<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/include/linux/cgroup.h, branch v7.3-rc2</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>Merge tag 'drm-next-2026-08-20' of https://gitlab.freedesktop.org/drm/kernel</title>
<updated>2026-08-21T15:41:00+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2026-08-21T15:41:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4e69c1856bfd9ffb7e9d335a25842fa211628929'/>
<id>4e69c1856bfd9ffb7e9d335a25842fa211628929</id>
<content type='text'>
Pull drm updates from Dave Airlie:
 "Highlights:

   - dmemcg eviction support is good for low VRAM things like Steam
     Machine

   - AMD adds gfx6-8 modifier support for older GPUs that enables a
     bunch of wayland stuff

   - i915/xe has some new hw support but also a lot of display
     refactoring

  Everything:

  perf:
   - export perf_allow_ APIs for xe

  udmabuf:
   - remove default size limit of 64MB

  rust:
   - i/o rework (signed tag from driver-core tree)
   - add registration guard and registration data
   - fix unbounded lifetimes in ioctl handler args
   - fix a drm_dev_register race
   - gem_shmem: add DmaResvGuard helper
   - gpuvm: require send/sync for driver data
       - implement send/sync for GpuVaAlloc and GpuVmBo
       - add SmContext lifetime
   - rename dma_handle to dma_address
   - change pci_sriov_get_totalvfs return to unsigned int

  core:
   - create drm_of_get_panel_orientation
   - send per-connector hotplug events
   - add thunderbolt UBHR tunneling support

  connector:
   - add color format property

  dmem:
   - introduce a peak file
   - accept one region per limit
   - add dmemcg support for eviction

  gpusvm:
   - reorg code to give drivers more flexibility

  atomic:
   - add create_state callback and helper
   - add documentation on atomic commit lifetime

  buddy:
   - add per-order free
   - add used block scoreboard
   - fix UAF
   - test buffer clearance on resume
   - add phys_addr-&gt;block helper

  gem:
   - drop DRIVER_GEM_GPUVA flag

  ttm:
   - be more aggressive allocating below protection limit

  sched:
   - add test suite for concurrent job submissions

  hdmi:
   - hook the color format property in helpers

  mipi-dsi:
   - add MIPI_DSI_MODE_DSC_ALL_SLICES_IN_PKT

  bridge:
   - add atomic create callbacks
   - drop atomic reset
   - display-connector: don't autoenable HPD IRQ
   - trigger initial HPD for DP
   - ti-sn65dsi83: remove NO_HFP and NO_HBP mode flags
   - analogix_dp: switch to DP link training helpers

  dp:
   - add support for DSC max delta BPP

  edid:
   - parse panel type from DisplayID 2.x Display Parameters

  sysfb:
   - improve panel, stride, framebuffer size validation

  panel:
   - implement ref counting for struct drm_panel
   - himax-hx83121a: add backlight regulator support
   - novatek-nt36672a: Inline panel init sequences
   - visionox-vtdr6130: enable DSC
   - novatek-nt37801: Use mipi_dsi_*_multi() functions
   - samsung-s6d16d0: Fix prepare error handling
   - support Novatek NT36536 plus DT bindings
   - sofef00: fix backlight updates
   - osd101t2587: use mipi_dsi_*_multi interface
   - panel-edp: adjust timing for AUO displays
   - panel-lvds: support Opto Logic SCX1001511GGC49
   - panel-simple: support Kyocera tcg070wvlq
   - panel-edp: quirks
       - AUO B116XAT04.3, CMN N116BCP-EA2, CSW MNB601LS1-8
       - BOE NV116WH2-M30, BOE NT116WHM-N21, BOE NV116FH1-M31
       - BOE NV116FH1-M30, NV140FHM-N5B, TM156VDXP25
       - BOE NE160QDM-NY1, MB116AS01
   - new:
       - Samsung ATNA40HQ08-0, Anbernic TD4310
       - Chipone ICNA35XX, Ilitek ILI9488
       - Ilitek ILI7807S, Renesas R63419
       - MNE001BS6-2, MNF601BS4-1, Sharp LQ120P1JX51

  virtio:
   - add support for save/restore virtio_gpu_objects
   - abort vq wait on device removal

  amdgpu:
   - add color format DRM property
   - initial compute pipe reset support
   - add GFX 6-8 modifier support
   - initial DCN 6.0.0 support
   - dmemcg eviction support
   - improved boundary checking for bios parsing
   - RAS updates and rework
   - VCN secure submission fixes
   - 8K panel fix
   - Display KUNIT tests
   - parse panel type from DisplayID
   - Align IP discovery to pci device lifetime
   - SOC15 register macro cleanups
   - UVD memory placement fixes
   - GFX9 mode2 reset fixes
   - drop unnecessary BUG/BUG_ON
   - GFX8 soft reset rework
   - enable soft reset on GFX8
   - PSP/SMU 15.0.9 update
   - VI ASPM fix
   - userq fixes
   - amdgpu_vm_get_task_info_pasid lifetime fix
   - DC CACP support
   - change system_unbound_wq with system_dfl_wq
   - Loosen VFCT bios parsing to deal with pci=realloc
   - SI/SMU7 AC/DC switch fix
   - VM fence handling fix
   - GEM close optimisation
   - Apple Studio Display fixes
   - DC FRL fixes

  amdkfd:
   - initial compute pipe reset support
   - allow applications to opt out of sigbus on fatal errors
   - improve CRIU boundary checks
   - MQD handling rework
   - move TBA/TMA from system to device memory
   - avoid topology-lock in kfd_mmap
   - SVM eviction fixes

  radeon:
   - fix unset CONFIG_ACPI build

  i915:
   - Novalake (NVL display version 35) timing generator enabling
   - NVL DC3CO enabling
   - enable UBHR link rates on thunderbolt tunnels
   - Reduce Xe3+ PM demand peak bandwidth
   - enable pipe DMC error interrupts for display 30+
   - add kunit tests for DP link config selection
   - refactor and document DP link recovery
   - i915/xe driver display probe/remove/suspend/resume/shutdown cleanup
     and unification
   - i915/xe display runtime PM unified
   - Break i915 and xe panic dependency on struct intel_framebuffer
   - Streamline Pre/Post-CSC LUT loops
   - drop TGL DC3DO support
   - CDCLK santization
   - fix HDMI scrambling enable
   - fix phys bo pread/pwrite with offset
   - add missing nospec on parallel submit slot
   - fix some NULL derefs

  xe:
   - drop force_execlist module param
   - gate observation streams with perf_allow_cpu
   - skip FORCE_WC and vm_bound check for external dma-bufs
   - dmemcg eviction support
   - remove unused NVL-S GuC
   - TLB invalidation improvements
   - NVL-S updated PCI-IDs and w/a
   - madvise: optimise invalidation path
   - fix infinite gt-reset loop in timeout recovery
   - update TTM device benefical_order
   - wait on external BO kernel fences in exec ioctl
   - add/use more KLV helpers
   - sriov: disable display in admin only PF mode
   - add RAS GPU health indicator
   - optimise TTM populate for DONTNEED BO
   - drop force_probe for NVL-s
   - add debugfs for pcode info

  amdxdna:
   - disable device buffer export

  nova:
   - build nova-core/nova-drm from drivers/gpu
   - export nova-core rust symbols (workaround)
   - GSP boot process consolidation
   - Boot GSP with vGPU enabled
   - TLV firmware image format support
   - Hopper/Blackwell fixes and cleanups
   - I/O projection adoption

  tyr:
   - firmware loading and MCU boot
   - add generic slot manager + MMU
   - GPU VM support ARM64 LPAE page tables
   - add kernel buffer object for internal allocations
   - add parser for Mali CSF
   - add MCU booting

  nouveau:
   - race fixes
   - check instmem iomapping at first use
   - add dmemcg support
   - expose NVDEC channels
   - add scanline position/head state support for GSP

  qxl:
   - convert simple encoder to regular

  ethosu:
   - add perf counter support

  etnaviv:
   - force flush on power register ops

  msm:
   - support DSC configuration with slice_per_pkt &gt; 1

  mxsfb:
   - fix disable sequence

  panthor:
   - support sparse mappings

  rockchip:
   - switch away from simple helpers
   - support YUV background color
   - fix layer config timeout
   - add edp support for rk3576
   - add batch command submission function

  rocket:
   - error handling and NULL ptr deref fixes

  sun4i:
   - switch away from simple helpers

  imagination:
   - mark BXM-4-64 MC1 as support

  host1x:
   - support tegra264

  tegra:
   - add DSI for tegra 20/30

  v3d:
   - reduce PM runtime autosuspend delay
   - scheduler fixes and refactoring
   - deprecate v3d 3.3 and 4.1
   - validate CPU job query boundaries

  hibmc:
   - improve plane format handling
   - switch to gem shmem

  mediatek:
   - cec: correct compat for mt7623-8167?

  exynos:
   - remove simple dependency
   - add error handling to encoder paths
   - take i2c adapter module reference"

* tag 'drm-next-2026-08-20' of https://gitlab.freedesktop.org/drm/kernel: (2074 commits)
  drm/xe/mcr: Take vcs1/vecs1 into account for first media slice
  drm/xe: Fix a bug in pc_adjust_freq_bounds()
  drm/xe: Fix xe_device_probe() failure
  drm/xe/drm_ras: Move has_drm_ras check to drm_ras layer
  drm/xe/ras: Fix boot-time ras error processing
  drm/amd/display: make DC_RUN_WITH_PREEMPTION_ENABLED misuse a build error
  drm/amd/pm: silence uninitialized variable warnings
  drm/amdgpu: skip BOs being torn down during GTT recovery
  drm/amdgpu: Reject UVD message with invalid number of h265 refs
  drm/amdgpu: keep PRT mappings off the vm_bo state lists
  drm/amdgpu: fix nbif 6.3.1 l1 low power not functional
  drm/amd/display: fix BT.2020 YCbCr output CSC matrices for DCE
  drm/amd/display: fix BT.2020 YCbCr limited output CSC matrix
  drm/amdgpu: Implement insert_end for VCE 3
  drm/amdgpu: Fix UVD min buffer sizes
  drm/amdgpu: Fix UVD decode image min size calculation
  drm/amdgpu: Fix UVD dpb min size calculation for H264
  drm/amdgpu: Reject UVD message with dimensions above 4096
  drm/amdgpu: check ASPM on the dGPU host link
  drm/radeon: fix autosuspend cleanup during teardown
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull drm updates from Dave Airlie:
 "Highlights:

   - dmemcg eviction support is good for low VRAM things like Steam
     Machine

   - AMD adds gfx6-8 modifier support for older GPUs that enables a
     bunch of wayland stuff

   - i915/xe has some new hw support but also a lot of display
     refactoring

  Everything:

  perf:
   - export perf_allow_ APIs for xe

  udmabuf:
   - remove default size limit of 64MB

  rust:
   - i/o rework (signed tag from driver-core tree)
   - add registration guard and registration data
   - fix unbounded lifetimes in ioctl handler args
   - fix a drm_dev_register race
   - gem_shmem: add DmaResvGuard helper
   - gpuvm: require send/sync for driver data
       - implement send/sync for GpuVaAlloc and GpuVmBo
       - add SmContext lifetime
   - rename dma_handle to dma_address
   - change pci_sriov_get_totalvfs return to unsigned int

  core:
   - create drm_of_get_panel_orientation
   - send per-connector hotplug events
   - add thunderbolt UBHR tunneling support

  connector:
   - add color format property

  dmem:
   - introduce a peak file
   - accept one region per limit
   - add dmemcg support for eviction

  gpusvm:
   - reorg code to give drivers more flexibility

  atomic:
   - add create_state callback and helper
   - add documentation on atomic commit lifetime

  buddy:
   - add per-order free
   - add used block scoreboard
   - fix UAF
   - test buffer clearance on resume
   - add phys_addr-&gt;block helper

  gem:
   - drop DRIVER_GEM_GPUVA flag

  ttm:
   - be more aggressive allocating below protection limit

  sched:
   - add test suite for concurrent job submissions

  hdmi:
   - hook the color format property in helpers

  mipi-dsi:
   - add MIPI_DSI_MODE_DSC_ALL_SLICES_IN_PKT

  bridge:
   - add atomic create callbacks
   - drop atomic reset
   - display-connector: don't autoenable HPD IRQ
   - trigger initial HPD for DP
   - ti-sn65dsi83: remove NO_HFP and NO_HBP mode flags
   - analogix_dp: switch to DP link training helpers

  dp:
   - add support for DSC max delta BPP

  edid:
   - parse panel type from DisplayID 2.x Display Parameters

  sysfb:
   - improve panel, stride, framebuffer size validation

  panel:
   - implement ref counting for struct drm_panel
   - himax-hx83121a: add backlight regulator support
   - novatek-nt36672a: Inline panel init sequences
   - visionox-vtdr6130: enable DSC
   - novatek-nt37801: Use mipi_dsi_*_multi() functions
   - samsung-s6d16d0: Fix prepare error handling
   - support Novatek NT36536 plus DT bindings
   - sofef00: fix backlight updates
   - osd101t2587: use mipi_dsi_*_multi interface
   - panel-edp: adjust timing for AUO displays
   - panel-lvds: support Opto Logic SCX1001511GGC49
   - panel-simple: support Kyocera tcg070wvlq
   - panel-edp: quirks
       - AUO B116XAT04.3, CMN N116BCP-EA2, CSW MNB601LS1-8
       - BOE NV116WH2-M30, BOE NT116WHM-N21, BOE NV116FH1-M31
       - BOE NV116FH1-M30, NV140FHM-N5B, TM156VDXP25
       - BOE NE160QDM-NY1, MB116AS01
   - new:
       - Samsung ATNA40HQ08-0, Anbernic TD4310
       - Chipone ICNA35XX, Ilitek ILI9488
       - Ilitek ILI7807S, Renesas R63419
       - MNE001BS6-2, MNF601BS4-1, Sharp LQ120P1JX51

  virtio:
   - add support for save/restore virtio_gpu_objects
   - abort vq wait on device removal

  amdgpu:
   - add color format DRM property
   - initial compute pipe reset support
   - add GFX 6-8 modifier support
   - initial DCN 6.0.0 support
   - dmemcg eviction support
   - improved boundary checking for bios parsing
   - RAS updates and rework
   - VCN secure submission fixes
   - 8K panel fix
   - Display KUNIT tests
   - parse panel type from DisplayID
   - Align IP discovery to pci device lifetime
   - SOC15 register macro cleanups
   - UVD memory placement fixes
   - GFX9 mode2 reset fixes
   - drop unnecessary BUG/BUG_ON
   - GFX8 soft reset rework
   - enable soft reset on GFX8
   - PSP/SMU 15.0.9 update
   - VI ASPM fix
   - userq fixes
   - amdgpu_vm_get_task_info_pasid lifetime fix
   - DC CACP support
   - change system_unbound_wq with system_dfl_wq
   - Loosen VFCT bios parsing to deal with pci=realloc
   - SI/SMU7 AC/DC switch fix
   - VM fence handling fix
   - GEM close optimisation
   - Apple Studio Display fixes
   - DC FRL fixes

  amdkfd:
   - initial compute pipe reset support
   - allow applications to opt out of sigbus on fatal errors
   - improve CRIU boundary checks
   - MQD handling rework
   - move TBA/TMA from system to device memory
   - avoid topology-lock in kfd_mmap
   - SVM eviction fixes

  radeon:
   - fix unset CONFIG_ACPI build

  i915:
   - Novalake (NVL display version 35) timing generator enabling
   - NVL DC3CO enabling
   - enable UBHR link rates on thunderbolt tunnels
   - Reduce Xe3+ PM demand peak bandwidth
   - enable pipe DMC error interrupts for display 30+
   - add kunit tests for DP link config selection
   - refactor and document DP link recovery
   - i915/xe driver display probe/remove/suspend/resume/shutdown cleanup
     and unification
   - i915/xe display runtime PM unified
   - Break i915 and xe panic dependency on struct intel_framebuffer
   - Streamline Pre/Post-CSC LUT loops
   - drop TGL DC3DO support
   - CDCLK santization
   - fix HDMI scrambling enable
   - fix phys bo pread/pwrite with offset
   - add missing nospec on parallel submit slot
   - fix some NULL derefs

  xe:
   - drop force_execlist module param
   - gate observation streams with perf_allow_cpu
   - skip FORCE_WC and vm_bound check for external dma-bufs
   - dmemcg eviction support
   - remove unused NVL-S GuC
   - TLB invalidation improvements
   - NVL-S updated PCI-IDs and w/a
   - madvise: optimise invalidation path
   - fix infinite gt-reset loop in timeout recovery
   - update TTM device benefical_order
   - wait on external BO kernel fences in exec ioctl
   - add/use more KLV helpers
   - sriov: disable display in admin only PF mode
   - add RAS GPU health indicator
   - optimise TTM populate for DONTNEED BO
   - drop force_probe for NVL-s
   - add debugfs for pcode info

  amdxdna:
   - disable device buffer export

  nova:
   - build nova-core/nova-drm from drivers/gpu
   - export nova-core rust symbols (workaround)
   - GSP boot process consolidation
   - Boot GSP with vGPU enabled
   - TLV firmware image format support
   - Hopper/Blackwell fixes and cleanups
   - I/O projection adoption

  tyr:
   - firmware loading and MCU boot
   - add generic slot manager + MMU
   - GPU VM support ARM64 LPAE page tables
   - add kernel buffer object for internal allocations
   - add parser for Mali CSF
   - add MCU booting

  nouveau:
   - race fixes
   - check instmem iomapping at first use
   - add dmemcg support
   - expose NVDEC channels
   - add scanline position/head state support for GSP

  qxl:
   - convert simple encoder to regular

  ethosu:
   - add perf counter support

  etnaviv:
   - force flush on power register ops

  msm:
   - support DSC configuration with slice_per_pkt &gt; 1

  mxsfb:
   - fix disable sequence

  panthor:
   - support sparse mappings

  rockchip:
   - switch away from simple helpers
   - support YUV background color
   - fix layer config timeout
   - add edp support for rk3576
   - add batch command submission function

  rocket:
   - error handling and NULL ptr deref fixes

  sun4i:
   - switch away from simple helpers

  imagination:
   - mark BXM-4-64 MC1 as support

  host1x:
   - support tegra264

  tegra:
   - add DSI for tegra 20/30

  v3d:
   - reduce PM runtime autosuspend delay
   - scheduler fixes and refactoring
   - deprecate v3d 3.3 and 4.1
   - validate CPU job query boundaries

  hibmc:
   - improve plane format handling
   - switch to gem shmem

  mediatek:
   - cec: correct compat for mt7623-8167?

  exynos:
   - remove simple dependency
   - add error handling to encoder paths
   - take i2c adapter module reference"

* tag 'drm-next-2026-08-20' of https://gitlab.freedesktop.org/drm/kernel: (2074 commits)
  drm/xe/mcr: Take vcs1/vecs1 into account for first media slice
  drm/xe: Fix a bug in pc_adjust_freq_bounds()
  drm/xe: Fix xe_device_probe() failure
  drm/xe/drm_ras: Move has_drm_ras check to drm_ras layer
  drm/xe/ras: Fix boot-time ras error processing
  drm/amd/display: make DC_RUN_WITH_PREEMPTION_ENABLED misuse a build error
  drm/amd/pm: silence uninitialized variable warnings
  drm/amdgpu: skip BOs being torn down during GTT recovery
  drm/amdgpu: Reject UVD message with invalid number of h265 refs
  drm/amdgpu: keep PRT mappings off the vm_bo state lists
  drm/amdgpu: fix nbif 6.3.1 l1 low power not functional
  drm/amd/display: fix BT.2020 YCbCr output CSC matrices for DCE
  drm/amd/display: fix BT.2020 YCbCr limited output CSC matrix
  drm/amdgpu: Implement insert_end for VCE 3
  drm/amdgpu: Fix UVD min buffer sizes
  drm/amdgpu: Fix UVD decode image min size calculation
  drm/amdgpu: Fix UVD dpb min size calculation for H264
  drm/amdgpu: Reject UVD message with dimensions above 4096
  drm/amdgpu: check ASPM on the dGPU host link
  drm/radeon: fix autosuspend cleanup during teardown
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'sched_ext-for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext</title>
<updated>2026-08-20T18:01:37+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2026-08-20T18:01:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=11260c335ec6071af5543aef73000b28f041c124'/>
<id>11260c335ec6071af5543aef73000b28f041c124</id>
<content type='text'>
Pull sched_ext updates from Tejun Heo:
 "Most of this cycle completes the enqueue-path support for hierarchical
  sub-scheduling, which makes sub-scheduler support feature complete: a
  root BPF scheduler can now hand a cgroup subtree over to a nested
  sub-scheduler together with revocable CPU grants, and the
  sub-scheduler owns all scheduling decisions for its tasks on those
  CPUs.

  Development volume was high and a number of changes plugging holes in
  the new support landed late in the cycle. Also included are core
  scheduling fixes that were completed too late for the v7.2 release and
  are routed through this pull request.

  Sub-scheduler CPU delegation:

   - Parent schedulers now grant and revoke per-CPU capabilities
     (enqueueing, preemption, CPU frequency control) on their children,
     enforced on every path a scheduler can reach a CPU through.
     Previously only dispatching could be delegated; this lets
     sub-schedulers fully schedule their CPUs.

   - Rescue execution: a task whose scheduler doesn't have access to the
     CPUs the task needs to run on starved until the watchdog ejected
     the whole scheduler. The kernel now runs such tasks directly on a
     small bandwidth budget, turning a scheduler-killing failure into
     bounded degradation.

   - Cgroup integration: tasks migrating across a sub-scheduler boundary
     weren't re-homed to the new owner, causing wrong-scheduler
     scheduling and a use-after-free. Sub-schedulers now take over their
     cgroup subtree and receive its cgroup callbacks.

   - Arena objects now cross the kernel/BPF boundary as typed pointer
     arguments, translated transparently by the BPF tree's new arena
     argument support, replacing untyped arguments with manual
     translation.

   - scx_qmap now demonstrates full hierarchical sub-scheduling.

  Other fixes and updates:

   - Robustness improvements: the abort path is now NMI-safe, fixing
     deadlocks when errors are raised from NMI context and making
     hardlockup recovery direct. Reenqueue loops that could monopolize a
     CPU ahead of the watchdog now eject the offending scheduler, and
     stalls are blamed on the scheduler actually responsible.

   - Hardening: BPF-writable arena memory is validated before kernel
     use, and task slice and vtime writes got explicit synchronization
     rules, closing corruption vectors open to buggy or malicious
     schedulers.

   - Core scheduling: sched_ext dispatching can drop the rq lock inside
     the core-wide pick, which let interleaving selections corrupt each
     other's state and hard-hang the machine. The selection now restarts
     when the lock was released. The task ordering callback was also
     invoked with its arguments swapped, and the default ordering is
     updated to work across sub-scheduler boundaries. The fixes are
     marked for stable.

   - Other fixes headed for stable: a task init leak on fork failure
     during enable, tooling compat macros that silently failed to detect
     newer kernels, and a crash on reenqueueing against a destroyed
     dispatch queue.

   - Tooling: scx_pair moves off deprecated callbacks, and the
     deprecated scx_bpf_cpu_rq() kfunc is removed"

* tag 'sched_ext-for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext: (144 commits)
  sched_ext: Drop the dead SCX_DEQ_CORE_SCHED_EXEC test in dequeue_task_scx()
  sched_ext: Make core-sched task ordering hierarchy-aware
  sched_ext: Use runnable_at for the default core-sched task ordering
  sched_ext: Fix inverted ops.core_sched_before() invocation
  sched_ext: Move the config-off sub-cap kfunc stubs into sub.c
  sched_ext: Rename balance-era identifiers to dispatch terms
  sched_ext: Drop the stale keep_prev fixup in dispatch_pick()
  sched_ext: Keep kick_sync waiting on the rq's own CPU
  sched_ext: Make SCHED_CLASS_EXT select GENERIC_ALLOCATOR
  sched_ext/scx_flatcg: Fix cvtime true-up on slice expiry
  sched_ext: Don't BUG_ON a destroyed DSQ in process_deferred_reenq_users
  sched_ext: Fix scx_bpf_dsq_move_to_local___v2 compat detection
  sched_ext: Make scx_bpf_events() read the calling scheduler's counters
  sched_ext: Drop unlocked scx_rq_clock_invalidate() from scx_root_disable()
  selftests/sched_ext: Fix flaky ddsp failure tests on busy systems
  selftests/sched_ext: Make numa idle validation race-free
  sched_ext: Fix scx_bpf_dsq_reenq___compat kfunc extern prototype
  sched_ext/scx_flatcg: expire cached hweights on weight changes
  sched_ext: Fix exit_task leak on fork failure during enable
  sched_ext: fix stale references in doc comments
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull sched_ext updates from Tejun Heo:
 "Most of this cycle completes the enqueue-path support for hierarchical
  sub-scheduling, which makes sub-scheduler support feature complete: a
  root BPF scheduler can now hand a cgroup subtree over to a nested
  sub-scheduler together with revocable CPU grants, and the
  sub-scheduler owns all scheduling decisions for its tasks on those
  CPUs.

  Development volume was high and a number of changes plugging holes in
  the new support landed late in the cycle. Also included are core
  scheduling fixes that were completed too late for the v7.2 release and
  are routed through this pull request.

  Sub-scheduler CPU delegation:

   - Parent schedulers now grant and revoke per-CPU capabilities
     (enqueueing, preemption, CPU frequency control) on their children,
     enforced on every path a scheduler can reach a CPU through.
     Previously only dispatching could be delegated; this lets
     sub-schedulers fully schedule their CPUs.

   - Rescue execution: a task whose scheduler doesn't have access to the
     CPUs the task needs to run on starved until the watchdog ejected
     the whole scheduler. The kernel now runs such tasks directly on a
     small bandwidth budget, turning a scheduler-killing failure into
     bounded degradation.

   - Cgroup integration: tasks migrating across a sub-scheduler boundary
     weren't re-homed to the new owner, causing wrong-scheduler
     scheduling and a use-after-free. Sub-schedulers now take over their
     cgroup subtree and receive its cgroup callbacks.

   - Arena objects now cross the kernel/BPF boundary as typed pointer
     arguments, translated transparently by the BPF tree's new arena
     argument support, replacing untyped arguments with manual
     translation.

   - scx_qmap now demonstrates full hierarchical sub-scheduling.

  Other fixes and updates:

   - Robustness improvements: the abort path is now NMI-safe, fixing
     deadlocks when errors are raised from NMI context and making
     hardlockup recovery direct. Reenqueue loops that could monopolize a
     CPU ahead of the watchdog now eject the offending scheduler, and
     stalls are blamed on the scheduler actually responsible.

   - Hardening: BPF-writable arena memory is validated before kernel
     use, and task slice and vtime writes got explicit synchronization
     rules, closing corruption vectors open to buggy or malicious
     schedulers.

   - Core scheduling: sched_ext dispatching can drop the rq lock inside
     the core-wide pick, which let interleaving selections corrupt each
     other's state and hard-hang the machine. The selection now restarts
     when the lock was released. The task ordering callback was also
     invoked with its arguments swapped, and the default ordering is
     updated to work across sub-scheduler boundaries. The fixes are
     marked for stable.

   - Other fixes headed for stable: a task init leak on fork failure
     during enable, tooling compat macros that silently failed to detect
     newer kernels, and a crash on reenqueueing against a destroyed
     dispatch queue.

   - Tooling: scx_pair moves off deprecated callbacks, and the
     deprecated scx_bpf_cpu_rq() kfunc is removed"

* tag 'sched_ext-for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext: (144 commits)
  sched_ext: Drop the dead SCX_DEQ_CORE_SCHED_EXEC test in dequeue_task_scx()
  sched_ext: Make core-sched task ordering hierarchy-aware
  sched_ext: Use runnable_at for the default core-sched task ordering
  sched_ext: Fix inverted ops.core_sched_before() invocation
  sched_ext: Move the config-off sub-cap kfunc stubs into sub.c
  sched_ext: Rename balance-era identifiers to dispatch terms
  sched_ext: Drop the stale keep_prev fixup in dispatch_pick()
  sched_ext: Keep kick_sync waiting on the rq's own CPU
  sched_ext: Make SCHED_CLASS_EXT select GENERIC_ALLOCATOR
  sched_ext/scx_flatcg: Fix cvtime true-up on slice expiry
  sched_ext: Don't BUG_ON a destroyed DSQ in process_deferred_reenq_users
  sched_ext: Fix scx_bpf_dsq_move_to_local___v2 compat detection
  sched_ext: Make scx_bpf_events() read the calling scheduler's counters
  sched_ext: Drop unlocked scx_rq_clock_invalidate() from scx_root_disable()
  selftests/sched_ext: Fix flaky ddsp failure tests on busy systems
  selftests/sched_ext: Make numa idle validation race-free
  sched_ext: Fix scx_bpf_dsq_reenq___compat kfunc extern prototype
  sched_ext/scx_flatcg: expire cached hweights on weight changes
  sched_ext: Fix exit_task leak on fork failure during enable
  sched_ext: fix stale references in doc comments
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>cgroup,cgroup/dmem: Add (dmem_)cgroup_common_ancestor helper</title>
<updated>2026-08-05T08:34:42+00:00</updated>
<author>
<name>Natalie Vock</name>
<email>natalie.vock@gmx.de</email>
</author>
<published>2026-08-04T08:25:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=34f3e259925382cd87187dd426d3918379c6144e'/>
<id>34f3e259925382cd87187dd426d3918379c6144e</id>
<content type='text'>
This helps to find a common subtree of two resources, which is important
when determining whether it's helpful to evict one resource in favor of
another.

To facilitate this, add a common helper to find the ancestor of two
cgroups using each cgroup's ancestor array.

Tested-by: Thadeu Lima de Souza Cascardo &lt;cascardo@igalia.com&gt;
Reviewed-by: Maarten Lankhorst &lt;dev@lankhorst.se&gt;
Reviewed-by: Timur Kristóf &lt;timur.kristof@gmail.com&gt;
Signed-off-by: Natalie Vock &lt;natalie.vock@gmx.de&gt;
Link: https://patch.msgid.link/20260804-dmemcg-aggressive-protect-v8-2-07af96681bf8@gmx.de
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This helps to find a common subtree of two resources, which is important
when determining whether it's helpful to evict one resource in favor of
another.

To facilitate this, add a common helper to find the ancestor of two
cgroups using each cgroup's ancestor array.

Tested-by: Thadeu Lima de Souza Cascardo &lt;cascardo@igalia.com&gt;
Reviewed-by: Maarten Lankhorst &lt;dev@lankhorst.se&gt;
Reviewed-by: Timur Kristóf &lt;timur.kristof@gmail.com&gt;
Signed-off-by: Natalie Vock &lt;natalie.vock@gmx.de&gt;
Link: https://patch.msgid.link/20260804-dmemcg-aggressive-protect-v8-2-07af96681bf8@gmx.de
</pre>
</div>
</content>
</entry>
<entry>
<title>cgroup: Add cgroup_task_notifier and task migration events</title>
<updated>2026-07-20T07:10:56+00:00</updated>
<author>
<name>Tejun Heo</name>
<email>tj@kernel.org</email>
</author>
<published>2026-07-18T08:12:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=52478777b37ba56bb11d40025df0a03ef65c6acb'/>
<id>52478777b37ba56bb11d40025df0a03ef65c6acb</id>
<content type='text'>
A subsystem can attach to the cgroup hierarchy itself, independent of which
controllers are enabled where - BPF hooks already behave this way and
sched_ext sub-schedulers do too. Controller callbacks can't track task
migrations for them: sched_ext must re-home a task whose migration crosses a
sub-scheduler boundary, but the cpu controller's attach callbacks fire only
when the task_group changes and miss moves whenever the controller topology
is coarser than the sub-scheduler topology.

Add cgroup_task_notifier with per-task migration events mirroring the
can_attach/attach/cancel_attach phases so that a consumer which prepares
per-task state can also veto a migration: CGROUP_TASK_MIGRATING fires
pre-commit, CGROUP_TASK_MIGRATED post-commit and
CGROUP_TASK_MIGRATE_CANCELED unwinds a failed migration. Only migrations
that change a task's dfl cgroup are reported.

Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Reviewed-by: Andrea Righi &lt;arighi@nvidia.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
A subsystem can attach to the cgroup hierarchy itself, independent of which
controllers are enabled where - BPF hooks already behave this way and
sched_ext sub-schedulers do too. Controller callbacks can't track task
migrations for them: sched_ext must re-home a task whose migration crosses a
sub-scheduler boundary, but the cpu controller's attach callbacks fire only
when the task_group changes and miss moves whenever the controller topology
is coarser than the sub-scheduler topology.

Add cgroup_task_notifier with per-task migration events mirroring the
can_attach/attach/cancel_attach phases so that a consumer which prepares
per-task state can also veto a migration: CGROUP_TASK_MIGRATING fires
pre-commit, CGROUP_TASK_MIGRATED post-commit and
CGROUP_TASK_MIGRATE_CANCELED unwinds a failed migration. Only migrations
that change a task's dfl cgroup are reported.

Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Reviewed-by: Andrea Righi &lt;arighi@nvidia.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>cgroup: Use data_race() for task-&gt;flags in task_css_set_check()</title>
<updated>2026-06-25T21:12:19+00:00</updated>
<author>
<name>Guopeng Zhang</name>
<email>zhangguopeng@kylinos.cn</email>
</author>
<published>2026-06-25T01:39:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=da43ea213936494732e52212c59f027967b97173'/>
<id>da43ea213936494732e52212c59f027967b97173</id>
<content type='text'>
task_css_set_check() uses rcu_dereference_check() to verify that
task-&gt;cgroups can be dereferenced. One accepted condition is that the
task is already exiting, tested by checking PF_EXITING in task-&gt;flags.

This check is only part of the CONFIG_PROVE_RCU lockdep predicate. This
was found by KCSAN during fuzz testing. KCSAN can report a data race
when another task flag bit is updated concurrently. One report shows
pids_release() reading task-&gt;flags through task_css_set_check() while
do_task_dead() sets PF_NOFREEZE:

  KCSAN: data-race in task_css() [inline]
  KCSAN: data-race in pids_release()

  task_css()
  pids_release()
  cgroup_release()
  release_task()
  wait_task_zombie()

  value changed: 0x0040004c -&gt; 0x0040804c

The changed bit is PF_NOFREEZE, not PF_EXITING. PF_EXITING remains set
before and after the update, so the task_css_set_check() condition does
not change. This is not a race on task-&gt;cgroups and does not indicate
incorrect pids charging or uncharging.

tools/memory-model/Documentation/access-marking.txt recommends
data_race() for data-racy loads used only for diagnostic purposes. Use
data_race() here to mark the intended diagnostic-only access.

No functional change intended.

Suggested-by: Tejun Heo &lt;tj@kernel.org&gt;
Signed-off-by: Guopeng Zhang &lt;zhangguopeng@kylinos.cn&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_css_set_check() uses rcu_dereference_check() to verify that
task-&gt;cgroups can be dereferenced. One accepted condition is that the
task is already exiting, tested by checking PF_EXITING in task-&gt;flags.

This check is only part of the CONFIG_PROVE_RCU lockdep predicate. This
was found by KCSAN during fuzz testing. KCSAN can report a data race
when another task flag bit is updated concurrently. One report shows
pids_release() reading task-&gt;flags through task_css_set_check() while
do_task_dead() sets PF_NOFREEZE:

  KCSAN: data-race in task_css() [inline]
  KCSAN: data-race in pids_release()

  task_css()
  pids_release()
  cgroup_release()
  release_task()
  wait_task_zombie()

  value changed: 0x0040004c -&gt; 0x0040804c

The changed bit is PF_NOFREEZE, not PF_EXITING. PF_EXITING remains set
before and after the update, so the task_css_set_check() condition does
not change. This is not a race on task-&gt;cgroups and does not indicate
incorrect pids charging or uncharging.

tools/memory-model/Documentation/access-marking.txt recommends
data_race() for data-racy loads used only for diagnostic purposes. Use
data_race() here to mark the intended diagnostic-only access.

No functional change intended.

Suggested-by: Tejun Heo &lt;tj@kernel.org&gt;
Signed-off-by: Guopeng Zhang &lt;zhangguopeng@kylinos.cn&gt;
Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'cgroup-for-7.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup</title>
<updated>2026-06-17T11:03:56+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2026-06-17T11:03:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=83476cc97bc635a3ff502bd194c79bfb1f1ae050'/>
<id>83476cc97bc635a3ff502bd194c79bfb1f1ae050</id>
<content type='text'>
Pull cgroup updates from Tejun Heo:

 - Last cycle deferred css teardown on cgroup removal until the cgroup
   depopulated, so a css is not taken offline while tasks can still
   reference it. Disabling a controller through cgroup.subtree_control
   still had the same problem. This reworks the deferral from per-cgroup
   to per-css so that path is covered too.

 - New RDMA controller monitoring files: rdma.peak for per-device peak
   usage and rdma.events / rdma.events.local for resource-limit
   exhaustion. The max-limit parser was rewritten, fixing two input
   parsing bugs.

 - cpuset: fix a sched-domain leak on the domain-rebuild failure path
   and skip a redundant hardwall ancestor scan on v2.

 - Misc: pair the remaining lockless cgroup.max.* reads with WRITE_ONCE,
   assorted selftest robustness fixes, and doc path corrections.

* tag 'cgroup-for-7.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (22 commits)
  cgroup: Migrate tasks to the root css when a controller is rebound
  docs: cgroup: Fix stale source file paths
  cgroup/cpuset: Free sched domains on rebuild guard failure
  cgroup: pair max limit READ_ONCE() with WRITE_ONCE()
  selftests/cgroup: enable memory controller in hugetlb memcg test
  cgroup/rdma: Drop unnecessary READ_ONCE() on event counters
  cgroup: Defer kill_css_finish() in cgroup_apply_control_disable()
  cgroup: Add per-subsys-css kill_css_finish deferral
  cgroup: Move populated counters to cgroup_subsys_state
  cgroup: Annotate unlocked nr_populated_* accesses with READ_ONCE/WRITE_ONCE
  cgroup: Inline cgroup_has_tasks() in cgroup.h
  cgroup/rdma: document rdma.peak, rdma.events and rdma.events.local
  cgroup/rdma: add rdma.events.local for per-cgroup allocation failure attribution
  cgroup/rdma: add rdma.events to track resource limit exhaustion
  cgroup/rdma: add rdma.peak for per-device peak usage tracking
  selftests/cgroup: check malloc return value in alloc_anon functions
  cgroup/cpuset: Skip hardwall ancestor scan in cpuset v2 in cpuset_current_node_allowed()
  selftests/cgroup: fix misleading debug message in test_cgfreezer_time_child
  selftests/cgroup: fix child process escaping to parent cleanup in test_cpucg_nice
  selftests/cgroup: Add NULL check after malloc in cgroup_util.c
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull cgroup updates from Tejun Heo:

 - Last cycle deferred css teardown on cgroup removal until the cgroup
   depopulated, so a css is not taken offline while tasks can still
   reference it. Disabling a controller through cgroup.subtree_control
   still had the same problem. This reworks the deferral from per-cgroup
   to per-css so that path is covered too.

 - New RDMA controller monitoring files: rdma.peak for per-device peak
   usage and rdma.events / rdma.events.local for resource-limit
   exhaustion. The max-limit parser was rewritten, fixing two input
   parsing bugs.

 - cpuset: fix a sched-domain leak on the domain-rebuild failure path
   and skip a redundant hardwall ancestor scan on v2.

 - Misc: pair the remaining lockless cgroup.max.* reads with WRITE_ONCE,
   assorted selftest robustness fixes, and doc path corrections.

* tag 'cgroup-for-7.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (22 commits)
  cgroup: Migrate tasks to the root css when a controller is rebound
  docs: cgroup: Fix stale source file paths
  cgroup/cpuset: Free sched domains on rebuild guard failure
  cgroup: pair max limit READ_ONCE() with WRITE_ONCE()
  selftests/cgroup: enable memory controller in hugetlb memcg test
  cgroup/rdma: Drop unnecessary READ_ONCE() on event counters
  cgroup: Defer kill_css_finish() in cgroup_apply_control_disable()
  cgroup: Add per-subsys-css kill_css_finish deferral
  cgroup: Move populated counters to cgroup_subsys_state
  cgroup: Annotate unlocked nr_populated_* accesses with READ_ONCE/WRITE_ONCE
  cgroup: Inline cgroup_has_tasks() in cgroup.h
  cgroup/rdma: document rdma.peak, rdma.events and rdma.events.local
  cgroup/rdma: add rdma.events.local for per-cgroup allocation failure attribution
  cgroup/rdma: add rdma.events to track resource limit exhaustion
  cgroup/rdma: add rdma.peak for per-device peak usage tracking
  selftests/cgroup: check malloc return value in alloc_anon functions
  cgroup/cpuset: Skip hardwall ancestor scan in cpuset v2 in cpuset_current_node_allowed()
  selftests/cgroup: fix misleading debug message in test_cgfreezer_time_child
  selftests/cgroup: fix child process escaping to parent cleanup in test_cpucg_nice
  selftests/cgroup: Add NULL check after malloc in cgroup_util.c
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'cgroup-for-7.1-rc4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup</title>
<updated>2026-05-22T23:28:47+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2026-05-22T23:28:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=de37e502a315677138009d2965f87e2c0721e76f'/>
<id>de37e502a315677138009d2965f87e2c0721e76f</id>
<content type='text'>
Pull cgroup fixes from Tejun Heo:
 "Two rstat fixes:

   - Out-of-bounds access in the css_rstat_updated() BPF kfunc when
     called with an unchecked user-supplied cpu

   - Over-strict NMI guard after the recent switch to try_cmpxchg left
     sparc and ppc64 unable to queue rstat updates from NMI"

* tag 'cgroup-for-7.1-rc4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup: rstat: relax NMI guard after switch to try_cmpxchg
  cgroup/rstat: validate cpu before css_rstat_cpu() access
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull cgroup fixes from Tejun Heo:
 "Two rstat fixes:

   - Out-of-bounds access in the css_rstat_updated() BPF kfunc when
     called with an unchecked user-supplied cpu

   - Over-strict NMI guard after the recent switch to try_cmpxchg left
     sparc and ppc64 unable to queue rstat updates from NMI"

* tag 'cgroup-for-7.1-rc4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup: rstat: relax NMI guard after switch to try_cmpxchg
  cgroup/rstat: validate cpu before css_rstat_cpu() access
</pre>
</div>
</content>
</entry>
<entry>
<title>cgroup/rstat: validate cpu before css_rstat_cpu() access</title>
<updated>2026-05-18T19:31:52+00:00</updated>
<author>
<name>Qing Ming</name>
<email>a0yami@mailbox.org</email>
</author>
<published>2026-05-16T07:08:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=8817005efbdfdf5d4e4814cb5dc52b53d12917d7'/>
<id>8817005efbdfdf5d4e4814cb5dc52b53d12917d7</id>
<content type='text'>
css_rstat_updated() is exposed as a BPF kfunc and accepts a
caller-provided cpu argument. The function uses cpu for per-cpu rstat
lookups without checking whether it refers to a valid possible CPU.

A BPF iter/cgroup program with CAP_BPF and CAP_PERFMON can pass an
invalid cpu value. On an unfixed UBSCAN_BOUNDS test kernel, cpu ==
0x7fffffff triggers:

  UBSAN: array-index-out-of-bounds in kernel/cgroup/rstat.c:31:9
  index 2147483647 is out of range for type 'long unsigned int [64]'
  Call Trace:
    css_rstat_updated
    bpf_iter_run_prog
    cgroup_iter_seq_show
    bpf_seq_read

Add cpu validation to the BPF-facing css_rstat_updated() kfunc and
move the common implementation to __css_rstat_updated() for in-kernel
callers.

Fixes: a319185be9f5 ("cgroup: bpf: enable bpf programs to integrate with rstat")
Signed-off-by: Qing Ming &lt;a0yami@mailbox.org&gt;
Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
css_rstat_updated() is exposed as a BPF kfunc and accepts a
caller-provided cpu argument. The function uses cpu for per-cpu rstat
lookups without checking whether it refers to a valid possible CPU.

A BPF iter/cgroup program with CAP_BPF and CAP_PERFMON can pass an
invalid cpu value. On an unfixed UBSCAN_BOUNDS test kernel, cpu ==
0x7fffffff triggers:

  UBSAN: array-index-out-of-bounds in kernel/cgroup/rstat.c:31:9
  index 2147483647 is out of range for type 'long unsigned int [64]'
  Call Trace:
    css_rstat_updated
    bpf_iter_run_prog
    cgroup_iter_seq_show
    bpf_seq_read

Add cpu validation to the BPF-facing css_rstat_updated() kfunc and
move the common implementation to __css_rstat_updated() for in-kernel
callers.

Fixes: a319185be9f5 ("cgroup: bpf: enable bpf programs to integrate with rstat")
Signed-off-by: Qing Ming &lt;a0yami@mailbox.org&gt;
Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>cgroup: Move populated counters to cgroup_subsys_state</title>
<updated>2026-05-15T17:24:26+00:00</updated>
<author>
<name>Tejun Heo</name>
<email>tj@kernel.org</email>
</author>
<published>2026-05-05T00:51:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c4799253a3ee74ebb27be72fb991c597a5902c01'/>
<id>c4799253a3ee74ebb27be72fb991c597a5902c01</id>
<content type='text'>
Later patches replace the cgroup-level finish_destroy_work deferral added
by 93618edf7538 ("cgroup: Defer css percpu_ref kill on rmdir until cgroup
is depopulated") with a per-subsys-css deferral. That needs each subsystem
css to track its own populated count. Move the populated counters from
cgroup onto cgroup_subsys_state. cgroup-&gt;self is itself a
cgroup_subsys_state and self.parent walks the same chain as cgroup_parent(),
so cgroup_update_populated() generalizes to a single css_update_populated()
taking a css. The cgroup-side bookkeeping runs only when the walk started
from a self css.

Keep nr_populated_{domain,threaded}_children on cgroup. Both sum to
self.nr_populated_children, but staying as dedicated fields to allow readers
like cgroup_can_be_thread_root() unlocked access.

css_set_update_populated() also walks the per-subsys-css chain so each
subsystem css's hierarchical populated count is maintained. No reader
consumes those counts yet.

Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Later patches replace the cgroup-level finish_destroy_work deferral added
by 93618edf7538 ("cgroup: Defer css percpu_ref kill on rmdir until cgroup
is depopulated") with a per-subsys-css deferral. That needs each subsystem
css to track its own populated count. Move the populated counters from
cgroup onto cgroup_subsys_state. cgroup-&gt;self is itself a
cgroup_subsys_state and self.parent walks the same chain as cgroup_parent(),
so cgroup_update_populated() generalizes to a single css_update_populated()
taking a css. The cgroup-side bookkeeping runs only when the walk started
from a self css.

Keep nr_populated_{domain,threaded}_children on cgroup. Both sum to
self.nr_populated_children, but staying as dedicated fields to allow readers
like cgroup_can_be_thread_root() unlocked access.

css_set_update_populated() also walks the per-subsys-css chain so each
subsystem css's hierarchical populated count is maintained. No reader
consumes those counts yet.

Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>cgroup: Annotate unlocked nr_populated_* accesses with READ_ONCE/WRITE_ONCE</title>
<updated>2026-05-15T17:24:22+00:00</updated>
<author>
<name>Tejun Heo</name>
<email>tj@kernel.org</email>
</author>
<published>2026-05-05T00:51:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=44fabf05634ce9e90b3fb179ea962995b7bbaa09'/>
<id>44fabf05634ce9e90b3fb179ea962995b7bbaa09</id>
<content type='text'>
cgroup_update_populated() updates nr_populated_csets,
nr_populated_domain_children, and nr_populated_threaded_children under
css_set_lock, but cgroup_has_tasks(), cgroup_is_populated(), and
cgroup_can_be_thread_root() read them without holding it. Use
READ_ONCE/WRITE_ONCE.

Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
cgroup_update_populated() updates nr_populated_csets,
nr_populated_domain_children, and nr_populated_threaded_children under
css_set_lock, but cgroup_has_tasks(), cgroup_is_populated(), and
cgroup_can_be_thread_root() read them without holding it. Use
READ_ONCE/WRITE_ONCE.

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