<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/drivers/gpu/drm, branch v4.19-rc1</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>Merge branch 'ida-4.19' of git://git.infradead.org/users/willy/linux-dax</title>
<updated>2018-08-26T18:48:42+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2018-08-26T18:48:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=aba16dc5cf9318b4e0fe92f8261779cd9f1d2d77'/>
<id>aba16dc5cf9318b4e0fe92f8261779cd9f1d2d77</id>
<content type='text'>
Pull IDA updates from Matthew Wilcox:
 "A better IDA API:

      id = ida_alloc(ida, GFP_xxx);
      ida_free(ida, id);

  rather than the cumbersome ida_simple_get(), ida_simple_remove().

  The new IDA API is similar to ida_simple_get() but better named.  The
  internal restructuring of the IDA code removes the bitmap
  preallocation nonsense.

  I hope the net -200 lines of code is convincing"

* 'ida-4.19' of git://git.infradead.org/users/willy/linux-dax: (29 commits)
  ida: Change ida_get_new_above to return the id
  ida: Remove old API
  test_ida: check_ida_destroy and check_ida_alloc
  test_ida: Convert check_ida_conv to new API
  test_ida: Move ida_check_max
  test_ida: Move ida_check_leaf
  idr-test: Convert ida_check_nomem to new API
  ida: Start new test_ida module
  target/iscsi: Allocate session IDs from an IDA
  iscsi target: fix session creation failure handling
  drm/vmwgfx: Convert to new IDA API
  dmaengine: Convert to new IDA API
  ppc: Convert vas ID allocation to new IDA API
  media: Convert entity ID allocation to new IDA API
  ppc: Convert mmu context allocation to new IDA API
  Convert net_namespace to new IDA API
  cb710: Convert to new IDA API
  rsxx: Convert to new IDA API
  osd: Convert to new IDA API
  sd: Convert to new IDA API
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull IDA updates from Matthew Wilcox:
 "A better IDA API:

      id = ida_alloc(ida, GFP_xxx);
      ida_free(ida, id);

  rather than the cumbersome ida_simple_get(), ida_simple_remove().

  The new IDA API is similar to ida_simple_get() but better named.  The
  internal restructuring of the IDA code removes the bitmap
  preallocation nonsense.

  I hope the net -200 lines of code is convincing"

* 'ida-4.19' of git://git.infradead.org/users/willy/linux-dax: (29 commits)
  ida: Change ida_get_new_above to return the id
  ida: Remove old API
  test_ida: check_ida_destroy and check_ida_alloc
  test_ida: Convert check_ida_conv to new API
  test_ida: Move ida_check_max
  test_ida: Move ida_check_leaf
  idr-test: Convert ida_check_nomem to new API
  ida: Start new test_ida module
  target/iscsi: Allocate session IDs from an IDA
  iscsi target: fix session creation failure handling
  drm/vmwgfx: Convert to new IDA API
  dmaengine: Convert to new IDA API
  ppc: Convert vas ID allocation to new IDA API
  media: Convert entity ID allocation to new IDA API
  ppc: Convert mmu context allocation to new IDA API
  Convert net_namespace to new IDA API
  cb710: Convert to new IDA API
  rsxx: Convert to new IDA API
  osd: Convert to new IDA API
  sd: Convert to new IDA API
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'drm-next-2018-08-24' of git://anongit.freedesktop.org/drm/drm</title>
<updated>2018-08-24T16:22:54+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2018-08-24T16:22:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=5e8704ac1cfa9fceef94fcc457e18613b1589b34'/>
<id>5e8704ac1cfa9fceef94fcc457e18613b1589b34</id>
<content type='text'>
Pull drm fixes from Dave Airlie:
 "Just a couple of fixes"

  One MAINTAINERS address change, two panels fixes, and set of amdgpu
  fixes (build fixes, display fixes and some others)"

* tag 'drm-next-2018-08-24' of git://anongit.freedesktop.org/drm/drm:
  drm/edid: Add 6 bpc quirk for SDC panel in Lenovo B50-80
  drm/amd/display: Don't build DCN1 when kcov is enabled
  Revert "drm/amdgpu/display: Replace CONFIG_DRM_AMD_DC_DCN1_0 with CONFIG_X86"
  drm/amdgpu/display: disable eDP fast boot optimization on DCE8
  drm/amdgpu: fix amdgpu_amdkfd_remove_eviction_fence v3
  drm/amdgpu: fix incorrect use of drm_file-&gt;pid
  drm/amdgpu: fix incorrect use of fcheck
  drm/powerplay: enable dpm under pass-through
  drm/amdgpu: access register without KIQ
  drm/amdgpu: set correct base for THM/NBIF/MP1 IP
  drm/amd/display: fix dentist did ranges
  drm/amd/display: make dp_ss_off optional
  drm/amd/display: fix dp_ss_control vbios flag parsing
  drm/amd/display: Do not retain link settings
  MAINTAINERS: drm-misc: Change seanpaul's email address
  drm/panel: simple: tv123wam: Add unprepare delay
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull drm fixes from Dave Airlie:
 "Just a couple of fixes"

  One MAINTAINERS address change, two panels fixes, and set of amdgpu
  fixes (build fixes, display fixes and some others)"

* tag 'drm-next-2018-08-24' of git://anongit.freedesktop.org/drm/drm:
  drm/edid: Add 6 bpc quirk for SDC panel in Lenovo B50-80
  drm/amd/display: Don't build DCN1 when kcov is enabled
  Revert "drm/amdgpu/display: Replace CONFIG_DRM_AMD_DC_DCN1_0 with CONFIG_X86"
  drm/amdgpu/display: disable eDP fast boot optimization on DCE8
  drm/amdgpu: fix amdgpu_amdkfd_remove_eviction_fence v3
  drm/amdgpu: fix incorrect use of drm_file-&gt;pid
  drm/amdgpu: fix incorrect use of fcheck
  drm/powerplay: enable dpm under pass-through
  drm/amdgpu: access register without KIQ
  drm/amdgpu: set correct base for THM/NBIF/MP1 IP
  drm/amd/display: fix dentist did ranges
  drm/amd/display: make dp_ss_off optional
  drm/amd/display: fix dp_ss_control vbios flag parsing
  drm/amd/display: Do not retain link settings
  MAINTAINERS: drm-misc: Change seanpaul's email address
  drm/panel: simple: tv123wam: Add unprepare delay
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'drm-misc-next-fixes-2018-08-23-1' of git://anongit.freedesktop.org/drm/drm-misc into drm-next</title>
<updated>2018-08-24T03:41:03+00:00</updated>
<author>
<name>Dave Airlie</name>
<email>airlied@redhat.com</email>
</author>
<published>2018-08-24T03:40:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=3e20e97c2d55fb18e4b06d16478edc757483b7db'/>
<id>3e20e97c2d55fb18e4b06d16478edc757483b7db</id>
<content type='text'>
- Add quirk to Lenovo B50-80 to use 6 bpc instead of 8 (Feng)

Signed-off-by: Dave Airlie &lt;airlied@redhat.com&gt;
From: Sean Paul &lt;sean@poorly.run&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20180823205434.GA137644@art_vandelay
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
- Add quirk to Lenovo B50-80 to use 6 bpc instead of 8 (Feng)

Signed-off-by: Dave Airlie &lt;airlied@redhat.com&gt;
From: Sean Paul &lt;sean@poorly.run&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20180823205434.GA137644@art_vandelay
</pre>
</div>
</content>
</entry>
<entry>
<title>drivers/gpu/drm/gma500/: change return type to vm_fault_t</title>
<updated>2018-08-24T01:48:43+00:00</updated>
<author>
<name>Souptick Joarder</name>
<email>jrdr.linux@gmail.com</email>
</author>
<published>2018-08-24T00:01:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=0edf68137541a58984cc3a35a193558057f035cb'/>
<id>0edf68137541a58984cc3a35a193558057f035cb</id>
<content type='text'>
Use new return type vm_fault_t for fault handler.  For now, this is just
documenting that the function returns a VM_FAULT value rather than an
errno.  Once all instances are converted, vm_fault_t will become a
distinct type.

Ref-&gt; 1c8f422059ae ("mm: change return type to vm_fault_t")

Previously vm_insert_{pfn,mixed} returns err which driver mapped into
VM_FAULT_* type.  The new function vmf_insert_{pfn,mixed} will replace
this inefficiency by returning VM_FAULT_* type.

vmf_error() is the newly introduce inline function in 4.17-rc6.

Link: http://lkml.kernel.org/r/20180713154541.GA3345@jordon-HP-15-Notebook-PC
Signed-off-by: Souptick Joarder &lt;jrdr.linux@gmail.com&gt;
Reviewed-by: Matthew Wilcox &lt;mawilcox@microsoft.com&gt;
Cc: David Airlie &lt;airlied@linux.ie&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Cc: Patrik Jakobsson &lt;patrik.r.jakobsson@gmail.com&gt;
Cc: Matthew Wilcox &lt;willy@infradead.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>
Use new return type vm_fault_t for fault handler.  For now, this is just
documenting that the function returns a VM_FAULT value rather than an
errno.  Once all instances are converted, vm_fault_t will become a
distinct type.

Ref-&gt; 1c8f422059ae ("mm: change return type to vm_fault_t")

Previously vm_insert_{pfn,mixed} returns err which driver mapped into
VM_FAULT_* type.  The new function vmf_insert_{pfn,mixed} will replace
this inefficiency by returning VM_FAULT_* type.

vmf_error() is the newly introduce inline function in 4.17-rc6.

Link: http://lkml.kernel.org/r/20180713154541.GA3345@jordon-HP-15-Notebook-PC
Signed-off-by: Souptick Joarder &lt;jrdr.linux@gmail.com&gt;
Reviewed-by: Matthew Wilcox &lt;mawilcox@microsoft.com&gt;
Cc: David Airlie &lt;airlied@linux.ie&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Cc: Patrik Jakobsson &lt;patrik.r.jakobsson@gmail.com&gt;
Cc: Matthew Wilcox &lt;willy@infradead.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>drm/edid: Add 6 bpc quirk for SDC panel in Lenovo B50-80</title>
<updated>2018-08-23T08:25:39+00:00</updated>
<author>
<name>Kai-Heng Feng</name>
<email>kai.heng.feng@canonical.com</email>
</author>
<published>2018-08-23T05:53:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=25da75043f8690fd083878447c91f289dfb63b87'/>
<id>25da75043f8690fd083878447c91f289dfb63b87</id>
<content type='text'>
Another panel that reports "DFP 1.x compliant TMDS" but it supports 6bpc
instead of 8 bpc.

Apply 6 bpc quirk for the panel to fix it.

BugLink: https://bugs.launchpad.net/bugs/1788308
Cc: &lt;stable@vger.kernel.org&gt; # v4.8+
Signed-off-by: Kai-Heng Feng &lt;kai.heng.feng@canonical.com&gt;
Signed-off-by: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20180823055332.7723-1-kai.heng.feng@canonical.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Another panel that reports "DFP 1.x compliant TMDS" but it supports 6bpc
instead of 8 bpc.

Apply 6 bpc quirk for the panel to fix it.

BugLink: https://bugs.launchpad.net/bugs/1788308
Cc: &lt;stable@vger.kernel.org&gt; # v4.8+
Signed-off-by: Kai-Heng Feng &lt;kai.heng.feng@canonical.com&gt;
Signed-off-by: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20180823055332.7723-1-kai.heng.feng@canonical.com
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'drm-next-4.19' of git://people.freedesktop.org/~agd5f/linux into drm-next</title>
<updated>2018-08-23T01:24:54+00:00</updated>
<author>
<name>Dave Airlie</name>
<email>airlied@redhat.com</email>
</author>
<published>2018-08-23T01:24:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=8f13b60756a1e5ddc9aa8c6b14807264b6833e5b'/>
<id>8f13b60756a1e5ddc9aa8c6b14807264b6833e5b</id>
<content type='text'>
Fixes for 4.19:
- Fix build when KCOV is enabled
- Misc display fixes
- A couple of SR-IOV fixes
- Fence fixes for eviction handling for KFD
- Misc other fixes

Signed-off-by: Dave Airlie &lt;airlied@redhat.com&gt;
From: Alex Deucher &lt;alexdeucher@gmail.com&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20180822203813.2733-1-alexander.deucher@amd.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Fixes for 4.19:
- Fix build when KCOV is enabled
- Misc display fixes
- A couple of SR-IOV fixes
- Fence fixes for eviction handling for KFD
- Misc other fixes

Signed-off-by: Dave Airlie &lt;airlied@redhat.com&gt;
From: Alex Deucher &lt;alexdeucher@gmail.com&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20180822203813.2733-1-alexander.deucher@amd.com
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'drm-misc-next-fixes-2018-08-22' of git://anongit.freedesktop.org/drm/drm-misc into drm-next</title>
<updated>2018-08-23T01:23:46+00:00</updated>
<author>
<name>Dave Airlie</name>
<email>airlied@redhat.com</email>
</author>
<published>2018-08-23T01:23:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=4d1608eebcb2191b10ac3aa4ca743a38ac05e100'/>
<id>4d1608eebcb2191b10ac3aa4ca743a38ac05e100</id>
<content type='text'>
- Add an unprepare delay to the tv123wam panel (Sean)
- Update seanpaul's email in MAINTAINERS (Sean)

Signed-off-by: Dave Airlie &lt;airlied@redhat.com&gt;
From: Sean Paul &lt;sean@poorly.run&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20180822193850.GA214158@art_vandelay
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
- Add an unprepare delay to the tv123wam panel (Sean)
- Update seanpaul's email in MAINTAINERS (Sean)

Signed-off-by: Dave Airlie &lt;airlied@redhat.com&gt;
From: Sean Paul &lt;sean@poorly.run&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20180822193850.GA214158@art_vandelay
</pre>
</div>
</content>
</entry>
<entry>
<title>include/linux/compiler*.h: make compiler-*.h mutually exclusive</title>
<updated>2018-08-23T00:31:34+00:00</updated>
<author>
<name>Nick Desaulniers</name>
<email>ndesaulniers@google.com</email>
</author>
<published>2018-08-22T23:37:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=815f0ddb346c196018d4d8f8f55c12b83da1de3f'/>
<id>815f0ddb346c196018d4d8f8f55c12b83da1de3f</id>
<content type='text'>
Commit cafa0010cd51 ("Raise the minimum required gcc version to 4.6")
recently exposed a brittle part of the build for supporting non-gcc
compilers.

Both Clang and ICC define __GNUC__, __GNUC_MINOR__, and
__GNUC_PATCHLEVEL__ for quick compatibility with code bases that haven't
added compiler specific checks for __clang__ or __INTEL_COMPILER.

This is brittle, as they happened to get compatibility by posing as a
certain version of GCC.  This broke when upgrading the minimal version
of GCC required to build the kernel, to a version above what ICC and
Clang claim to be.

Rather than always including compiler-gcc.h then undefining or
redefining macros in compiler-intel.h or compiler-clang.h, let's
separate out the compiler specific macro definitions into mutually
exclusive headers, do more proper compiler detection, and keep shared
definitions in compiler_types.h.

Fixes: cafa0010cd51 ("Raise the minimum required gcc version to 4.6")
Reported-by: Masahiro Yamada &lt;yamada.masahiro@socionext.com&gt;
Suggested-by: Eli Friedman &lt;efriedma@codeaurora.org&gt;
Suggested-by: Joe Perches &lt;joe@perches.com&gt;
Signed-off-by: Nick Desaulniers &lt;ndesaulniers@google.com&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>
Commit cafa0010cd51 ("Raise the minimum required gcc version to 4.6")
recently exposed a brittle part of the build for supporting non-gcc
compilers.

Both Clang and ICC define __GNUC__, __GNUC_MINOR__, and
__GNUC_PATCHLEVEL__ for quick compatibility with code bases that haven't
added compiler specific checks for __clang__ or __INTEL_COMPILER.

This is brittle, as they happened to get compatibility by posing as a
certain version of GCC.  This broke when upgrading the minimal version
of GCC required to build the kernel, to a version above what ICC and
Clang claim to be.

Rather than always including compiler-gcc.h then undefining or
redefining macros in compiler-intel.h or compiler-clang.h, let's
separate out the compiler specific macro definitions into mutually
exclusive headers, do more proper compiler detection, and keep shared
definitions in compiler_types.h.

Fixes: cafa0010cd51 ("Raise the minimum required gcc version to 4.6")
Reported-by: Masahiro Yamada &lt;yamada.masahiro@socionext.com&gt;
Suggested-by: Eli Friedman &lt;efriedma@codeaurora.org&gt;
Suggested-by: Joe Perches &lt;joe@perches.com&gt;
Signed-off-by: Nick Desaulniers &lt;ndesaulniers@google.com&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm, oom: distinguish blockable mode for mmu notifiers</title>
<updated>2018-08-22T17:52:44+00:00</updated>
<author>
<name>Michal Hocko</name>
<email>mhocko@suse.com</email>
</author>
<published>2018-08-22T04:52:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=93065ac753e4443840a057bfef4be71ec766fde9'/>
<id>93065ac753e4443840a057bfef4be71ec766fde9</id>
<content type='text'>
There are several blockable mmu notifiers which might sleep in
mmu_notifier_invalidate_range_start and that is a problem for the
oom_reaper because it needs to guarantee a forward progress so it cannot
depend on any sleepable locks.

Currently we simply back off and mark an oom victim with blockable mmu
notifiers as done after a short sleep.  That can result in selecting a new
oom victim prematurely because the previous one still hasn't torn its
memory down yet.

We can do much better though.  Even if mmu notifiers use sleepable locks
there is no reason to automatically assume those locks are held.  Moreover
majority of notifiers only care about a portion of the address space and
there is absolutely zero reason to fail when we are unmapping an unrelated
range.  Many notifiers do really block and wait for HW which is harder to
handle and we have to bail out though.

This patch handles the low hanging fruit.
__mmu_notifier_invalidate_range_start gets a blockable flag and callbacks
are not allowed to sleep if the flag is set to false.  This is achieved by
using trylock instead of the sleepable lock for most callbacks and
continue as long as we do not block down the call chain.

I think we can improve that even further because there is a common pattern
to do a range lookup first and then do something about that.  The first
part can be done without a sleeping lock in most cases AFAICS.

The oom_reaper end then simply retries if there is at least one notifier
which couldn't make any progress in !blockable mode.  A retry loop is
already implemented to wait for the mmap_sem and this is basically the
same thing.

The simplest way for driver developers to test this code path is to wrap
userspace code which uses these notifiers into a memcg and set the hard
limit to hit the oom.  This can be done e.g.  after the test faults in all
the mmu notifier managed memory and set the hard limit to something really
small.  Then we are looking for a proper process tear down.

[akpm@linux-foundation.org: coding style fixes]
[akpm@linux-foundation.org: minor code simplification]
Link: http://lkml.kernel.org/r/20180716115058.5559-1-mhocko@kernel.org
Signed-off-by: Michal Hocko &lt;mhocko@suse.com&gt;
Acked-by: Christian König &lt;christian.koenig@amd.com&gt; # AMD notifiers
Acked-by: Leon Romanovsky &lt;leonro@mellanox.com&gt; # mlx and umem_odp
Reported-by: David Rientjes &lt;rientjes@google.com&gt;
Cc: "David (ChunMing) Zhou" &lt;David1.Zhou@amd.com&gt;
Cc: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
Cc: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Cc: David Airlie &lt;airlied@linux.ie&gt;
Cc: Jani Nikula &lt;jani.nikula@linux.intel.com&gt;
Cc: Joonas Lahtinen &lt;joonas.lahtinen@linux.intel.com&gt;
Cc: Rodrigo Vivi &lt;rodrigo.vivi@intel.com&gt;
Cc: Doug Ledford &lt;dledford@redhat.com&gt;
Cc: Jason Gunthorpe &lt;jgg@ziepe.ca&gt;
Cc: Mike Marciniszyn &lt;mike.marciniszyn@intel.com&gt;
Cc: Dennis Dalessandro &lt;dennis.dalessandro@intel.com&gt;
Cc: Sudeep Dutt &lt;sudeep.dutt@intel.com&gt;
Cc: Ashutosh Dixit &lt;ashutosh.dixit@intel.com&gt;
Cc: Dimitri Sivanich &lt;sivanich@sgi.com&gt;
Cc: Boris Ostrovsky &lt;boris.ostrovsky@oracle.com&gt;
Cc: Juergen Gross &lt;jgross@suse.com&gt;
Cc: "Jérôme Glisse" &lt;jglisse@redhat.com&gt;
Cc: Andrea Arcangeli &lt;aarcange@redhat.com&gt;
Cc: Felix Kuehling &lt;felix.kuehling@amd.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>
There are several blockable mmu notifiers which might sleep in
mmu_notifier_invalidate_range_start and that is a problem for the
oom_reaper because it needs to guarantee a forward progress so it cannot
depend on any sleepable locks.

Currently we simply back off and mark an oom victim with blockable mmu
notifiers as done after a short sleep.  That can result in selecting a new
oom victim prematurely because the previous one still hasn't torn its
memory down yet.

We can do much better though.  Even if mmu notifiers use sleepable locks
there is no reason to automatically assume those locks are held.  Moreover
majority of notifiers only care about a portion of the address space and
there is absolutely zero reason to fail when we are unmapping an unrelated
range.  Many notifiers do really block and wait for HW which is harder to
handle and we have to bail out though.

This patch handles the low hanging fruit.
__mmu_notifier_invalidate_range_start gets a blockable flag and callbacks
are not allowed to sleep if the flag is set to false.  This is achieved by
using trylock instead of the sleepable lock for most callbacks and
continue as long as we do not block down the call chain.

I think we can improve that even further because there is a common pattern
to do a range lookup first and then do something about that.  The first
part can be done without a sleeping lock in most cases AFAICS.

The oom_reaper end then simply retries if there is at least one notifier
which couldn't make any progress in !blockable mode.  A retry loop is
already implemented to wait for the mmap_sem and this is basically the
same thing.

The simplest way for driver developers to test this code path is to wrap
userspace code which uses these notifiers into a memcg and set the hard
limit to hit the oom.  This can be done e.g.  after the test faults in all
the mmu notifier managed memory and set the hard limit to something really
small.  Then we are looking for a proper process tear down.

[akpm@linux-foundation.org: coding style fixes]
[akpm@linux-foundation.org: minor code simplification]
Link: http://lkml.kernel.org/r/20180716115058.5559-1-mhocko@kernel.org
Signed-off-by: Michal Hocko &lt;mhocko@suse.com&gt;
Acked-by: Christian König &lt;christian.koenig@amd.com&gt; # AMD notifiers
Acked-by: Leon Romanovsky &lt;leonro@mellanox.com&gt; # mlx and umem_odp
Reported-by: David Rientjes &lt;rientjes@google.com&gt;
Cc: "David (ChunMing) Zhou" &lt;David1.Zhou@amd.com&gt;
Cc: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
Cc: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Cc: David Airlie &lt;airlied@linux.ie&gt;
Cc: Jani Nikula &lt;jani.nikula@linux.intel.com&gt;
Cc: Joonas Lahtinen &lt;joonas.lahtinen@linux.intel.com&gt;
Cc: Rodrigo Vivi &lt;rodrigo.vivi@intel.com&gt;
Cc: Doug Ledford &lt;dledford@redhat.com&gt;
Cc: Jason Gunthorpe &lt;jgg@ziepe.ca&gt;
Cc: Mike Marciniszyn &lt;mike.marciniszyn@intel.com&gt;
Cc: Dennis Dalessandro &lt;dennis.dalessandro@intel.com&gt;
Cc: Sudeep Dutt &lt;sudeep.dutt@intel.com&gt;
Cc: Ashutosh Dixit &lt;ashutosh.dixit@intel.com&gt;
Cc: Dimitri Sivanich &lt;sivanich@sgi.com&gt;
Cc: Boris Ostrovsky &lt;boris.ostrovsky@oracle.com&gt;
Cc: Juergen Gross &lt;jgross@suse.com&gt;
Cc: "Jérôme Glisse" &lt;jglisse@redhat.com&gt;
Cc: Andrea Arcangeli &lt;aarcange@redhat.com&gt;
Cc: Felix Kuehling &lt;felix.kuehling@amd.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>drm/vmwgfx: Convert to new IDA API</title>
<updated>2018-08-22T03:54:19+00:00</updated>
<author>
<name>Matthew Wilcox</name>
<email>willy@infradead.org</email>
</author>
<published>2018-06-18T20:00:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=4eb085e42fdee0314a89cd12bbd7ad67313d50dd'/>
<id>4eb085e42fdee0314a89cd12bbd7ad67313d50dd</id>
<content type='text'>
Reorder allocation to avoid an awkward lock/unlock/lock sequence.
Simpler code due to being able to use ida_alloc_max(), even if we can't
eliminate the driver's spinlock.

Signed-off-by: Matthew Wilcox &lt;willy@infradead.org&gt;
Reviewed-by: Sinclair Yeh &lt;syeh@vmware.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Reorder allocation to avoid an awkward lock/unlock/lock sequence.
Simpler code due to being able to use ida_alloc_max(), even if we can't
eliminate the driver's spinlock.

Signed-off-by: Matthew Wilcox &lt;willy@infradead.org&gt;
Reviewed-by: Sinclair Yeh &lt;syeh@vmware.com&gt;
</pre>
</div>
</content>
</entry>
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