<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/kernel/cgroup, branch v6.14-rc2</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>Merge tag 'drm-next-2025-01-17' of https://gitlab.freedesktop.org/drm/kernel</title>
<updated>2025-01-22T00:09:47+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2025-01-22T00:09:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=96c84703f1cf6ea43617f9565166681cd71df104'/>
<id>96c84703f1cf6ea43617f9565166681cd71df104</id>
<content type='text'>
Pull drm updates from Dave Airlie:
 "There are two external interactions of note, the msm tree pull in some
  opp tree, hopefully the opp tree arrives from the same git tree
  however it normally does.

  There is also a new cgroup controller for device memory, that is used
  by drm, so is merging through my tree. This will hopefully help open
  up gpu cgroup usage a bit more and move us forward.

  There is a new accelerator driver for the AMD XDNA Ryzen AI NPUs.

  Then the usual xe/amdgpu/i915/msm leaders and lots of changes and
  refactors across the board:

  core:
   - device memory cgroup controller added
   - Remove driver date from drm_driver
   - Add drm_printer based hex dumper
   - drm memory stats docs update
   - scheduler documentation improvements

  new driver:
   - amdxdna - Ryzen AI NPU support

  connector:
   - add a mutex to protect ELD
   - make connector setup two-step

  panels:
   - Introduce backlight quirks infrastructure
   - New panels: KDB KD116N2130B12, Tianma TM070JDHG34-00,
   - Multi-Inno Technology MI1010Z1T-1CP11

  bridge:
   - ti-sn65dsi83: Add ti,lvds-vod-swing optional properties
   - Provide default implementation of atomic_check for HDMI bridges
   - it605: HDCP improvements, MCCS Support

  xe:
   - make OA buffer size configurable
   - GuC capture fixes
   - add ufence and g2h flushes
   - restore system memory GGTT mappings
   - ioctl fixes
   - SRIOV PF scheduling priority
   - allow fault injection
   - lots of improvements/refactors
   - Enable GuC's WA_DUAL_QUEUE for newer platforms
   - IRQ related fixes and improvements

  i915:
   - More accurate engine busyness metrics with GuC submission
   - Ensure partial BO segment offset never exceeds allowed max
   - Flush GuC CT receive tasklet during reset preparation
   - Some DG2 refactor to fix DG2 bugs when operating with certain CPUs
   - Fix DG1 power gate sequence
   - Enabling uncompressed 128b/132b UHBR SST
   - Handle hdmi connector init failures, and no HDMI/DP cases
   - More robust engine resets on Haswell and older

  i915/xe display:
   - HDCP fixes for Xe3Lpd
   - New GSC FW ARL-H/ARL-U
   - support 3 VDSC engines 12 slices
   - MBUS joining sanitisation
   - reconcile i915/xe display power mgmt
   - Xe3Lpd fixes
   - UHBR rates for Thunderbolt

  amdgpu:
   - DRM panic support
   - track BO memory stats at runtime
   - Fix max surface handling in DC
   - Cleaner shader support for gfx10.3 dGPUs
   - fix drm buddy trim handling
   - SDMA engine reset updates
   - Fix doorbell ttm cleanup
   - RAS updates
   - ISP updates
   - SDMA queue reset support
   - Rework DPM powergating interfaces
   - Documentation updates and cleanups
   - DCN 3.5 updates
   - Use a pm notifier to more gracefully handle VRAM eviction on
     suspend or hibernate
   - Add debugfs interfaces for forcing scheduling to specific engine
     instances
   - GG 9.5 updates
   - IH 4.4 updates
   - Make missing optional firmware less noisy
   - PSP 13.x updates
   - SMU 13.x updates
   - VCN 5.x updates
   - JPEG 5.x updates
   - GC 12.x updates
   - DC FAMS updates

  amdkfd:
   - GG 9.5 updates
   - Logging improvements
   - Shader debugger fixes
   - Trap handler cleanup
   - Cleanup includes
   - Eviction fence wq fix

  msm:
   - MDSS:
      - properly described UBWC registers
      - added SM6150 (aka QCS615) support
   - DPU:
      - added SM6150 (aka QCS615) support
      - enabled wide planes if virtual planes are enabled (by using two
        SSPPs for a single plane)
      - added CWB hardware blocks support
   - DSI:
      - added SM6150 (aka QCS615) support
   - GPU:
      - Print GMU core fw version
      - GMU bandwidth voting for a740 and a750
      - Expose uche trap base via uapi
      - UAPI error reporting

  rcar-du:
   - Add r8a779h0 Support

  ivpu:
   - Fix qemu crash when using passthrough

  nouveau:
   - expose GSP-RM logging buffers via debugfs

  panfrost:
   - Add MT8188 Mali-G57 MC3 support

  rockchip:
   - Gamma LUT support

  hisilicon:
   - new HIBMC support

  virtio-gpu:
   - convert to helpers
   - add prime support for scanout buffers

  v3d:
   - Add DRM_IOCTL_V3D_PERFMON_SET_GLOBAL

  vc4:
   - Add support for BCM2712

  vkms:
   - line-per-line compositing algorithm to improve performance

  zynqmp:
   - Add DP audio support

  mediatek:
   - dp: Add sdp path reset
   - dp: Support flexible length of DP calibration data

  etnaviv:
   - add fdinfo memory support
   - add explicit reset handling"

* tag 'drm-next-2025-01-17' of https://gitlab.freedesktop.org/drm/kernel: (1070 commits)
  drm/bridge: fix documentation for the hdmi_audio_prepare() callback
  doc/cgroup: Fix title underline length
  drm/doc: Include new drm-compute documentation
  cgroup/dmem: Fix parameters documentation
  cgroup/dmem: Select PAGE_COUNTER
  kernel/cgroup: Remove the unused variable climit
  drm/display: hdmi: Do not read EDID on disconnected connectors
  drm/tests: hdmi: Add connector disablement test
  drm/connector: hdmi: Do atomic check when necessary
  drm/amd/display: 3.2.316
  drm/amd/display: avoid reset DTBCLK at clock init
  drm/amd/display: improve dpia pre-train
  drm/amd/display: Apply DML21 Patches
  drm/amd/display: Use HW lock mgr for PSR1
  drm/amd/display: Revised for Replay Pseudo vblank control
  drm/amd/display: Add a new flag for replay low hz
  drm/amd/display: Remove unused read_ono_state function from Hwss module
  drm/amd/display: Do not elevate mem_type change to full update
  drm/amd/display: Do not wait for PSR disable on vbl enable
  drm/amd/display: Remove unnecessary eDP power down
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull drm updates from Dave Airlie:
 "There are two external interactions of note, the msm tree pull in some
  opp tree, hopefully the opp tree arrives from the same git tree
  however it normally does.

  There is also a new cgroup controller for device memory, that is used
  by drm, so is merging through my tree. This will hopefully help open
  up gpu cgroup usage a bit more and move us forward.

  There is a new accelerator driver for the AMD XDNA Ryzen AI NPUs.

  Then the usual xe/amdgpu/i915/msm leaders and lots of changes and
  refactors across the board:

  core:
   - device memory cgroup controller added
   - Remove driver date from drm_driver
   - Add drm_printer based hex dumper
   - drm memory stats docs update
   - scheduler documentation improvements

  new driver:
   - amdxdna - Ryzen AI NPU support

  connector:
   - add a mutex to protect ELD
   - make connector setup two-step

  panels:
   - Introduce backlight quirks infrastructure
   - New panels: KDB KD116N2130B12, Tianma TM070JDHG34-00,
   - Multi-Inno Technology MI1010Z1T-1CP11

  bridge:
   - ti-sn65dsi83: Add ti,lvds-vod-swing optional properties
   - Provide default implementation of atomic_check for HDMI bridges
   - it605: HDCP improvements, MCCS Support

  xe:
   - make OA buffer size configurable
   - GuC capture fixes
   - add ufence and g2h flushes
   - restore system memory GGTT mappings
   - ioctl fixes
   - SRIOV PF scheduling priority
   - allow fault injection
   - lots of improvements/refactors
   - Enable GuC's WA_DUAL_QUEUE for newer platforms
   - IRQ related fixes and improvements

  i915:
   - More accurate engine busyness metrics with GuC submission
   - Ensure partial BO segment offset never exceeds allowed max
   - Flush GuC CT receive tasklet during reset preparation
   - Some DG2 refactor to fix DG2 bugs when operating with certain CPUs
   - Fix DG1 power gate sequence
   - Enabling uncompressed 128b/132b UHBR SST
   - Handle hdmi connector init failures, and no HDMI/DP cases
   - More robust engine resets on Haswell and older

  i915/xe display:
   - HDCP fixes for Xe3Lpd
   - New GSC FW ARL-H/ARL-U
   - support 3 VDSC engines 12 slices
   - MBUS joining sanitisation
   - reconcile i915/xe display power mgmt
   - Xe3Lpd fixes
   - UHBR rates for Thunderbolt

  amdgpu:
   - DRM panic support
   - track BO memory stats at runtime
   - Fix max surface handling in DC
   - Cleaner shader support for gfx10.3 dGPUs
   - fix drm buddy trim handling
   - SDMA engine reset updates
   - Fix doorbell ttm cleanup
   - RAS updates
   - ISP updates
   - SDMA queue reset support
   - Rework DPM powergating interfaces
   - Documentation updates and cleanups
   - DCN 3.5 updates
   - Use a pm notifier to more gracefully handle VRAM eviction on
     suspend or hibernate
   - Add debugfs interfaces for forcing scheduling to specific engine
     instances
   - GG 9.5 updates
   - IH 4.4 updates
   - Make missing optional firmware less noisy
   - PSP 13.x updates
   - SMU 13.x updates
   - VCN 5.x updates
   - JPEG 5.x updates
   - GC 12.x updates
   - DC FAMS updates

  amdkfd:
   - GG 9.5 updates
   - Logging improvements
   - Shader debugger fixes
   - Trap handler cleanup
   - Cleanup includes
   - Eviction fence wq fix

  msm:
   - MDSS:
      - properly described UBWC registers
      - added SM6150 (aka QCS615) support
   - DPU:
      - added SM6150 (aka QCS615) support
      - enabled wide planes if virtual planes are enabled (by using two
        SSPPs for a single plane)
      - added CWB hardware blocks support
   - DSI:
      - added SM6150 (aka QCS615) support
   - GPU:
      - Print GMU core fw version
      - GMU bandwidth voting for a740 and a750
      - Expose uche trap base via uapi
      - UAPI error reporting

  rcar-du:
   - Add r8a779h0 Support

  ivpu:
   - Fix qemu crash when using passthrough

  nouveau:
   - expose GSP-RM logging buffers via debugfs

  panfrost:
   - Add MT8188 Mali-G57 MC3 support

  rockchip:
   - Gamma LUT support

  hisilicon:
   - new HIBMC support

  virtio-gpu:
   - convert to helpers
   - add prime support for scanout buffers

  v3d:
   - Add DRM_IOCTL_V3D_PERFMON_SET_GLOBAL

  vc4:
   - Add support for BCM2712

  vkms:
   - line-per-line compositing algorithm to improve performance

  zynqmp:
   - Add DP audio support

  mediatek:
   - dp: Add sdp path reset
   - dp: Support flexible length of DP calibration data

  etnaviv:
   - add fdinfo memory support
   - add explicit reset handling"

* tag 'drm-next-2025-01-17' of https://gitlab.freedesktop.org/drm/kernel: (1070 commits)
  drm/bridge: fix documentation for the hdmi_audio_prepare() callback
  doc/cgroup: Fix title underline length
  drm/doc: Include new drm-compute documentation
  cgroup/dmem: Fix parameters documentation
  cgroup/dmem: Select PAGE_COUNTER
  kernel/cgroup: Remove the unused variable climit
  drm/display: hdmi: Do not read EDID on disconnected connectors
  drm/tests: hdmi: Add connector disablement test
  drm/connector: hdmi: Do atomic check when necessary
  drm/amd/display: 3.2.316
  drm/amd/display: avoid reset DTBCLK at clock init
  drm/amd/display: improve dpia pre-train
  drm/amd/display: Apply DML21 Patches
  drm/amd/display: Use HW lock mgr for PSR1
  drm/amd/display: Revised for Replay Pseudo vblank control
  drm/amd/display: Add a new flag for replay low hz
  drm/amd/display: Remove unused read_ono_state function from Hwss module
  drm/amd/display: Do not elevate mem_type change to full update
  drm/amd/display: Do not wait for PSR disable on vbl enable
  drm/amd/display: Remove unnecessary eDP power down
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>cgroup/dmem: Fix parameters documentation</title>
<updated>2025-01-15T08:45:24+00:00</updated>
<author>
<name>Maxime Ripard</name>
<email>mripard@kernel.org</email>
</author>
<published>2025-01-13T09:26:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=feb85972b82c9747ebb0843f91e4c1e023b47f3d'/>
<id>feb85972b82c9747ebb0843f91e4c1e023b47f3d</id>
<content type='text'>
During the dmem cgroup development, the parameters to the
dmem_cgroup_state_evict_valuable() and dmem_cgroup_try_charge() were
changed, but the documentation wasn't adjusted accordingly.

This results in a documentation build warning. Adjust the documentation
to reflect what the final functions parameters are.

Fixes: b168ed458dde ("kernel/cgroup: Add "dmem" memory accounting cgroup")
Reported-by: Stephen Rothwell &lt;sfr@canb.auug.org.au&gt;
Closes: https://lore.kernel.org/r/20250113160334.1f09f881@canb.auug.org.au/
Acked-by: Tejun Heo &lt;tj@kernel.org&gt;
Reviewed-by: Simona Vetter &lt;simona.vetter@ffwll.ch&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20250113092608.1349287-2-mripard@kernel.org
Signed-off-by: Maxime Ripard &lt;mripard@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
During the dmem cgroup development, the parameters to the
dmem_cgroup_state_evict_valuable() and dmem_cgroup_try_charge() were
changed, but the documentation wasn't adjusted accordingly.

This results in a documentation build warning. Adjust the documentation
to reflect what the final functions parameters are.

Fixes: b168ed458dde ("kernel/cgroup: Add "dmem" memory accounting cgroup")
Reported-by: Stephen Rothwell &lt;sfr@canb.auug.org.au&gt;
Closes: https://lore.kernel.org/r/20250113160334.1f09f881@canb.auug.org.au/
Acked-by: Tejun Heo &lt;tj@kernel.org&gt;
Reviewed-by: Simona Vetter &lt;simona.vetter@ffwll.ch&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20250113092608.1349287-2-mripard@kernel.org
Signed-off-by: Maxime Ripard &lt;mripard@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>kernel/cgroup: Remove the unused variable climit</title>
<updated>2025-01-15T08:39:26+00:00</updated>
<author>
<name>Jiapeng Chong</name>
<email>jiapeng.chong@linux.alibaba.com</email>
</author>
<published>2025-01-14T06:28:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=8f52fd7a7de6097089f73bd7dad7c558ea9a8a3f'/>
<id>8f52fd7a7de6097089f73bd7dad7c558ea9a8a3f</id>
<content type='text'>
Variable climit is not effectively used, so delete it.

kernel/cgroup/dmem.c:302:23: warning: variable ‘climit’ set but not used.

Reported-by: Abaci Robot &lt;abaci@linux.alibaba.com&gt;
Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=13512
Signed-off-by: Jiapeng Chong &lt;jiapeng.chong@linux.alibaba.com&gt;
Acked-by: Tejun Heo &lt;tj@kernel.org&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20250114062804.5092-1-jiapeng.chong@linux.alibaba.com
Signed-off-by: Maxime Ripard &lt;mripard@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Variable climit is not effectively used, so delete it.

kernel/cgroup/dmem.c:302:23: warning: variable ‘climit’ set but not used.

Reported-by: Abaci Robot &lt;abaci@linux.alibaba.com&gt;
Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=13512
Signed-off-by: Jiapeng Chong &lt;jiapeng.chong@linux.alibaba.com&gt;
Acked-by: Tejun Heo &lt;tj@kernel.org&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20250114062804.5092-1-jiapeng.chong@linux.alibaba.com
Signed-off-by: Maxime Ripard &lt;mripard@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>cgroup/cpuset: remove kernfs active break</title>
<updated>2025-01-09T01:54:39+00:00</updated>
<author>
<name>Chen Ridong</name>
<email>chenridong@huawei.com</email>
</author>
<published>2025-01-06T08:19:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=3cb97a927fffe443e1e7e8eddbfebfdb062e86ed'/>
<id>3cb97a927fffe443e1e7e8eddbfebfdb062e86ed</id>
<content type='text'>
A warning was found:

WARNING: CPU: 10 PID: 3486953 at fs/kernfs/file.c:828
CPU: 10 PID: 3486953 Comm: rmdir Kdump: loaded Tainted: G
RIP: 0010:kernfs_should_drain_open_files+0x1a1/0x1b0
RSP: 0018:ffff8881107ef9e0 EFLAGS: 00010202
RAX: 0000000080000002 RBX: ffff888154738c00 RCX: dffffc0000000000
RDX: 0000000000000007 RSI: 0000000000000004 RDI: ffff888154738c04
RBP: ffff888154738c04 R08: ffffffffaf27fa15 R09: ffffed102a8e7180
R10: ffff888154738c07 R11: 0000000000000000 R12: ffff888154738c08
R13: ffff888750f8c000 R14: ffff888750f8c0e8 R15: ffff888154738ca0
FS:  00007f84cd0be740(0000) GS:ffff8887ddc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555f9fbe00c8 CR3: 0000000153eec001 CR4: 0000000000370ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 kernfs_drain+0x15e/0x2f0
 __kernfs_remove+0x165/0x300
 kernfs_remove_by_name_ns+0x7b/0xc0
 cgroup_rm_file+0x154/0x1c0
 cgroup_addrm_files+0x1c2/0x1f0
 css_clear_dir+0x77/0x110
 kill_css+0x4c/0x1b0
 cgroup_destroy_locked+0x194/0x380
 cgroup_rmdir+0x2a/0x140

It can be explained by:
rmdir 				echo 1 &gt; cpuset.cpus
				kernfs_fop_write_iter // active=0
cgroup_rm_file
kernfs_remove_by_name_ns	kernfs_get_active // active=1
__kernfs_remove					  // active=0x80000002
kernfs_drain			cpuset_write_resmask
wait_event
//waiting (active == 0x80000001)
				kernfs_break_active_protection
				// active = 0x80000001
// continue
				kernfs_unbreak_active_protection
				// active = 0x80000002
...
kernfs_should_drain_open_files
// warning occurs
				kernfs_put_active

This warning is caused by 'kernfs_break_active_protection' when it is
writing to cpuset.cpus, and the cgroup is removed concurrently.

The commit 3a5a6d0c2b03 ("cpuset: don't nest cgroup_mutex inside
get_online_cpus()") made cpuset_hotplug_workfn asynchronous, This change
involves calling flush_work(), which can create a multiple processes
circular locking dependency that involve cgroup_mutex, potentially leading
to a deadlock. To avoid deadlock. the commit 76bb5ab8f6e3 ("cpuset: break
kernfs active protection in cpuset_write_resmask()") added
'kernfs_break_active_protection' in the cpuset_write_resmask. This could
lead to this warning.

After the commit 2125c0034c5d ("cgroup/cpuset: Make cpuset hotplug
processing synchronous"), the cpuset_write_resmask no longer needs to
wait the hotplug to finish, which means that concurrent hotplug and cpuset
operations are no longer possible. Therefore, the deadlock doesn't exist
anymore and it does not have to 'break active protection' now. To fix this
warning, just remove kernfs_break_active_protection operation in the
'cpuset_write_resmask'.

Fixes: bdb2fd7fc56e ("kernfs: Skip kernfs_drain_open_files() more aggressively")
Fixes: 76bb5ab8f6e3 ("cpuset: break kernfs active protection in cpuset_write_resmask()")
Reported-by: Ji Fa &lt;jifa@huawei.com&gt;
Signed-off-by: Chen Ridong &lt;chenridong@huawei.com&gt;
Acked-by: Waiman Long &lt;longman@redhat.com&gt;
Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
A warning was found:

WARNING: CPU: 10 PID: 3486953 at fs/kernfs/file.c:828
CPU: 10 PID: 3486953 Comm: rmdir Kdump: loaded Tainted: G
RIP: 0010:kernfs_should_drain_open_files+0x1a1/0x1b0
RSP: 0018:ffff8881107ef9e0 EFLAGS: 00010202
RAX: 0000000080000002 RBX: ffff888154738c00 RCX: dffffc0000000000
RDX: 0000000000000007 RSI: 0000000000000004 RDI: ffff888154738c04
RBP: ffff888154738c04 R08: ffffffffaf27fa15 R09: ffffed102a8e7180
R10: ffff888154738c07 R11: 0000000000000000 R12: ffff888154738c08
R13: ffff888750f8c000 R14: ffff888750f8c0e8 R15: ffff888154738ca0
FS:  00007f84cd0be740(0000) GS:ffff8887ddc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555f9fbe00c8 CR3: 0000000153eec001 CR4: 0000000000370ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 kernfs_drain+0x15e/0x2f0
 __kernfs_remove+0x165/0x300
 kernfs_remove_by_name_ns+0x7b/0xc0
 cgroup_rm_file+0x154/0x1c0
 cgroup_addrm_files+0x1c2/0x1f0
 css_clear_dir+0x77/0x110
 kill_css+0x4c/0x1b0
 cgroup_destroy_locked+0x194/0x380
 cgroup_rmdir+0x2a/0x140

It can be explained by:
rmdir 				echo 1 &gt; cpuset.cpus
				kernfs_fop_write_iter // active=0
cgroup_rm_file
kernfs_remove_by_name_ns	kernfs_get_active // active=1
__kernfs_remove					  // active=0x80000002
kernfs_drain			cpuset_write_resmask
wait_event
//waiting (active == 0x80000001)
				kernfs_break_active_protection
				// active = 0x80000001
// continue
				kernfs_unbreak_active_protection
				// active = 0x80000002
...
kernfs_should_drain_open_files
// warning occurs
				kernfs_put_active

This warning is caused by 'kernfs_break_active_protection' when it is
writing to cpuset.cpus, and the cgroup is removed concurrently.

The commit 3a5a6d0c2b03 ("cpuset: don't nest cgroup_mutex inside
get_online_cpus()") made cpuset_hotplug_workfn asynchronous, This change
involves calling flush_work(), which can create a multiple processes
circular locking dependency that involve cgroup_mutex, potentially leading
to a deadlock. To avoid deadlock. the commit 76bb5ab8f6e3 ("cpuset: break
kernfs active protection in cpuset_write_resmask()") added
'kernfs_break_active_protection' in the cpuset_write_resmask. This could
lead to this warning.

After the commit 2125c0034c5d ("cgroup/cpuset: Make cpuset hotplug
processing synchronous"), the cpuset_write_resmask no longer needs to
wait the hotplug to finish, which means that concurrent hotplug and cpuset
operations are no longer possible. Therefore, the deadlock doesn't exist
anymore and it does not have to 'break active protection' now. To fix this
warning, just remove kernfs_break_active_protection operation in the
'cpuset_write_resmask'.

Fixes: bdb2fd7fc56e ("kernfs: Skip kernfs_drain_open_files() more aggressively")
Fixes: 76bb5ab8f6e3 ("cpuset: break kernfs active protection in cpuset_write_resmask()")
Reported-by: Ji Fa &lt;jifa@huawei.com&gt;
Signed-off-by: Chen Ridong &lt;chenridong@huawei.com&gt;
Acked-by: Waiman Long &lt;longman@redhat.com&gt;
Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>kernel/cgroup: Add "dmem" memory accounting cgroup</title>
<updated>2025-01-06T16:24:38+00:00</updated>
<author>
<name>Maarten Lankhorst</name>
<email>dev@lankhorst.se</email>
</author>
<published>2024-12-04T14:31:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=b168ed458ddecc176f3b9a1f4bcd83d7a4541c14'/>
<id>b168ed458ddecc176f3b9a1f4bcd83d7a4541c14</id>
<content type='text'>
This code is based on the RDMA and misc cgroup initially, but now
uses page_counter. It uses the same min/low/max semantics as the memory
cgroup as a result.

There's a small mismatch as TTM uses u64, and page_counter long pages.
In practice it's not a problem. 32-bits systems don't really come with
&gt;=4GB cards and as long as we're consistently wrong with units, it's
fine. The device page size may not be in the same units as kernel page
size, and each region might also have a different page size (VRAM vs GART
for example).

The interface is simple:
- Call dmem_cgroup_register_region()
- Use dmem_cgroup_try_charge to check if you can allocate a chunk of memory,
  use dmem_cgroup__uncharge when freeing it. This may return an error code,
  or -EAGAIN when the cgroup limit is reached. In that case a reference
  to the limiting pool is returned.
- The limiting cs can be used as compare function for
  dmem_cgroup_state_evict_valuable.
- After having evicted enough, drop reference to limiting cs with
  dmem_cgroup_pool_state_put.

This API allows you to limit device resources with cgroups.
You can see the supported cards in /sys/fs/cgroup/dmem.capacity
You need to echo +dmem to cgroup.subtree_control, and then you can
partition device memory.

Co-developed-by: Friedrich Vock &lt;friedrich.vock@gmx.de&gt;
Signed-off-by: Friedrich Vock &lt;friedrich.vock@gmx.de&gt;
Co-developed-by: Maxime Ripard &lt;mripard@kernel.org&gt;
Signed-off-by: Maarten Lankhorst &lt;dev@lankhorst.se&gt;
Acked-by: Tejun Heo &lt;tj@kernel.org&gt;
Link: https://lore.kernel.org/r/20241204143112.1250983-1-dev@lankhorst.se
Signed-off-by: Maxime Ripard &lt;mripard@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This code is based on the RDMA and misc cgroup initially, but now
uses page_counter. It uses the same min/low/max semantics as the memory
cgroup as a result.

There's a small mismatch as TTM uses u64, and page_counter long pages.
In practice it's not a problem. 32-bits systems don't really come with
&gt;=4GB cards and as long as we're consistently wrong with units, it's
fine. The device page size may not be in the same units as kernel page
size, and each region might also have a different page size (VRAM vs GART
for example).

The interface is simple:
- Call dmem_cgroup_register_region()
- Use dmem_cgroup_try_charge to check if you can allocate a chunk of memory,
  use dmem_cgroup__uncharge when freeing it. This may return an error code,
  or -EAGAIN when the cgroup limit is reached. In that case a reference
  to the limiting pool is returned.
- The limiting cs can be used as compare function for
  dmem_cgroup_state_evict_valuable.
- After having evicted enough, drop reference to limiting cs with
  dmem_cgroup_pool_state_put.

This API allows you to limit device resources with cgroups.
You can see the supported cards in /sys/fs/cgroup/dmem.capacity
You need to echo +dmem to cgroup.subtree_control, and then you can
partition device memory.

Co-developed-by: Friedrich Vock &lt;friedrich.vock@gmx.de&gt;
Signed-off-by: Friedrich Vock &lt;friedrich.vock@gmx.de&gt;
Co-developed-by: Maxime Ripard &lt;mripard@kernel.org&gt;
Signed-off-by: Maarten Lankhorst &lt;dev@lankhorst.se&gt;
Acked-by: Tejun Heo &lt;tj@kernel.org&gt;
Link: https://lore.kernel.org/r/20241204143112.1250983-1-dev@lankhorst.se
Signed-off-by: Maxime Ripard &lt;mripard@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>cgroup/cpuset: Prevent leakage of isolated CPUs into sched domains</title>
<updated>2024-12-11T15:45:52+00:00</updated>
<author>
<name>Waiman Long</name>
<email>longman@redhat.com</email>
</author>
<published>2024-12-05T19:51:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=9b496a8bbed9cc292b0dfd796f38ec58b6d0375f'/>
<id>9b496a8bbed9cc292b0dfd796f38ec58b6d0375f</id>
<content type='text'>
Isolated CPUs are not allowed to be used in a non-isolated partition.
The only exception is the top cpuset which is allowed to contain boot
time isolated CPUs.

Commit ccac8e8de99c ("cgroup/cpuset: Fix remote root partition creation
problem") introduces a simplified scheme of including only partition
roots in sched domain generation. However, it does not properly account
for this exception case. This can result in leakage of isolated CPUs
into a sched domain.

Fix it by making sure that isolated CPUs are excluded from the top
cpuset before generating sched domains.

Also update the way the boot time isolated CPUs are handled in
test_cpuset_prs.sh to make sure that those isolated CPUs are really
isolated instead of just skipping them in the tests.

Fixes: ccac8e8de99c ("cgroup/cpuset: Fix remote root partition creation problem")
Signed-off-by: Waiman Long &lt;longman@redhat.com&gt;
Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Isolated CPUs are not allowed to be used in a non-isolated partition.
The only exception is the top cpuset which is allowed to contain boot
time isolated CPUs.

Commit ccac8e8de99c ("cgroup/cpuset: Fix remote root partition creation
problem") introduces a simplified scheme of including only partition
roots in sched domain generation. However, it does not properly account
for this exception case. This can result in leakage of isolated CPUs
into a sched domain.

Fix it by making sure that isolated CPUs are excluded from the top
cpuset before generating sched domains.

Also update the way the boot time isolated CPUs are handled in
test_cpuset_prs.sh to make sure that those isolated CPUs are really
isolated instead of just skipping them in the tests.

Fixes: ccac8e8de99c ("cgroup/cpuset: Fix remote root partition creation problem")
Signed-off-by: Waiman Long &lt;longman@redhat.com&gt;
Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>cgroup/cpuset: Remove stale text</title>
<updated>2024-12-11T06:38:41+00:00</updated>
<author>
<name>Costa Shulyupin</name>
<email>costa.shul@redhat.com</email>
</author>
<published>2024-12-04T11:04:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=eb1dd15fb26d9ad85204f444ef03f29f9049eb1e'/>
<id>eb1dd15fb26d9ad85204f444ef03f29f9049eb1e</id>
<content type='text'>
Task's cpuset pointer was removed by
commit 8793d854edbc ("Task Control Groups: make cpusets a client of cgroups")

Paragraph "The task_lock() exception ...." was removed by
commit 2df167a300d7 ("cgroups: update comments in cpuset.c")

Remove stale text:

 We also require taking task_lock() when dereferencing a
 task's cpuset pointer. See "The task_lock() exception", at the end of this
 comment.

 Accessing a task's cpuset should be done in accordance with the
 guidelines for accessing subsystem state in kernel/cgroup.c

and reformat.

Co-developed-by: Michal Koutný &lt;mkoutny@suse.com&gt;
Co-developed-by: Waiman Long &lt;longman@redhat.com&gt;
Signed-off-by: Costa Shulyupin &lt;costa.shul@redhat.com&gt;
Acked-by: Waiman Long &lt;longman@redhat.com&gt;
Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Task's cpuset pointer was removed by
commit 8793d854edbc ("Task Control Groups: make cpusets a client of cgroups")

Paragraph "The task_lock() exception ...." was removed by
commit 2df167a300d7 ("cgroups: update comments in cpuset.c")

Remove stale text:

 We also require taking task_lock() when dereferencing a
 task's cpuset pointer. See "The task_lock() exception", at the end of this
 comment.

 Accessing a task's cpuset should be done in accordance with the
 guidelines for accessing subsystem state in kernel/cgroup.c

and reformat.

Co-developed-by: Michal Koutný &lt;mkoutny@suse.com&gt;
Co-developed-by: Waiman Long &lt;longman@redhat.com&gt;
Signed-off-by: Costa Shulyupin &lt;costa.shul@redhat.com&gt;
Acked-by: Waiman Long &lt;longman@redhat.com&gt;
Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'cgroup-for-6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup</title>
<updated>2024-11-20T17:54:49+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-11-20T17:54:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=7586d5276515a54656bc46530b32e10913c44b1f'/>
<id>7586d5276515a54656bc46530b32e10913c44b1f</id>
<content type='text'>
Pull cgroup updates from Tejun Heo:

 - cpu.stat now also shows niced CPU time

 - Freezer and cpuset optimizations

 - Other misc changes

* tag 'cgroup-for-6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup/cpuset: Disable cpuset_cpumask_can_shrink() test if not load balancing
  cgroup/cpuset: Further optimize code if CONFIG_CPUSETS_V1 not set
  cgroup/cpuset: Enforce at most one rebuild_sched_domains_locked() call per operation
  cgroup/cpuset: Revert "Allow suppression of sched domain rebuild in update_cpumasks_hier()"
  MAINTAINERS: remove Zefan Li
  cgroup/freezer: Add cgroup CGRP_FROZEN flag update helper
  cgroup/freezer: Reduce redundant traversal for cgroup_freeze
  cgroup/bpf: only cgroup v2 can be attached by bpf programs
  Revert "cgroup: Fix memory leak caused by missing cgroup_bpf_offline"
  selftests/cgroup: Fix compile error in test_cpu.c
  cgroup/rstat: Selftests for niced CPU statistics
  cgroup/rstat: Tracking cgroup-level niced CPU time
  cgroup/cpuset: Fix spelling errors in file kernel/cgroup/cpuset.c
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull cgroup updates from Tejun Heo:

 - cpu.stat now also shows niced CPU time

 - Freezer and cpuset optimizations

 - Other misc changes

* tag 'cgroup-for-6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup/cpuset: Disable cpuset_cpumask_can_shrink() test if not load balancing
  cgroup/cpuset: Further optimize code if CONFIG_CPUSETS_V1 not set
  cgroup/cpuset: Enforce at most one rebuild_sched_domains_locked() call per operation
  cgroup/cpuset: Revert "Allow suppression of sched domain rebuild in update_cpumasks_hier()"
  MAINTAINERS: remove Zefan Li
  cgroup/freezer: Add cgroup CGRP_FROZEN flag update helper
  cgroup/freezer: Reduce redundant traversal for cgroup_freeze
  cgroup/bpf: only cgroup v2 can be attached by bpf programs
  Revert "cgroup: Fix memory leak caused by missing cgroup_bpf_offline"
  selftests/cgroup: Fix compile error in test_cpu.c
  cgroup/rstat: Selftests for niced CPU statistics
  cgroup/rstat: Tracking cgroup-level niced CPU time
  cgroup/cpuset: Fix spelling errors in file kernel/cgroup/cpuset.c
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'pull-fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs</title>
<updated>2024-11-18T20:24:06+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-11-18T20:24:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=0f25f0e4efaeb68086f7e65c442f2d648b21736f'/>
<id>0f25f0e4efaeb68086f7e65c442f2d648b21736f</id>
<content type='text'>
Pull 'struct fd' class updates from Al Viro:
 "The bulk of struct fd memory safety stuff

  Making sure that struct fd instances are destroyed in the same scope
  where they'd been created, getting rid of reassignments and passing
  them by reference, converting to CLASS(fd{,_pos,_raw}).

  We are getting very close to having the memory safety of that stuff
  trivial to verify"

* tag 'pull-fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (28 commits)
  deal with the last remaing boolean uses of fd_file()
  css_set_fork(): switch to CLASS(fd_raw, ...)
  memcg_write_event_control(): switch to CLASS(fd)
  assorted variants of irqfd setup: convert to CLASS(fd)
  do_pollfd(): convert to CLASS(fd)
  convert do_select()
  convert vfs_dedupe_file_range().
  convert cifs_ioctl_copychunk()
  convert media_request_get_by_fd()
  convert spu_run(2)
  switch spufs_calls_{get,put}() to CLASS() use
  convert cachestat(2)
  convert do_preadv()/do_pwritev()
  fdget(), more trivial conversions
  fdget(), trivial conversions
  privcmd_ioeventfd_assign(): don't open-code eventfd_ctx_fdget()
  o2hb_region_dev_store(): avoid goto around fdget()/fdput()
  introduce "fd_pos" class, convert fdget_pos() users to it.
  fdget_raw() users: switch to CLASS(fd_raw)
  convert vmsplice() to CLASS(fd)
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull 'struct fd' class updates from Al Viro:
 "The bulk of struct fd memory safety stuff

  Making sure that struct fd instances are destroyed in the same scope
  where they'd been created, getting rid of reassignments and passing
  them by reference, converting to CLASS(fd{,_pos,_raw}).

  We are getting very close to having the memory safety of that stuff
  trivial to verify"

* tag 'pull-fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (28 commits)
  deal with the last remaing boolean uses of fd_file()
  css_set_fork(): switch to CLASS(fd_raw, ...)
  memcg_write_event_control(): switch to CLASS(fd)
  assorted variants of irqfd setup: convert to CLASS(fd)
  do_pollfd(): convert to CLASS(fd)
  convert do_select()
  convert vfs_dedupe_file_range().
  convert cifs_ioctl_copychunk()
  convert media_request_get_by_fd()
  convert spu_run(2)
  switch spufs_calls_{get,put}() to CLASS() use
  convert cachestat(2)
  convert do_preadv()/do_pwritev()
  fdget(), more trivial conversions
  fdget(), trivial conversions
  privcmd_ioeventfd_assign(): don't open-code eventfd_ctx_fdget()
  o2hb_region_dev_store(): avoid goto around fdget()/fdput()
  introduce "fd_pos" class, convert fdget_pos() users to it.
  fdget_raw() users: switch to CLASS(fd_raw)
  convert vmsplice() to CLASS(fd)
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>cgroup/cpuset: Disable cpuset_cpumask_can_shrink() test if not load balancing</title>
<updated>2024-11-14T18:44:03+00:00</updated>
<author>
<name>Waiman Long</name>
<email>longman@redhat.com</email>
</author>
<published>2024-11-14T18:19:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=fbfbf86685b3270dc27d1c5d6108532334aaf329'/>
<id>fbfbf86685b3270dc27d1c5d6108532334aaf329</id>
<content type='text'>
With some recent proposed changes [1] in the deadline server code,
it has caused a test failure in test_cpuset_prs.sh when a change
is being made to an isolated partition. This is due to failing
the cpuset_cpumask_can_shrink() check for SCHED_DEADLINE tasks at
validate_change().

This is actually a false positive as the failed test case involves an
isolated partition with load balancing disabled. The deadline check
is not meaningful in this case and the users should know what they
are doing.

Fix this by doing the cpuset_cpumask_can_shrink() check only when loading
balanced is enabled. Also change its arguments to use effective_cpus
for the current cpuset and user_xcpus() as an approiximation for the
target effective_cpus as the real effective_cpus hasn't been fully
computed yet as this early stage.

As the check isn't comprehensive, there may be false positives or
negatives. We may have to revise the code to do a more thorough check
in the future if this becomes a concern.

[1] https://lore.kernel.org/lkml/82be06c1-6d6d-4651-86c9-bcc828cbcb80@redhat.com/T/#t

Signed-off-by: Waiman Long &lt;longman@redhat.com&gt;
Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
With some recent proposed changes [1] in the deadline server code,
it has caused a test failure in test_cpuset_prs.sh when a change
is being made to an isolated partition. This is due to failing
the cpuset_cpumask_can_shrink() check for SCHED_DEADLINE tasks at
validate_change().

This is actually a false positive as the failed test case involves an
isolated partition with load balancing disabled. The deadline check
is not meaningful in this case and the users should know what they
are doing.

Fix this by doing the cpuset_cpumask_can_shrink() check only when loading
balanced is enabled. Also change its arguments to use effective_cpus
for the current cpuset and user_xcpus() as an approiximation for the
target effective_cpus as the real effective_cpus hasn't been fully
computed yet as this early stage.

As the check isn't comprehensive, there may be false positives or
negatives. We may have to revise the code to do a more thorough check
in the future if this becomes a concern.

[1] https://lore.kernel.org/lkml/82be06c1-6d6d-4651-86c9-bcc828cbcb80@redhat.com/T/#t

Signed-off-by: Waiman Long &lt;longman@redhat.com&gt;
Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
