred
to as the "atomic reserve".  __GFP_HIGH users get access to the first
lower watermark and can be called the "high priority reserve".

Over time, callers had a requirement to not block when fallback options
were available.  Some have abused __GFP_WAIT leading to a situation where
an optimisitic allocation with a fallback option can access atomic
reserves.

This patch uses __GFP_ATOMIC to identify callers that are truely atomic,
cannot sleep and have no alternative.  High priority users continue to use
__GFP_HIGH.  __GFP_DIRECT_RECLAIM identifies callers that can sleep and
are willing to enter direct reclaim.  __GFP_KSWAPD_RECLAIM to identify
callers that want to wake kswapd for background reclaim.  __GFP_WAIT is
redefined as a caller that is willing to enter direct reclaim and wake
kswapd for background reclaim.

This patch then converts a number of sites

o __GFP_ATOMIC is used by callers that are high priority and have memory
  pools for those requests. GFP_ATOMIC uses this flag.

o Callers that have a limited mempool to guarantee forward progress clear
  __GFP_DIRECT_RECLAIM but keep __GFP_KSWAPD_RECLAIM. bio allocations fall
  into this category where kswapd will still be woken but atomic reserves
  are not used as there is a one-entry mempool to guarantee progress.

o Callers that are checking if they are non-blocking should use the
  helper gfpflags_allow_blocking() where possible. This is because
  checking for __GFP_WAIT as was done historically now can trigger false
  positives. Some exceptions like dm-crypt.c exist where the code intent
  is clearer if __GFP_DIRECT_RECLAIM is used instead of the helper due to
  flag manipulations.

o Callers that built their own GFP flags instead of starting with GFP_KERNEL
  and friends now also need to specify __GFP_KSWAPD_RECLAIM.

The first key hazard to watch out for is callers that removed __GFP_WAIT
and was depending on access to atomic reserves for inconspicuous reasons.
In some cases it may be appropriate for them to use __GFP_HIGH.

The second key hazard is callers that assembled their own combination of
GFP flags instead of starting with something like GFP_KERNEL.  They may
now wish to specify __GFP_KSWAPD_RECLAIM.  It's almost certainly harmless
if it's missed in most cases as other activity will wake kswapd.

Signed-off-by: Mel Gorman &lt;mgorman@techsingularity.net&gt;
Acked-by: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Acked-by: Michal Hocko &lt;mhocko@suse.com&gt;
Acked-by: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Cc: Christoph Lameter &lt;cl@linux.com&gt;
Cc: David Rientjes &lt;rientjes@google.com&gt;
Cc: Vitaly Wool &lt;vitalywool@gmail.com&gt;
Cc: Rik van Riel &lt;riel@redhat.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>uaccess: reimplement probe_kernel_address() using probe_kernel_read()</title>
<updated>2015-11-06T03:34:48+00:00</updated>
<author>
<name>Andrew Morton</name>
<email>akpm@linux-foundation.org</email>
</author>
<published>2015-11-06T02:46:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=0ab32b6f1b88444524e52429fab334ff96683a3f'/>
<id>0ab32b6f1b88444524e52429fab334ff96683a3f</id>
<content type='text'>
probe_kernel_address() is basically the same as the (later added)
probe_kernel_read().

The return value on EFAULT is a bit different: probe_kernel_address()
returns number-of-bytes-not-copied whereas probe_kernel_read() returns
-EFAULT.  All callers have been checked, none cared.

probe_kernel_read() can be overridden by the architecture whereas
probe_kernel_address() cannot.  parisc, blackfin and um do this, to insert
additional checking.  Hence this patch possibly fixes obscure bugs,
although there are only two probe_kernel_address() callsites outside
arch/.

My first attempt involved removing probe_kernel_address() entirely and
converting all callsites to use probe_kernel_read() directly, but that got
tiresome.

This patch shrinks mm/slab_common.o by 218 bytes.  For a single
probe_kernel_address() callsite.

Cc: Steven Miao &lt;realmz6@gmail.com&gt;
Cc: Jeff Dike &lt;jdike@addtoit.com&gt;
Cc: Richard Weinberger &lt;richard@nod.at&gt;
Cc: "James E.J. Bottomley" &lt;jejb@parisc-linux.org&gt;
Cc: Helge Deller &lt;deller@gmx.de&gt;
Cc: Ingo Molnar &lt;mingo@elte.hu&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
probe_kernel_address() is basically the same as the (later added)
probe_kernel_read().

The return value on EFAULT is a bit different: probe_kernel_address()
returns number-of-bytes-not-copied whereas probe_kernel_read() returns
-EFAULT.  All callers have been checked, none cared.

probe_kernel_read() can be overridden by the architecture whereas
probe_kernel_address() cannot.  parisc, blackfin and um do this, to insert
additional checking.  Hence this patch possibly fixes obscure bugs,
although there are only two probe_kernel_address() callsites outside
arch/.

My first attempt involved removing probe_kernel_address() entirely and
converting all callsites to use probe_kernel_read() directly, but that got
tiresome.

This patch shrinks mm/slab_common.o by 218 bytes.  For a single
probe_kernel_address() callsite.

Cc: Steven Miao &lt;realmz6@gmail.com&gt;
Cc: Jeff Dike &lt;jdike@addtoit.com&gt;
Cc: Richard Weinberger &lt;richard@nod.at&gt;
Cc: "James E.J. Bottomley" &lt;jejb@parisc-linux.org&gt;
Cc: Helge Deller &lt;deller@gmx.de&gt;
Cc: Ingo Molnar &lt;mingo@elte.hu&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branches 'fixes' and 'misc' into for-next</title>
<updated>2015-10-29T15:21:30+00:00</updated>
<author>
<name>Russell King</name>
<email>rmk+kernel@arm.linux.org.uk</email>
</author>
<published>2015-10-29T15:21:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=116ef0fcc9268a876c8d1bbf77d8fa80111fa526'/>
<id>116ef0fcc9268a876c8d1bbf77d8fa80111fa526</id>
<content type='text'>
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
</pre>
</div>
</content>
</entry>
</feed>
