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git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fixes from Tejun Heo:
- cgroup.kill did not kill a process whose thread group leader had
exited while other threads still ran, nor those threads once moved to
another cgroup, letting a process survive its container being killed
- A cgroup.procs write under favordynmods could migrate a newly forked
process before fork linked it to its cgroup, corrupting cgroup task
lists
- cpuset partition fixes for nested hierarchies: invalidation, revival,
shrinking and switches between root and isolated could leak isolated
CPUs, skip or miscompute the housekeeping check, or leave wrong
effective CPUs:
- A root partition can no longer be created under an isolated
parent or stay valid under one, as disabling it could leave no
housekeeping CPUs
- Enabling a partition failed when a grandchild held tasks,
although the parent had none of its own
- Separately, an allocation racing with a cpuset.mems update could
drop its mempolicy nodemask and land on the wrong node, and a
memoryless node in cpuset.mems triggered a spurious "movable
nodes only" warning
- Two no-functional-change cleanups of the effective CPU
computation
* tag 'cgroup-for-7.4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (27 commits)
cgroup/cpuset: Integrate compute_partition_effective_cpumask() into compute_effective_cpumask()
cgroup/cpuset: Relocate compute_*effective_cpumask() and compute_effective_nodemask()
cgroup/cpuset: Release invalid isolated CPUs with a shrunk root partition parent
cgroup/cpuset: Release invalid isolated CPUs in compute_partition_effective_cpumask()
cgroup/cpuset: Make sure compute_partition_effective_cpumask() is only called for valid partition
cgroup/cpuset: Prevent recursive call of remote_cpus_update() via update_cpumasks_hier()
selftests/cgroup: Check for a single range nohz_full CPUs before running test matrix
cgroup/cpuset: Minor fixes to prstate_housekeeping_conflict()
cgroup/cpuset: Fix incorrect effective_cpus bug in update_cpumasks_hier()
cgroup/cpuset: Properly compute effective xcpus in update_parent_effective_cpumask()
cgroup/cpuset: Find furthest isolated ancestor for invalidated isolated partition
cgroup: don't kill migrated processes through their exiting threads
cgroup/cpuset: check effective mems for a movable-only configuration
cgroup/cpuset: Fix task checking when enabling a partition
cgroup: serialize migrations of newly forked processes
selftests/cgroup: test cgroup.kill with an exited thread group leader
cgroup: fix cgroup.kill for exited thread group leader
selftests/cgroup: Skip test_cpuset_prs.sh test if some required CPUs are offline
selftests/cgroup: Add tests for nohz_full housekeeping check
selftests/cgroup: Add tests for isolcpus housekeeping check
...
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compute_effective_cpumask()
Update compute_effective_cpumask() to call
compute_partition_effective_cpumask() directly if the given cpuset is
a valid remote or local partition root. This simplifies the call sites
where they are being involved. No functional change is expected.
Suggested-by: Ridong Chen <ridong.chen@linux.dev>
Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Guopeng Zhang <zhangguopeng@kylinos.cn>
Signed-off-by: Tejun Heo <tj@kernel.org>
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compute_effective_nodemask()
Relocate compute_partition_effective_cpumask(),
compute_effective_cpumask(), and compute_effective_nodemask() together so
that compute_effective_cpumask() and compute_partition_effective_cpumask()
can be further integrated together. There is no functional change.
Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Guopeng Zhang <zhangguopeng@kylinos.cn>
Signed-off-by: Tejun Heo <tj@kernel.org>
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It is also reported by sashiko that there may be leakages of isolated
CPUs when a root partition parent shrinks its effective_xcpus with
isolated partition children. Leakage here means that isolated_cpus may
contain extra CPUs that are not in any isolated partitions and not boot
time isolated. Those CPUs cannot be used in any isolated partitions
anymore.
There are 2 different cases here. The effective_xcpus becomes empty and
the isolated partition should be invalidated in this case. Alternatively
some of its effective_xcpus are not in parent's effective xcpus but
still have some valid effective_xcpus left. The isolated partition can
remain valid. In both cases, the invalid isolated CPUs will have to be
released from isolated_cpus if appropriate.
Fix that by calling isolated_cpus_release() to release those isolated
CPUs from isolated_cpus.
New test cases are added to test_cpuset_prs.sh to test this.
Fixes: 11e5f407b64a ("cgroup/cpuset: Keep track of CPUs in isolated partitions")
Signed-off-by: Waiman Long <longman@redhat.com>
Reviewed-by: Guopeng Zhang <zhangguopeng@kylinos.cn>
Tested-by: Guopeng Zhang <zhangguopeng@kylinos.cn>
Signed-off-by: Tejun Heo <tj@kernel.org>
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compute_partition_effective_cpumask()
It is found by sashiko that when a child isolated partition with parent
root partition is invalidated in compute_partition_effective_cpumask(),
the switching of the isolated exclusive CPUs from child to parent will
not be reflected in isolated_cpus leading to CPU leakage. Fix that by
calling isolated_cpus_update() when that happens.
Also simplify compute_partition_effective_cpumask() by doing
child partition invalidation only for the special case of no more
effective_cpus left in a populated parent. The other case doesn't
actually warrant invalidation at this stage and subsequent iteration
in update_cpumasks_hier() and update_parent_effective_cpumask() for
that child should handle that.
Also drop the make_partition_invalid() helper by inlining it into
compute_partition_effective_cpumask() as it is the only caller.
A new test case is add to test_cpuset_prs.sh to verify this.
Fixes: 11e5f407b64a ("cgroup/cpuset: Keep track of CPUs in isolated partitions")
Signed-off-by: Waiman Long <longman@redhat.com>
Reviewed-by: Guopeng Zhang <zhangguopeng@kylinos.cn>
Tested-by: Guopeng Zhang <zhangguopeng@kylinos.cn>
Signed-off-by: Tejun Heo <tj@kernel.org>
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called for valid partition
With visual inspection to make sure that
compute_partition_effective_cpumask() is only called for valid partition
root, it was found that the function can be called for an invalidated
partition near the end of cpuset_hotplug_update_tasks(). When partcmd is
set, update_parent_effective_cpumask() is called to either invalidate a
valid partition or with partcmd_update to check if an invalid partition
can be switched back to valid. In both cases, cpuset_force_rebuild()
should be invoked. However, compute_partition_effective_cpumask()
should only be called when an invalid partition is switched back to
valid. When a partition is invalidated, compute_effective_cpumask()
should be called instead.
Also add a WARN_ON_ONCE() in compute_partition_effective_cpumask() to
ensure that a valid partition root is passed in.
Fixes: 72c6303acfa1 ("cgroup/cpuset: Take isolated CPUs out of workqueue unbound cpumask")
Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Guopeng Zhang <zhangguopeng@kylinos.cn>
Signed-off-by: Tejun Heo <tj@kernel.org>
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update_cpumasks_hier()
Guopeng reports that changing the cpumask of a remote partition root
may set the effective_cpus of the top_cpuset incorrectly. It is
due to the following call sequence:
update_cpumask()
-> partition_cpus_change()
-> remote_cpus_update()
-> update_sibling_cpumasks()
-> update_cpumasks_hier()
-> remote_cpus_update()
The second remote_cpus_update() call passes in the cs->effective_xcpus
instead of the trialcs->effective_xcpus of the first remote_cpus_update()
call. As a result, the second call can revert what has been done in
the first call leading to incorrect effective_cpus of the top_cpuset
as well as subpartitions_cpus.
Fix that by adding a new remote_partition_updating flag into the cpuset
structure to indicate that a remote partition is being updated and
update_cpumasks_hier() should skip the whole subtree as update_cpumask()
or update_exclusive_cpumask() which calls partition_cpus_change()
will eventually calls update_cpumasks_hier() for that subtree anyway.
This new flag is currently set only in remote_cpus_update() to prevent
recursive call of remote_cpus_update() on the same cpuset.
A test case is added to test_cpuset_prs.sh to verify this change.
Reported-by: Guopeng Zhang <zhangguopeng@kylinos.cn>
Link: https://lore.kernel.org/lkml/20261010075947.333549-2-guopeng.zhang@linux.dev
Reviewed-by: Guopeng Zhang <zhangguopeng@kylinos.cn>
Tested-by: Guopeng Zhang <zhangguopeng@kylinos.cn>
Fixes: f62a5d39368e ("cgroup/cpuset: Remove remote_partition_check() & make update_cpumasks_hier() handle remote partition")
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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Commit 9527ff78a413 ("cgroup/cpuset: Consider all the exclusive CPUs when
doing housekeeping check") changes the way prstate_housekeeping_conflict()
is being used by considering all the exclusive xcpus to be owned by the
partition when doing housekeeping check. However there are two minor
issues reported by sashiko with that patch:
1) In partition_cpus_change(), prstate_housekeeping_conflict() can
be called with an invalid partition root. In that case, there are
no isolated CPUs that are going to be returned back to the system to
become housekeeping CPUs, so the calculation of the del_cpus cpumask
is meaningless.
2) The checking of del_cpus in prstate_housekeeping_conflict() to see
if it can contain an active housekeeping CPU that can be returned to the
system ignores the fact that an active CPU not in HK_TYPE_DOMAIN_BOOT HK
cpumask will not become an active housekeeping CPU when it is released
by an isolated partition.
Update the existing code to handle these two issues properly to make
prstate_housekeeping_conflict() produce more accurate result.
Fixes: 9527ff78a413 ("cgroup/cpuset: Consider all the exclusive CPUs when doing housekeeping check")
Signed-off-by: Waiman Long <longman@redhat.com>
Reviewed-by: Guopeng Zhang <zhangguopeng@kylinos.cn>
Signed-off-by: Tejun Heo <tj@kernel.org>
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With the introduction of cpuset.cpus.exclusive, the computation of
effective_cpus differs depending on if a cpuset is a valid partition
root or not.
In update_cpumasks_hier(), effective_cpus is computed early
to check if the current subtree can be skipped. Later on
update_parent_effective_cpumask() may be called which can change the
partition state from valid to invalid or vice versa. If the partition
state changes, the previously computed effective_cpus may no longer be
valid. Fix that by recomputing effective_cpus again when that happens.
Also add a new test case into test_cpuset_prs.sh to verify this change.
Fixes: e2ffe502ba45 ("cgroup/cpuset: Add cpuset.cpus.exclusive for v2")
Signed-off-by: Waiman Long <longman@redhat.com>
Reviewed-by: Guopeng Zhang <zhangguopeng@kylinos.cn>
Signed-off-by: Tejun Heo <tj@kernel.org>
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update_parent_effective_cpumask()
Since the introduction of cpuset.cpus.exclusive in commit
e2ffe502ba45 ("cgroup/cpuset: Add cpuset.cpus.exclusive for v2"), a
compute_effective_exclusive_cpumask() helper which is later renamed to
compute_excpus() is added to compute the effective xcpus of a partition
root. However update_parent_effective_cpumask() is not updated in all
proper places to use the new helper to check if a given cpuset should
remain a valid partition root. This can cause a cpuset to incorrectly
remain a valid partition root even if no effective xcpus is left.
Fix that problem by using compute_excpus() to compute the effective xcpus
into delmask in all cases except partcmd_disable, partcmd_invalidate
or partcmd_update with newmask set and use it for tasks_nocpu_error()
check as well as checking its emptiness. This enables us to catch invalid
partition root more accurately in update_parent_effective_cpumask().
In the case of partcmd_update with newmask set, the passed in new
effective xcpus value will directly be used in the tasks_nocpu_error()
check without relying on old data in the cpuset.
For the partcmd_update with NULL newmask case, the cpu exclusivity test
there is also relaxed to be performed only if exclusive_cpus is empty.
Some test case are added to test_cpuset_prs.sh for invalidating a
partition root due to its effective xcpus becoming empty as well as
making sure that an invalid partition can only be revived when exclusive
CPUs are available agin.
Fixes: e2ffe502ba45 ("cgroup/cpuset: Add cpuset.cpus.exclusive for v2")
Signed-off-by: Waiman Long <longman@redhat.com>
Reviewed-by: Guopeng Zhang <zhangguopeng@kylinos.cn>
Tested-by: Guopeng Zhang <zhangguopeng@kylinos.cn>
Signed-off-by: Tejun Heo <tj@kernel.org>
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partition
Commit 46b885416c27 ("cgroup/cpuset: Fix a missing isolated_cpus
update in update_cpumasks_hier()") searches for the closet partition
root ancestor to determine if the isolated CPUs in a to be invalidated
isolation partition should be removed from isolated_cpus or not.
As reported by sashiko, this method may not work when there is a deeply
nested isolated partition hierarchy. For instance, Consider a nested
hierarchy A0 -> A1 -> A2 -> A3 where all four are PRS_ISOLATED:
A0: effective_xcpus = 0-4
A1: effective_xcpus = 1-4
A2: effective_xcpus = 2-4
A3: effective_xcpus = 3-4
When A1 shrinks its exclusive_cpus from 1-4 to 1-2, A2 will update it
effective_xcpus to 2. A3 will find its closet partition root ancestor
A2 and decides that its effective_xcpus 3-4 should be removed from
isolated_cpus which is incorrect.
Address this corner case by adding a new isolated_cpus_release() helper
to replace the existing ancestor_partition() helper. This new helper
will search for the furthest isolated partition root ancestor to decide
if some or all of its isolated CPUs should be removed from isolated_cpus
and also perform the removal when appropriate.
The is_remote_partition() and is_local_partition() helpers are also
moved up so they can be used in earlier functions.
There are other pre-existing problems that will still prevent the
above test case to work correctly. These problems will be addressed in
subsequent patches.
Fixes: 46b885416c27 ("cgroup/cpuset: Fix a missing isolated_cpus update in update_cpumasks_hier()")
Signed-off-by: Waiman Long <longman@redhat.com>
Reviewed-by: Guopeng Zhang <zhangguopeng@kylinos.cn>
Signed-off-by: Tejun Heo <tj@kernel.org>
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Pull drm updates from Dave Airlie:
"Highlights:
- core: a lot of atomic refactoring in progress, panic got split into
a core/helpers model
- amdgpu: enables HDMI 2.1 FRL and other good things finally, UAlink
over Ethernet support
- xe: has a bunch of CRI support, ras error for bad vram, memory
offlining support.
- msm: enables a bunch more GPUs.
Otherwise it's a the usual mountain of stuff all over the place.
Details:
rust:
- I/O tree shared with driver-core
- DMA tree shared with driver-core
- allow aux registration data closures to return covariant sub-fields
- Implement Send and Sync for MapleTree
- add pci resource flags and IORESOURCE_MEM_64
drm/rust:
- add dma_fence abstraction
- init DRM registrations and their data in place
- drop unused flags argument to registration
vgaarb:
- rework API to pass a private ptr instead of pci device
sound:
- adapt to omapdrm changes
gem:
- add callback for handle count going to 0
gpusvm:
- share one HMM fault and keep single mappings inline
pagemap:
- Prevent CPU stalls during unbounded pagemap teardown
dma-fence:
- fix docs
vga_switcheroo:
- disconnect from fbcon
- update fbcon from within fbdev emulation
atomic:
- move DRM from state reset callbacks to atomic_create_state
- remove drm_simple_encoder_init
panic:
- split into core and helpers
buddy:
- improve dirty tracking
clients:
- improve vmap handling
- fbdev: Move helpers from drm_kms_helper.ko to drm_client_lib.ko
display:
- export HDMI SCDC status data via debugfs
- rework SCDC for better HDMI 2.0 support
- dp/mst: improve DPCD compliance
edid:
- parse AMD VSDB
- parse ALLM/VRR capabilities
- support detecting panel size
log:
- add drm_warn_ratelimited
sched:
- cleanup interface
- add missing locking
- fix run-queue cleanup
- fix locking
sysfb:
- remove obsolete quirk for Lenovo D330
- fix panel orientation for non-native display modes
- drop drm_class_device_register
colorop:
- provide DRM_COLOR_OP_FIXED_MATRIX
bridge:
- analogix: Support eDP lane mapping
- ti-sn65dsi83: Support LVDS Channel B on SN65DSI84
- Select DRM_PANEL_BRIDGE for various drivers that require it
- add chrontel ch7218a support
panel:
- panel-edp: Support MNE007QS3-F, TM140VDXP15, and KD116N36-30NB-A001
- samsung-s6d16d0: Use mipi_dsi_*_multi() functions
- support Ilitek ILI7836A OLED plus DT bindings
- support Novatek NT36532 plus DT bindings
- convert several drivers to managed cleanup
- fix Kconfig selections
- edp:
- Add support for BOE NV140FHM-T0A
- Support CSOT MNE007QB1-1
- NV140WU2-M70
- ebbg-ft8719: Fix MODULE_LICENSE() string; Improve initialization
- samsung: Share test-key helpers
- ilitek-ili9882t: Support Ilitek IL79600A plus DT bindings
- simple: Support Truly TFT320240-229-E plus DT bindings; Support BOE
DV215FHM-R01 plus DT bindings
- Refactor struct drm_panel to contain struct drm_bridge plus fallout
in various panel drivers
- Add support for BOE Novatek NT51021, Retroid Pocket 6, Raydium
RM69220 DDIC panels, Sharp LQ138P1JX61 eDP, BOE NV140FHD-N43, AUO
B140HAN04.0, AUO 0x0db3, panels.
amdgpu:
- use AMD VSDB for freesync
- implement YUV-to-RGB with fixed-matrix colorop
- enable FRL for HDMI
- HDMI 2.1 freesync support
- HDMI 2.1 ALLM support
- HDMI 2.1 VRR support
- UALoE (UALink over Ethernet) support
- add syncobj_points to userq signal ioctl
- drop unused kunit tests
- NBIO/GC/MMHUB/SMU updates/fixes
- GPU spatial partitioning updates
- display kunit fixes
- userq fixes
- RGB quantization fixes
- DC RMCM refactor
- DP MST fixes
- USB4 fixes
- add new trace events
- Rework display instance handling
- stack frame size fixes for various compilers/configs
- VCN 4/5 reset fixes
- freesync updates
- cursor refactor
- Fix direct scanout alpha on some DRM_FORMATs
- Expand Mac reserved memory workaround
- Make runtime pm more fine grained
amdkfd:
- updates and fixes
- GC 10 CU occupancy support
radeon:
- eDP fix for DCE3.2 iMacs
xe:
- add drm_ras netlink error event support
- add memory page offlining support
- introduce error threshold to drm_ras
- fix stale GTT mappings on unmap
- reject page faults for non-page fault mode scratch VM
- enable CRI package and VRAM temperatures
- introduce cold reset recovery
- handle CRI+ power interval encoding
- VF migration for multi-queue
- handle exec queue teardown after hot unplug
- alerts and controller enabling modifications
- use IBCv3 on PTL
- VRAM health check
- report GT TDR and VM rebind faults using SIGID
- add multi_queue_active_lrca debugfs
- shrinker: Runtime PM reference for non-system memory
- guc: Add simple KLV decoder helpers
- debugfs: Expose per-engine idle status
- Keep walking on SVM eviction failure
- Nuke PTs only after unlinking contested VMAs
- limit sg segment size to PAGE_SIZE on Xen PV
- keep VF LMEM bar size low if no VFs
- CPU binds and ULLS on migration queue
- New PTL PCI ID
- Enable PXP for NVL-S
- Do not dma_fence_put zero fences in err_out path
- Refresh TTM LRU on SVM prefetch
- export device UID in sysfs
i915:
- rename GEN6_PCODE_DATA to match spec
- fix incorrect RCU teardown order
- fix potential UAF in command parsing
- avoid WARN splat during RPS boosting race
- use simpler min functions
- Fixes to make i915 work well with PREEMPT_RT
i915/display:
- Enable CMRR (Content Match Refresh Rate) in fixed-RR VRR path
- Switch DG2 MPLL to DPLL framework
- DP-HDMI PCON DSC fixes
- limit invalid joiner combinations
- CDCLK related fixes and refactor around PCODE integration
- Gate UHBR SST SDP splitting on sink caps
- add HDMI TMDS audio bandwidth check
- vswing/preemph override
- enable AS SDP Skip frames
- Handle negative configuration index on DP link caps for robustness
- Preparation for enabling SDR plane color pipeline
- An eDP quirk for HP Pavilion Plus
- Introduce PME (Power Management Event) support on display hotplug
- Handle VSC SDP revision 7 in unpack
msm:
- CI:
- Dropped sc7180 trogdor lazor from the CI
- Core:
- Fixed msm_ioremap for resources without a name
- Changed msm.separate_gpu_kms to default to auto selection
- GPU:
- Enable CLX (Current Limit eXtension) for gen8 to avoid exceeding
limits on CX/GX rails
- New GPUs: a830 (Pakala), a845 (Maili), a850 (Hawi), x2-85
(Mahua)
- Fix VBIF halt mask on a306, which was preventing runpm suspend
- Enable THP support for GEM buffers
- Add modparam to disable waiting on fences in shrinker
- Drop use of drm_prime_sg_to_page_array()
- a5xx: don't read the GPMU registers on GPUs without a GPMU
- a2xx/a3xx/a5xx: hangcheck progress detection
- a6xx: gmuwrapper runpm fix
- Calculate reported GMEM size based on active slices
- Split a6xx/a7xx/a8xx catalog
- DP:
- Picked up some preparation patches for the MST support
- Fixed reported status of the link training
- DPU:
- Fixed CRTC bandwidth computation
- Fixed DSC programming
- Fixed encoder disablement path
- DSI:
- Fixed VM leak in error path
- Indention fix
- MDP5:
- Added MSM8952 configuration
- Dropped incorrect cursor pipe on MSM8976/56
- HDMI:
- Small fixes
nouveau:
- improve runtime PM on R570 GSP firmware
- various fixes throughout the driver
- dispnv50: support 2.147 GHz pixel clock in GB20x
nova:
- add initial uapi concept
- add initial PRAMIN access support
- add GpuMm centralized memory manager
- add GPU VM and BAR1 support
- add GPU interrupts and GSP events support
- GSP messaging fixes
tyr:
- use bitfield!
- zero unsupported and newly added GPU info fields
- limit doorbell array to 17 entries
exynos:
- FIMD fixes
- Fix clock leak on resume error path
- Fix Sparse warnings by adding missing __iomem annotation
- VIDI cleanup
- Replace kmalloc() and copy_from_user() with memdup_user()
amdxdna:
- fix BO handling
- Support AIE2 rev 9
- Fix UAF access in scheduler fences
- Update workqueue interface
- expose busy time via fdinfo
ast:
- support 256-byte EDID
hyperv_drm:
- remove support for pre win10 hosts
komeda:
- fix GLB_CORE_ID usage
omap:
- report HDMI hotplug events to ASoC HDMI codec
panthor:
- provide gpu_cache_flush tracepoint
- improve dma_fence signalling latency
- improve locking
- export scheduling information via debugfs
- Validate user-space input against firmware limits
qaic:
- reject BOs that exceed maximum page count
- add missing include statements
verisilicon:
- fix hardware cursor offsets
vkms:
- implement YUV-to-RGB with fixed-matrix colorop
gma500:
- avoid unsupported ARGB formats in primary plane
hibmc:
- handle vblank interrupts correctly
ivpu:
- add DRM_IVPU_CAP_CMDQ_SET_PRIORITY
- support command-queue priority ioctl
- Simplify NULL-pointer handling in cleanup code
arcpgu:
- replace simple-display pipeline with regular atomic helpers
aspeed:
- replace simple-display pipeline with regular atomic helpers
gm12u320:
- replace simple-display pipeline with regular atomic helpers
imagination:
- various improvement to firmware interaction
- add job to pvr_job_submit_fw trace event
mali-dp:
- fix runtime PM leak
mcde:
- replace simple-display pipeline with regular atomic helpers
p111:
- replace simple-display pipeline with regular atomic helpers
- drop unsupported alpha formats from primary plane
rcar-du:
- support Renesas R-Car V4H DSC
- dsi: Support larger transfers with AXI memory
- Support RZ/G3L SoC
repaper:
- replace simple-display pipeline with regular atomic helpers
rockchip:
- dsi: improve PHY timings
ssd130x:
- support Solomon SSD1351 OLED plus DT bindings
- ssd133x: upgrade color format to RGB565
- ssd132x: Set correct hardware window when clearing screen
tve200:
- replace simple-display pipeline with regular atomic helpers
xen:
- replace simple-display pipeline with regular atomic helpers
v3d:
- improve job handling under perfmon
vc4:
- reliably reset V3D
- drop brcm,vc4-v3d compatible
virtio:
- fix damage handling
- Support ARGB8888 for virtio primary planes.
host1x:
- Support partitioning
imx:
- Replace simple-display with regular atomic helpers
mxsfb:
- Support bus formats plus DT bindings
tegra:
- improve syncobj handling on submit
panfrost:
- add Mali-G68 support
- improve GPU reset handling
rockchip:
- add HDMI 2.0 support to dw-hdmi-qp
- improve HPD handling"
* tag 'drm-next-2026-10-21' of https://gitlab.freedesktop.org/drm/kernel: (2324 commits)
drm/adp: Switch to drm_atomic_helper_connector_create_state
drm/malidp: Convert to atomic_create_state
drm/vc4: Switch to drm_atomic_helper_connector_create_state
drm/sysfb: Switch to drm_atomic_helper_connector_create_state
drm/solomon: ssd130x: Switch to drm_atomic_helper_connector_create_state
drm/imx: ipuv3: Switch to drm_atomic_helper_connector_create_state
drm/hyperv: Switch to drm_atomic_helper_connector_create_state
drm/bridge: megachips: Switch to drm_atomic_helper_connector_create_state
drm/bridge: lontium-lt8912b: Switch to drm_atomic_helper_connector_create_state
drm/arm: komeda: Switch to drm_atomic_helper_connector_create_state
drm/appletbdrm: Fix incorrect error message on encoder attach failure
drm/sun4i: hdmi: Convert to drmm_connector_hdmi_init()
drm/rockchip: rk3066_hdmi: Advertise HDMI 1.4 capabilities
drm/bridge: lontium-lt9611: Advertise HDMI 1.4 capabilities
drm/bridge: ite-it66121: Advertise HDMI 1.2 capabilities
drm/bridge: ite-it6263: Advertise HDMI 1.3 capabilities
drm/bridge: ite-it6263: Drop redundant .mode_valid hook
drm/bridge: inno-hdmi: Advertise HDMI 1.2 capabilities
drm/bridge: adv7511: Advertise HDMI 1.2 capabilities
drm/sched: Document entity->stopped is protected by entity->lock
...
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|
Since commit da13e0e72a73 ("cgroup: fix cgroup.kill for exited thread
group leader"), __cgroup_kill() visits every thread in the cgroup and
sends SIGKILL with PIDTYPE_TGID, so each visited thread takes down its
whole thread group.
A thread that has started exiting can stay in a cgroup after its process
has been moved out of it. cgroup_migrate_add_task() skips PF_EXITING
tasks, and the thread is only unlinked by cgroup_task_dead() after its
final context switch. mm_release() clears the thread's clear_child_tid
word and wakes the joiner well before that, so pthread_join() can return
while the thread is still in the old cgroup.
If cgroup.kill is written in that window, __cgroup_kill() finds the
exiting thread and complete_signal() passes the group-wide SIGKILL on to
a live thread, killing a process that already left the cgroup. The cgroup
selftest test_stress.sh runs into this: test_cgcore_proc_migration()
joins its threads, moves itself back to the root cgroup, and cg_destroy()
falls back to cgroup.kill on the old cgroup when rmdir() fails with
EBUSY, so test_core kills itself. KernelCI has been reporting
"with_stress.sh: line 94: ... Killed" on several arm64 boards since the
commit reached linux-next.
Keep visiting every thread, but go back to sending SIGKILL to the thread
that was found. A SIGKILL sent to a live thread still kills its whole
thread group, so both cases fixed by that commit stay fixed, and
task_can_queue_signal() drops one sent to a thread that is already
exiting.
Fixes: da13e0e72a73 ("cgroup: fix cgroup.kill for exited thread group leader")
Cc: stable@vger.kernel.org # v5.14+
Link: https://lore.kernel.org/all/179272264722.329188.4773475583351189022@6e52bff8000c/
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
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|
git://git.kernel.org/pub/scm/linux/kernel/git/modules/linux
Pull module updates from Petr Pavlu:
- Ignore local labels and mapping symbols during module load
These symbols were already ignored during kallsyms address-to-symbol
lookups. Filter them out earlier during module loading to reduce
lookup overhead and prevent them from appearing in /proc/kallsyms.
- Fix potentially incorrect access of SetOnce<T> when setting Rust
module parameters.
- Fix a potential read of an uninitialized count when printing taint
information for unloaded modules.
- Allocate the kmod argument array using kmalloc_array() in preparation
for conversion to type-aware allocators.
- Clean up includes in linux/kmod.h
Add explicit includes of linux/umh.h to files that use usermode
helpers. Then clean up the #include list in linux/kmod.h, notably
removing the compatibility linux/umh.h include.
- Remove the error-injection.h include from linux/module.h
Add explicit includes of linux/error-injection.h to files that use
the ALLOW_ERROR_INJECTION() macro and currently rely on it being
provided indirectly via linux/module.h. Then remove the unnecessary
linux/error-injection.h include from linux/module.h.
- Replace __MODULE_STRING() with __stringify() in various drivers in
preparation for removing the former macro.
* tag 'modules-7.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/modules/linux:
drivers: Replace __MODULE_STRING() with __stringify()
module: Fix uninitialized count read of unloaded taint tracking record
rust: module_param: Fix potentially incorrect access of `SetOnce<T>`
module: Remove the error-injection.h include from linux/module.h
drm/xe: Include error-injection.h for ALLOW_ERROR_INJECTION()
drm/i915: Include error-injection.h for ALLOW_ERROR_INJECTION()
syscalls: Include error-injection.h for ALLOW_ERROR_INJECTION()
net: Include error-injection.h for ALLOW_ERROR_INJECTION()
block: Include error-injection.h for ALLOW_ERROR_INJECTION()
module: Bring includes in linux/kmod.h up to date
time/jiffies: Include linux/sysctl.h for proc_int_u2k_conv_uop(), ...
umh, treewide: Explicitly include linux/umh.h where needed
modules/kmod: Allocate argv with kmalloc_array()
module/kallsyms: Ignore local labels and mapping symbols during module load
module/kallsyms: Refactor current symbol filtering into is_core_symbol()
module/kallsyms: Rename is_mapping_symbol() to is_ignored_kernel_symbol()
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|
check_insane_mems_config() warns and enables cpusets_insane_config_key
when a cpuset's tasks can allocate only from movable memory.
In cgroup v2 the request may name a memoryless node, which has no zones
and cpusets reports it as a movable-only nodemask.
For example, with node 2 a CPU-only node:
# echo +cpuset > /sys/fs/cgroup/cgroup.subtree_control
# mkdir /sys/fs/cgroup/test
# echo 2 > /sys/fs/cgroup/test/cpuset.mems
# cat /sys/fs/cgroup/test/cpuset.mems.effective
0-1
# dmesg
Unsupported (movable nodes only) cpuset configuration detected (nmask=2)!
This is a bit confusing, especially consider mems.effective ends up with
a valid nodemask by-design (cpuset.mems is treated as-if it were empty).
Check each new effective mask in update_nodemasks_hier() instead, as the
hotplug path already does. The allocator's bail-out tests the task's
mems_allowed, which comes from the effective mask.
A request naming a movable-only not present in the parent's nodemask
no longer warns (since, again, the cpuset.mems gets overridden and
treated as empty). However, it will warn if the parent's mems include
the node later.
For Example, with node 3 a movable-only node:
# echo 0 > /sys/fs/cgroup/test/cpuset.mems
# echo 3 > /sys/fs/cgroup/test/child/cpuset.mems
# cat /sys/fs/cgroup/test/child/cpuset.mems.effective
0
# dmesg
{ empty }
# echo 0,3 > /sys/fs/cgroup/test/cpuset.mems
# cat /sys/fs/cgroup/test/child/cpuset.mems.effective
3
# dmesg
Unsupported (movable nodes only) cpuset configuration detected (nmask=3)!
Fixes: 8ca1b5a49885 ("mm/page_alloc: detect allocation forbidden by cpuset and bail out early")
Signed-off-by: Gregory Price (Meta) <gourry@gourry.net>
Reviewed-by: Waiman Long <longman@redhat.com>
Reviewed-by: Ridong Chen <ridong.chen@linux.dev>
Signed-off-by: Tejun Heo <tj@kernel.org>
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|
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
- "selftests/mm: improve khugepaged coverage" (Kiryl Shutsemau):
Give khugepaged a proper workout. Extend the tests to all supported
mTHP orders, check exactly which windows collapsed, and make scan
completion deterministic. Race collapse against faults, pinning, fork
and remap; verify that the contents survive.
Add coverage for whole-page-table zaps and memory pressure too.
- "selftests/mm: separate GUP microbenchmarking from functional testing"
(Sarthak Sharma):
Untangle GUP benchmarking from correctness testing. Move the
benchmark into tools/mm, add a standalone harness-based GUP selftest,
and move shared helpers into tools/lib/mm. Give each tool one job
instead of mixing timing measurements with correctness checks.
Cover the mapping, pinning and batch-size combinations explicitly.
- "mm: Switch device DAX to section-based vmemmap optimization" (Muchun
Song):
Apply section-based vmemmap optimization to device DAX. Rework the
backing metadata layout to save memory while preserving the handling
of device memory hotplug and its different alignment and lifetime
requirements.
- "mm: Introduce section-based vmemmap optimization for HugeTLB"
(Muchun Song):
Cut the memory consumed by HugeTLB's struct page array with
section-based vmemmap optimization. Arrange the metadata so large
huge pages need fewer backing pages, while keeping initialization,
teardown and the various hugepage configurations straight.
- "mm/huge_memory: clean up and decouple the anon and file split
helpers" (Kairui Song):
Separate anonymous and file-backed folio splitting, which have rather
different locking and bookkeeping requirements. Move the work into
separate helpers, drop dead checks and tidy swap-cache handling. Fix
error paths, including one that could leave a folio frozen.
Keep the swap cache cases separate from file-cache splitting.
- "mm: Unconditional per-VMA locks and cleanups" (Dave Hansen):
Make per-VMA locking unconditional and clean up the old conditional
code around it. This removes configuration-dependent plumbing and
lets callers depend on one locking model rather than carrying both
cases along.
- "memcg: remove the v1 soft limit" (Shakeel Butt):
Remove the old cgroup v1 memory soft-limit machinery. This has long
since been superseded by the newer memory-control interfaces; hauling
around a separate reclaim scheme for it no longer buys us much.
- "read proc/pid/smaps_rollup under per-vma lock" (Suren Baghdasaryan):
Read /proc/PID/smaps_rollup using per-VMA locks where possible,
rather than holding mmap_lock across the entire walk. Retain the
contention fallback and add tearing tests. This considerably reduces
latency when another thread is busy changing its mappings.
- "mm/damon: introduce data access-as-a-data attribute" (SJ Park):
Teach DAMON to expose memory access observations as data attributes,
making them available to the probe and filtering machinery. Extend
the interfaces, documentation and tests so the new information can be
used rather than merely collected.
- "Remove PG_private by using page/folio->private checks instead" (Zi
Yan):
Get rid of PG_private and use the folio's private pointer to say
whether private data is attached. Convert the filesystem users,
including erofs, f2fs and md, and clean up the old accessors and
flags. There are a few special cases, notably swapcache and hugetlb,
which need explicit care.
- "mm: make userland page table freeing RCU-safe" (Lorenzo Stoakes):
Make freeing userspace page tables safe against RCU readers. Sort out
the page-table lifetime and locking rules so walkers cannot stumble
over freed tables while mappings are being torn down.
- "make unused huge shrinker memcg aware" (Qi Zheng):
Make shmem's unused-huge-folio shrinker aware of memory cgroups, so
reclaim can find those folios under the right memcg. Wire up the
per-memcg tracking and its lifetime rules, and give the shrinklist
its own lockdep class to avoid spurious dependency reports.
- "mm: Drop pxd_ERROR()" (Anshuman Khandual):
Remove the old pxd_ERROR() page-table checks and their
architecture-specific baggage. Simplify the common page-table
interfaces and callers now that these checks no longer serve a
useful purpose.
- "memcg: group struct fields by access pattern" (Shakeel Butt):
Rearrange memcg's hot and cold fields according to how they're
actually accessed. Keep frequently updated counters and their
neighboring state from fighting over cachelines and reduce needless
cacheline traffic.
- "mm/damon/core: fix the size charged for a filter-trimmed region"
(Donggeun Yoo):
Fix DAMOS quota accounting when a filter trims a monitoring region.
Charge only the part left after filtering, not the original region,
and add KUnit coverage. Previously the excluded memory could eat into
the quota and make schemes run more slowly than requested.
- "mm/damon: add kunit and selftests for probes and probe weights" (SJ
Park):
Add more tests for DAMON probes and their weights, including
validation and the results reported to userspace. This is mostly
about catching regressions in the newer probe infrastructure before
they become harder to diagnose.
- "mm: memcontrol: constify the read side of the read side of the memcg
API" (Tal Zussman):
Mark the read-only parts of the memcg interface const, from folio and
lruvec accessors to counters and swap helpers. Most of this is
mechanical, but it makes the contracts clearer and lets the compiler
catch accidental writes.
- "mm/damon/vaddr: support {prep,apply}_probes" (SJ Park):
Support the new prepare/apply probe operations in DAMON's
virtual-address backend. This brings vaddr monitoring into line with
the probe infrastructure and makes the added probe types useful there
too.
- "mm/mglru: clean up folio counters and flag usage" (Kairui Song):
Simplify MGLRU's folio counters and flag handling. Remove redundant
accounting paths and make the state transitions easier to follow
without changing the intended reclaim policy.
- "arch, mm/execmem: resolve confusion about set_direct_map_valid_noflush()"
(Mike Rapoport (Microsoft)):
Clarify and straighten out the set_direct_map_valid_noflush()
interface across architectures and execmem. Make the requested
mapping changes and the callers' expectations agree, rather than
relying on subtly different architecture behavior.
- "mm: zswap: free cold writeback folios promptly" (Alexandre Ghiti):
Free zswap writeback folios as soon as their disk write completes.
They are cold temporary buffers, so putting them on the LRU only
makes reclaim rediscover them later. Extend swap-cache dropbehind and
let zswap keep these folios off the LRU altogether.
- "mm: gup: cleanup gup_fast call chain" (Aristeu Rozanski):
Clean up the GUP-fast call chain and simplify how the fast-path
helpers pass their arguments and results around. Keep the page-pin
behavior the same while making the call sequence easier to maintain.
- "mm: optimize zone-device memmap initialization" (Li Zhe):
Speed up initialization of zone-device struct pages. Avoid redundant
work when setting up large device-memory ranges, where touching every
descriptor can get expensive.
- "mm/zswap: shrink zswap_entry via a pool id" (Jianyue Wu):
Reduce the size of zswap_entry by storing a compact pool identifier
instead of a full pointer. Keep the pool lookup and lifetime handling
correct while saving per-entry metadata.
- "mm/damon: support access monitoring of hugetlb-backed memory"
(Krishna Iyer):
Let DAMON monitor hugetlb-backed memory too. Extend the relevant
access checks and add coverage so those mappings no longer fall
through a hole in the monitoring machinery.
- "mm/execmem: fixes and cleanups for the ROX cache" (Mike Rapoport):
Tidy execmem's read-only-executable cache and fix its handling of the
awkward allocation and release cases. The aim is to make the cache's
ownership and permission transitions more predictable.
- "zsmallc: remove old object read API" (Sergey Senozhatsky):
Drop zsmalloc's old object-read API and move its remaining users to
the supported access mechanism. This removes a duplicate interface
which we no longer need.
- "mm/mempolicy: stop copying state in the interleave paths" (Gregory
Price):
Stop copying mempolicy state in the interleave paths when a reference
to the existing policy will do. This avoids extra work and makes the
ownership rules less obscure.
- "mm/mglru: speed up inc_min_seq() and fix cold/hot inversions" (Barry
Song):
Make MGLRU's generation advancement cheaper and fix cases where cold
and hot folios end up in the wrong order. Adjust the counter and list
handling so reclaim doesn't keep passing over the better eviction
candidates.
- "mm: Fix MF_DELAYED handling on memory failure" (Lisa Wang):
Treat MF_DELAYED as a partially completed memory-failure operation,
not an outright failure. Propagate that result correctly through
shmem and the generic handler, fix the extra-reference accounting,
and add tests for the resulting SIGBUS behavior.
- "tools/mm/page_owner_sort: fix --sort, add module filter, improve
usage" (Ye Liu):
Fix page_owner_sort's --sort handling, add module-based filtering and
make the usage output more helpful. This makes the tool less
frustrating when tracking down who is holding on to pages.
- "mm/damon: move damos filter range arguments validation to core" (SJ
Park):
Move DAMOS filter range validation into the core, where all callers
can share it. Also close the sysfs read-twice races which could pass
inconsistent ranges, and add tests for invalid input.
- "mm/damon: misc cleanups" (Zenghui Yu):
Clean up a collection of small DAMON rough edges in the core,
interfaces and tests. No large behavior change here, just simpler
code and fewer opportunities for confusion.
- "mm/damon: cleanup code, add test cases, and update guidances in
docs" (SJ Park):
Clean up DAMON's core and interfaces, add missing test cases and
bring the documentation into line with the code. These changes should
make the newer facilities easier to understand and maintain.
- "mm/damon: introduce hugepage_size probe filter" (SJ Park):
Add a DAMON probe filter for hugepage size. Let users select a range
of folio sizes through sysfs, validate the range and document the new
interface, so monitoring can concentrate on memory backed by the
desired hugepage sizes.
- "selftests/mm: pagemap_ioctl test fixes and cleanups" (Zenghui Yu):
Fix some pagemap ioctl test assumptions and clean up their setup and
reporting. Make failures point to the operation that went wrong
rather than to test harness bookkeeping.
- "mm: avoid large folio splits when swap is unavailable" (Johannes
Weiner):
Avoid splitting large folios merely to attempt swap when no swap
space is available. There is little point paying for an expensive
split when reclaim cannot actually swap the resulting pages out.
- "mm: workingset: fix the shadow node budget under MGLRU" (Hui Zhu):
Fix the workingset shadow-node budget with MGLRU enabled. Keep the
shadow entries within the intended limits so refault tracking does
not quietly consume more metadata than it should.
- "selftests/mm: TAP output and global-state fixes" (Song Hu):
Fix selftests which produce misleading TAP output or fail to restore
global settings after a run. A test ought to leave the system as it
found it, particularly when a whole suite follows behind.
- "mm: remove page_swap_entry()" (Tal Zussman):
Remove page_swap_entry() and convert its remaining users to the folio
and swap-entry helpers. Lose an old page-level interface and make the
swap paths a little more consistent.
- "mm: refactor zonelist constructors and iterators" (Gregory Price):
Refactor the zonelist construction and walk helpers to reduce
duplicated logic. Keep the allocation ordering rules intact while
making it clearer how zones are selected.
- "mm: kmemleak: batch the struct page scan" (Breno Leitao):
Scan adjacent struct pages in batches instead of taking kmemleak_lock
once for every single page. This preserves scan coverage and the
lock-hold bound, while cutting overhead substantially on debug
kernels.
- "mm/damon: misc improvements in tests and documents" (Zenghui Yu):
Fix some DAMON selftests which leave kdamond running or fail under
Python safe-path mode, and improve the KUnit coverage and
documentation. Nothing especially glamorous, but these are worth
doing.
- "mm/damon: introduce probe_hits_wsum DAMOS core filter" (SJ Park):
Add a DAMOS core filter using weighted probe-hit counts. This gives
schemes another way to select regions based on what the monitoring
probes observed.
- "mm/mglru: fix ineffective memory protection for non-kswapd reclaim"
(Ridong Chen):
Fix MGLRU's memory protection handling for reclaim outside kswapd.
The protection settings weren't having the intended effect in these
paths, leaving protected memory more exposed than requested.
- "mm/damon: improve readability, clarity and test coverage" (SJ Park):
Simplify a handful of DAMON core helpers, clarify their behavior and
expand test coverage. There are no intended userspace-visible changes
in this batch.
- "mm: replace PF_KCOMPACTD/PF_KSWAPD with kthread_func()" (Kefeng
Wang):
Stop identifying reclaim and compaction workers through the PF_KSWAPD
and PF_KCOMPACTD task flags. Use their kthread functions instead and
remove the redundant flag plumbing.
- "mm/hugetlb: fix surplus accounting and availability checks during
demotion" (Longlong Xia):
Fix HugeTLB surplus accounting and availability checks when demoting
huge pages. Keep the counters and reservation decisions consistent as
one huge page turns into several smaller ones.
- "mm/damon: add kunit tests for probe_hits handling and probe params
validation" (Jason Angelov):
Add KUnit tests for DAMON probe-hit handling and invalid probe
parameters. These cover edge cases that were too easy to miss in
ordinary monitoring tests.
- "mm/damon: fix misc bugs in kunit, quota goals and sysfs refresh_ms"
(SJ Park):
Fix a few DAMON bugs in KUnit tests, quota-goal handling and the
sysfs refresh interval. Small fixes, but the incorrect results and
control behavior were real.
- "mm: zswap: optimize zswap invalidate and store" (Kefeng Wang):
Simplify zswap's invalidate and store paths to avoid avoidable
lookups and work. Keep the entry lifetime rules intact while making
those frequent operations cheaper.
- "mm: replace custom ratelimiting logic" (Pedro Falcato):
Replace hand-rolled MM rate limiting with the common kernel helpers.
There is no need to maintain another local version of the same
mechanism.
- "mm/vmalloc: minor cleanups" (Ye Liu):
Tidy some vmalloc initialization and reporting code, and pull
duplicated vmap-area insertion work into a helper. No functional
changes are intended.
- "mm/mglru: clean up isolate_folios for readability and clarity"
(Ridong Chen):
Clean up MGLRU's isolate_folios() so the decisions are easier to read
and verify. Keep reclaim behavior unchanged while removing
unnecessary twists in the control flow.
- "Catch automatic storage in IDA and Maple Tree definitions" (Yury
Norov):
Catch IDA and maple-tree definitions placed in automatic storage
where the lifetime rules are wrong or easy to get wrong. Add checks
so such mistakes are harder to slip through unnoticed.
- "mm, swap: some random fixes and cleanups" (Kemeng Shi):
Fix and simplify a few unrelated swap paths, removing redundant work
and tidying up error handling. A small collection of things which
were better fixed than left lying around.
- "mm/page_io: folio conversion cleanups" (Tal Zussman):
Finish some page-to-folio conversions in swap I/O, removing obsolete
wrappers and using folio operations consistently. The I/O behavior is
intended to remain the same.
- "mm/swap: skip empty clusters in the swapoff scan" (Youngjun Park):
Skip empty swap clusters during swapoff instead of walking slots
which have nothing to release. This avoids pointless work on sparsely
used swap devices.
- "mm: trace: decode architecture-specific VMA flags" (Meijing Zhao):
Teach the VMA trace output to decode architecture-specific flags,
rather than leaving them as unexplained bits. That should make
tracing a good deal more useful when debugging unusual mappings.
- "mm, swap: don't spin on a bad swap entry" (Breno Leitao):
Stop repeatedly retrying a swap entry which is already known to be
bad. Make the error path terminate cleanly instead of wasting CPU
chasing an entry that cannot be used.
- "mm/page_isolation: fix UBSAN shift-out-of-bounds in
isolate_single_pageblock" (Qi Xi):
Fix an out-of-range shift in isolate_single_pageblock() and tighten
its associated boundary handling. UBSAN found the issue; the result
should be more robust pageblock isolation.
- "mm: khugepaged: fix tracepoint UAF" (Vernon Yang):
Fix a use-after-free in khugepaged tracepoint handling. Make sure the
information recorded by tracing stays valid for as long as the trace
event needs it.
- "mm/damon: fix DAMOS bugs in core, paddr and vaddr" (SJ Park):
Fix several DAMOS problems across the core and physical- and
virtual-address backends. The changes close error cases and bring the
implementations back into agreement.
- "mm/hugetlb_cgroup: move the per-node usage along with the folio"
(Hongfu Li):
Move HugeTLB per-node usage accounting when folios migrate between
nodes or are reparented to another cgroup. Otherwise numa_stat can
retain stale charges and even underflow when the folio is freed.
- "docs/core-api: memory-allocation: add k[mz]alloc_obj() and clarify
kmalloc" (Mike Rapoport):
Document the typed k[mz]alloc_obj() allocation helpers and clear up
some kmalloc guidance. Make it easier for callers to choose the right
interface.
- "selftests/mm: Validate selections and scope memfd_secret setup"
(Tianyi Chen):
Check selftest selections before running and confine memfd_secret
setup to the cases that actually need it. Avoid confusing failures
caused by the test harness itself.
- "mm/damon: move zero damos quota target_value handling to the core
layer" (SJ Park):
Handle a zero DAMOS quota goal target in the core rather than making
each user of the interface invent its own rule. Keep quota decisions
consistent across callers.
- "mm/damon: Introduce a huge page collapsing mechanism using auto
tuning" (Asier Gutierrez):
Add an auto-tuned DAMON mechanism for collapsing huge pages. Use
monitoring feedback to decide when collapse is worthwhile rather than
forcing one fixed policy onto every workload.
- "kmemleak: fix stale documentation and raise the verbose default"
(Breno Leitao):
Bring the kmemleak documentation up to date and require a third
confirming scan before verbose kernels print a suspected leak. The
extra scan helps suppress transient false positives in noisy debug
builds.
- "mm/memory: improve insert_pages() error handling" (Avi Weiss):
Tighten insert_pages() error handling so partial failures are
reported and cleaned up consistently. The caller should not have to
guess how far the operation got.
- "mm/damon: allow NULL or unstarted damon_ctx parameter for
damon_call()" (SJ Park):
Make damon_call() handle NULL and not-yet-started contexts safely.
Simplify the rules for callers and avoid an indefinite wait on an
invalid state.
- "mm/damon: introduce pgidle_set probe filter type" (SJ Park):
Add a pgidle_set DAMON probe filter, giving monitoring users another
way to select pages by their idle-tracking state. Wire it through the
filter interfaces and tests.
- "mm/damon/core: remove unused helper functions" (Cheng-Han Wu):
Remove DAMON core helpers which no longer have callers. Keep the API
surface smaller rather than retaining dead code just in case.
- "mm: stop calling pmd_folio() on special PMDs" (Gregory Price):
Avoid calling pmd_folio() on special PMD mappings that have no struct
page. The old assumption could fault in procfs walkers; use the
normal-folio checks and handle those mappings properly.
- "mm: remove three unused helpers from mm.h" (Tal Zussman):
Remove three unused helpers from mm.h. Fewer obsolete interfaces for
the next person to stumble over.
- "mm/damon: improvements in efficiency, error handling, documents"
(Liew Rui Yan):
Skip needless DAMOS quota work once the quota is full, propagate a
missing sysfs error and tidy a couple of comments. The ignored error
could make a monitoring-start request appear successful when it
wasn't.
- "docs/mm/damon/design: add explanation of nr_snapshots" (Liew Rui
Yan):
Explain DAMON's nr_snapshots accounting in the design documentation
and straighten out the associated terminology. Make it clearer what
users should expect from that counter.
- "selftests/cgroup: fixes for test_zswap on single core VM" (Wilson
Felipe Pereira):
Fix two test_zswap failures on single-CPU VMs. Wait for the exiting
child's cgroup to become unpopulated before reconfiguring it, and
avoid another test assumption which breaks under constrained
scheduling.
- "docs/ksm: fix advisor documentation and comment" (Jinjiang Tu):
Correct the KSM advisor documentation and a misleading code comment.
Keep the description aligned with how the advisor actually works.
- "Fix bugs in HugeTLB allocation when mem_cgroup_charge_hugetlb()
fails" (Ackerley Tng):
Fix HugeTLB allocation cleanup when the memcg charge fails. Make sure
failure exits undo what was allocated rather than leaving stale
accounting or resources behind.
- "mm, memcg: fix memory.peak reset clobbering other fds' watermark"
(Ridong Chen):
Fix memory.peak reset handling so resetting one file descriptor
doesn't overwrite the watermark kept for another. Keep those per-open
measurements independent as intended.
- "mm: reject zone device folios in more folio walkers" (Gregory
Price):
Reject zone-device folios in page walkers that cannot safely handle
them. Extend the existing checks rather than assuming every folio has
ordinary system-memory backing.
- "percpu: remove code with no effect" (Sang-Heon Jeon):
Remove a few pieces of percpu code which no longer do anything. There
is no reason to keep maintaining dead paths.
* tag 'mm-stable-2026-10-19-21-33' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (539 commits)
mm: shmem: assign a lock class to the unused huge shrinklist
mm: vmscan: put rotation-missed folios at the LRU tail
mm: kmemleak: scan the struct page array in MAX_SCAN_SIZE batches
mm: kmemleak: move the struct page scan into a helper
mm/damon: document that a zero sample_interval is accepted
mm/damon: fix typos in comments
mm/damon/sysfs: propagate damon_call() error in turn_damon_on
mm/damon/core: skip quota score setup when the quota is full
mm/damon/tests/core-kunit: test the size charged for a filter-trimmed region
mm/damon/core: charge only the part of a region the filter left
mm: disallow raw PFN mappings of huge/shared zeropage
selftests/mm: zap whole PTE tables in the khugepaged race harness
selftests/mm: add memory-pressure threads to the khugepaged race harness
selftests/mm: race the collapse of windows with holes
selftests/mm: add khugepaged race harness
selftests/mm: check that one khugepaged pass collapses one window
selftests/mm: run every supported collapse order by default
selftests/mm: cover a shared-source collapse write race
selftests/mm: parameterize the mixed-source collapse case by source order
selftests/mm: add order-parameterized khugepaged collapse cases
...
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Creating a child partition can fail when tasks are present in its
descendants, even though the parent has no tasks of its own.
On a cgroup v2 system with CPUs 0-7 online:
cd /sys/fs/cgroup
echo +cpuset > cgroup.subtree_control
mkdir A
echo 1-2 > A/cpuset.cpus
echo root > A/cpuset.cpus.partition
echo +cpuset > A/cgroup.subtree_control
mkdir A/B
echo 1-2 > A/B/cpuset.cpus
echo +cpuset > A/B/cgroup.subtree_control
mkdir A/B/C
echo 1-2 > A/B/C/cpuset.cpus
echo $$ > A/B/C/cgroup.procs
echo root > A/B/cpuset.cpus.partition
cat A/B/cpuset.cpus.partition
root invalid (Parent unable to distribute cpu downstream)
cat A/cpuset.cpus.effective
1-2
B should be a valid root, leaving A with an empty effective CPU list.
The task in C belongs to B's partition and does not need CPUs in A.
partition_is_populated() is called with B as excluded_child, but
continue only skips B in the pre-order walk. The walk still visits C
and finds the task there, so A is considered populated.
Fix this by skipping the whole excluded subtree with
css_rightmost_descendant(), as is already done for valid child
partitions. Also add a test case to test_cpuset_prs.sh with a task in
a grandchild cpuset.
Fixes: b1bcaed1e39a ("cpuset: Treat cpusets in attaching as populated")
Cc: stable@vger.kernel.org # v6.19+
Signed-off-by: Guopeng Zhang <zhangguopeng@kylinos.cn>
Reviewed-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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With favordynmods enabled, a cgroup.procs migration takes the target
threadgroup's cgroup_threadgroup_rwsem for writing. A process fork holds
the forking threadgroup's semaphore for reading. These are different
semaphores when fork creates a new process.
copy_process() publishes the child's PID before cgroup_post_fork() links
the child to its css_set. A writer can find the child in that interval,
take its uncontended semaphore, and migrate it while child->cgroups still
points to init_css_set and child->cg_list is empty. Migration links the
node into init_css_set.mg_tasks. cgroup_post_fork() then adds the same
node to the intended css_set as though it were unlinked, corrupting both
task lists and their css_set ownership.
This regresses the fork/migration race fixed by commit b12b533fa523
("cgroups: add lock for child->cgroups in cgroup_post_fork()") and
restored again in 2012 after the lock had been removed. The old task_lock
protection was later superseded by global css_set and cgroup threadgroup
locking. The change identified by the Fixes tag narrowed only the migration
side back to a per-threadgroup lock, recreating the different-process
exclusion failure.
Take the new threadgroup's semaphore for reading before the child becomes
visible and hold it through cgroup_post_fork(). Use a nested lock subclass
because fork already holds the parent's semaphore. CLONE_THREAD children
share the parent's signal_struct and remain covered by the existing lock.
Migrations of unrelated, fully initialized threadgroups remain concurrent.
An AI coding assistant was used to identify and reproduce the regression
and to develop and test this fix.
Fixes: 0568f89d4fb8 ("cgroup: replace global percpu_rwsem with per threadgroup resem when writing to cgroup.procs")
Cc: stable@vger.kernel.org # 6.18+
Signed-off-by: Daehyeon Ko <4ncienth@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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cgroup.kill does not work in case a process' thread group leader is gone
but other threads are still running. This is because __cgroup_kill()
only walks the thread group leaders and sends SIGKILL to each of them
with send_sig(), which uses PIDTYPE_PID:
1. The exited leader is still listed by CSS_TASK_ITER_PROCS as long as
the process has live threads, but a signal directed at a single
exiting task never takes effect: complete_signal() does not look for
another thread to deliver it to, and __send_signal_locked() now drops
it altogether. The process keeps running.
2. The live threads of such a process can be migrated to another cgroup
by writing any of their IDs to cgroup.procs, while the exited leader
stays behind. The destination cgroup has no thread group leader to
iterate, so writing to its cgroup.kill does nothing at all.
In both cases the cgroup stays populated after cgroup.kill, and a
process inside a container can use this to survive the container being
killed. This also works with a private PID namespace when the init of
the container is the process, as the PID namespace is not torn down
while init has live threads.
Case 1 can be fixed by using do_send_sig_info(..., PIDTYPE_TGID) instead
of send_sig(), so that the signal is taken by a live thread even if the
task found by the iterator is exiting. Note it was pointed out by Eric
in [1] while reviewing v2 of cgroup.kill patchset, and v3 was meant to
switch to it, but the change was only made in cgroup_post_fork(),
leaving __cgroup_kill() with send_sig().
Case 2 can only be fixed by iterating over all threads, so this is what
the fix also does. Once a thread group is being killed, its other
threads are skipped since they already have a fatal signal pending.
I ran some performance checks and the added cost is ~60 ns per every
thread on my laptop (and less than a millisecond for 10K threads),
which seems low. The time to "populated 0" seems unchanged.
The issue was found in crun by Anthropic's OSS Scanner, and crun is
getting a workaround for it [2] (which does what we needed to do
before cgroup.kill was added).
[1] https://lore.kernel.org/all/m1v97x6niq.fsf@fess.ebiederm.org/
[2] https://github.com/containers/crun/pull/2351
Fixes: 661ee6280931 ("cgroup: introduce cgroup.kill")
Cc: stable@vger.kernel.org # v5.14+
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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Although it is not typical for real users to create a complicated nested
partition hierarchy, it is currently allowed to create nested root and
isolated partitions. In addition, disabling or invalidating a partition
should always be allowed especially when the cpuset is being deleted.
With a nested root and isolated partition hierarchy, it is possible
that all active housekeeping CPUs can be exhausted when disabling or
invalidating a root partition and returning its CPUs to the isolated
parent.
One way to avoid this problem is to disallow the creation of a root
partition under an isolated parent. It is indeed a new limitation imposed
on the existing cpuset partition functionality. However an isolated
partition is usually a left node where scheduling and some other kernel
noises are disabled. It doesn't make much sense to create a child root
partition under an isolated parent and remove some CPUs from the set
of isolated CPUs again. Creation of a child isolated partition under a
root or isolated parent is still allowed.
If a partition with child root partitions is converted to isolated,
the child root partitions will be invalidated.
The cgroup-v2 documentation is also updated to reflect this new
limitation. New test cases are added to test_cpuset_prs.sh to verify
this new behavior. Some existing test cases are also updated accordingly.
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
|
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Before commit 103b08709e8a ("cgroup/cpuset: Fail if isolated and nohz_full
don't leave any housekeeping"), the partition state can be freely switched
from "root" to "isolated" and vice versa. After that commit, the switch
from "root" to "isolated" can fail if it exhausts all the housekeeping
CPUs. Later on, the switch from "isolated" to "root" can also fail if
some of the partition CPUs are boot-time isolated by "isolcpus".
A local or remote partition is made invalid when the switch fails.
However there are 2 problems with the existing invalidation code.
1) Both the subpartitions_cpus and isolated_cpus are not properly
updated.
2) In the case of remote partition with remote_partition flag set, it
is not cleared.
Fix this by calling the proper partition disabling function in this case.
On an x86 test system with boot option "isolcpus=10 cgroup_debug" set
and more than 16 cores, the following commands were executed after boot.
# cd /sys/fs/cgroup
# echo +cpuset > cgroup.subtree_control
# cat cpuset.cpus.isolated
10
# mkdir A
# echo 10-12 > A/cpuset.cpus
# echo isolated > A/cpuset.cpus.partition
# cat A/cpuset.cpus.partition
isolated
Before the patch:
# echo root > A/cpuset.cpus.partition
# cat A/cpuset.cpus.partition
root invalid (partition config conflicts with housekeeping setup)
# cat cpuset.cpus.isolated .__DEBUG__.cpuset.cpus.subpartitions
10-12
10-12
After the patch:
# echo root > A/cpuset.cpus.partition
# cat A/cpuset.cpus.partition
root invalid (partition config conflicts with housekeeping setup)
# cat cpuset.cpus.isolated .__DEBUG__.cpuset.cpus.subpartitions
10
Reported-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/lkml/7f4c57b26ad120ab30adf35653f1dd94@kernel.org/
Fixes: 4a74e418881f ("cgroup/cpuset: Check partition conflict with housekeeping setup")
Fixes: 103b08709e8a ("cgroup/cpuset: Fail if isolated and nohz_full don't leave any housekeeping")
Reviewed-by: Guopeng Zhang <zhangguopeng@kylinos.cn>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
|
|
valid
When a hotplug event happens or when update_cpumasks_hier() is called, an
invalid partition may be converted back to valid. However check against
housekeeping conflict isn't being done which can lead to a partition
state that violates the housekeeping rules. Update the code to allow
reviving an invalid partition only if it can pass the housekeeping check.
Fixes: 4a74e418881f ("cgroup/cpuset: Check partition conflict with housekeeping setup")
Reviewed-by: Guopeng Zhang <zhangguopeng@kylinos.cn>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
|
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When prstate_housekeeping_conflict() is called to perform housekeeping
check with cpumask changes, the cpumask changes are passed in via add_cpus
and del_cpus parameters. With this arrangement, the exclusive CPUs owned
by the child partitions and not affected by the cpumask change, if any,
are excluded in the analysis. The only places where there are separate
add and delete masks are when the cpuset.cpus or cpuset.cpus.exclusive
is being changed. In both cases, partition_cpus_change() is a good place
to perform the housekeeping check.
If we allow a root partition to be created under an isolated partition,
it is possible the cpumask change will still leave active housekeeping
CPUs but then no housekeeping CPUs will be left when the child partitions
are disabled or invalidated.
As a first step to protect against this possibility, all the exclusive
CPUs of the cpuset should be considered to be owned by the current cpuset
when doing housekeeping check. At the same time, we do want to know if
some housekeeping CPUs are going to be removed from the isolated partition
that there will be no danger of losing all the active housekeeping CPUs.
So the current add_cpus paremeter is renamed as new_cpus to indicate
that it includes the complete set of effective xcpus.
With the new check in partition_cpus_change(), the housekeeping check
in update_parent_effective_cpumask() with partcmd_update and newmask
is now duplicative and can be removed. The housekeeping check in
remote_cpus_update(), however, will still be useful as this function can
be called directly from update_cpumasks_hier() without going through
partition_cpus_change(). The update_parent_effective_cpumask() call
from update_cpumasks_hier() is partcmd_update with no cpumask which
still have the housekeeping check and so is covered.
Fixes: 103b08709e8a ("cgroup/cpuset: Fail if isolated and nohz_full don't leave any housekeeping")
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
|
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prstate_housekeeping_conflict()
The isolated_cpus_can_update() and prstate_housekeeping_conflict() are
checking different aspects of upcoming cpumask changes that may conflict
with the current setting of the housekeeping cpumasks. There are places
where both are called together. There are also places where only one
of them is called. That inconsistency can contribute to missing check
where invalid cpumask changes may be allowed to move forward.
Fix that by consolidating isolated_cpus_can_update() into
prstate_housekeeping_conflict() and call prstate_housekeeping_conflict()
in all the places where either one of them or both are called. The
exception is the validate_partition() function where the
prstate_housekeeping_conflict() call is removed. It is because
validate_partition() is called only from partition_cpus_change()
where prstate_housekeeping_conflict() will be called from either
remote_cpus_update() or update_parent_effective_cpumask() with
partcmd_update if not for partition invalidatation or disablement.
Now prstate_housekeeping_conflict() will be called in the following
locations:
- when a partition is enabled in remote_partition_enable() or in
update_parent_effective_cpumask() with partcmd_enable*.
- when a cpumask is updated in remote_cpus_update() or in
update_parent_effective_cpumask() with partcmd_update.
- when a partition state changes from root to isolated or vice versa
in update_prstate().
Fixes: 4a74e418881f ("cgroup/cpuset: Check partition conflict with housekeeping setup")
Fixes: 103b08709e8a ("cgroup/cpuset: Fail if isolated and nohz_full don't leave any housekeeping")
Reviewed-by: Guopeng Zhang <zhangguopeng@kylinos.cn>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
|
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It is found that when a local isolated partition is being invalidated
because its parent partition is no longer valid, the isolated_cpus
cpumask may not be properly updated. Those isolated CPUs may or may
not needed to be removed from isolated_cpus depending on if there is
a local isolated partition ancestor that will now own those isolated
CPUs instead.
Fix that by calling a new ancestor_partition() helper to return the
closeset valid partition root ancestor. If that ancestor is PRS_ROOT,
the isolated CPUs will have to be removed from isolated_cpus. For
a PRS_ISOLATED ancestor, the isolated CPUs are checked against
the ancestor's ones to see if any of them should be removed as it is
possible that the invalidation of the parent may be caused by change in
the effective xcpus of that ancestor. If any of the isolated CPUs should
be removed, isolated_cpus_update() will be called under callback_lock.
An existing test case in test_cpuset_prs.sh is modifed and a new one
added to test that.
Fixes: 11e5f407b64a ("cgroup/cpuset: Keep track of CPUs in isolated partitions")
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
|
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A cpuset update changes the task's mems_allowed and rebinds its
mempolicy in separate steps under mems_allowed_seq, but the check
reads both without it. This can cause a spurious numa placement
miss under some cpuset/mempolicy combinations.
A reader that loads one mask before the update and the other after
it can see a spurious empty intersection and drop the nodemask.
For example, a task with cpuset.mems={0} and MPOL_BIND={0}. If the
cpuset moves to mems={1,2}, the policy is rebound to {1}.
The allocator can race and compare the old mems_allowed {0} against
the new policy {1} - which will result in a dropped nodemask and a
misplaced allocation on node 2.
Simply retry the intersection until mems_allowed_seq is stable.
This covers the task policy, which is rebound under mems_allowed_seq.
VMA policies are rebound afterwards by mpol_rebind_mm(), outside
mems_allowed_seq, and are not covered by this change.
Fixes: cc9a6c877661 ("cpuset: mm: reduce large amounts of memory barrier related damage v3")
Reviewed-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Reviewed-by: Waiman Long <longman@redhat.com>
Signed-off-by: Gregory Price (Meta) <gourry@gourry.net>
Signed-off-by: Tejun Heo <tj@kernel.org>
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Pull to receive 1765a153d985 ("cgroup/pids: Restore pids.events
notifications in local mode") for the pids.events notification
selftest.
Signed-off-by: Tejun Heo <tj@kernel.org>
|
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Linux 7.3-rc6
This was requested by Thomas to have a new base to start some branch from
Signed-off-by: Dave Airlie <airlied@redhat.com>
|
|
memcg_vmstats keeps a non-hierarchical copy of every memcg-wide stat item
and event alongside the hierarchical one. The only readers however are
the legacy memory.stat and memory.numa_stat, and reparenting on offline.
All of them live under CONFIG_MEMCG_V1, and their accessors
(memcg_page_state_local() and memcg_events_local()) are already compiled
out with it. This means on a CONFIG_MEMCG_V1=n kernel, memcg_vmstats's
non-hierarchical arrays are written to on every rstat flush, despite their
values never being read / accessed.
The same holds when the kernel does support v1 but the controller has been
blocked from v1 hierarchies with the boot param cgroup_no_v1={memory,all}.
A v1 mount is refused in that case, so the legacy memory.stat can never
exist and the arrays are just as unread / unaccessed.
Compile out the non-hierarchical memcg-wide arrays if CONFIG_MEMCG_V1 is
not set. If it is set but cgroup_no_v1= has blocked the controller, skip
updates on the arrays.
This makes flushes cheaper. mem_cgroup_stat_aggregate() can now skip the
read-modify-write of ac->local[i]. Nothing else accesses state_local or
events_local, so those cachelines were getting pulled in solely for the
writes and they are separate from the ones the loop is already walking.
On an 80-cpu x86_64 machine with 500 cgroups each running a workload that
dirties anon, file, dirty/writeback, slab, kmem, mlock, and reclaim
counters, timing mem_cgroup_css_rstat_flush() in-kernel in TSC ticks per
flush showed roughly
before after delta
memcg-wide aggregation 1231 1180 -4.1%
overall flush function 2452 2397 -2.2%
These numbers are from taking the median of 70 samples, one per 20s window
on each kernel. The 95% intervals observed on the two deltas are [-5.41%,
-1.76%] and [-4.53%, -0.14%]. The values above include the timing
overhead itself, so only the delta is meaningful here.
Counting the items that actually changed, a median of 1.5 of the 77
memcg-wide items (57 state + 20 events) had a non-zero per-cpu delta at
each flush, which means the benchmarks above are with one or two fewer
cachelines pulled in per flush. The count is low because the benchmark
reads memory.stat in a loop to keep the flush rate up. For cases where
flushes are triggered only by the 2s periodic worker, more changes will
have accumulated between flushes, so more cachelines are skipped and the
per-flush saving should be larger.
Link: https://lore.kernel.org/20260903215616.1456239-1-joannelkoong@gmail.com
Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: Yosry Ahmed <yosry@kernel.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
|
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cpuset_handle_hotplug()
It is reported by sashiko that calling is_in_v2_mode() outside of
cpuset_mutex critical section in cpuset_handle_hotplug() can introduce
a TOCTOU race where cgroup hierarchy may have changed from v1 to v2 or
vice versa after is_in_v2_mode() is called leading to erroneously skip
the allocation of tmpmasks or incorrectly modify cpus_allowed masks,
resulting in cpuset state corruption. Fix that by calling is_in_v2_mode()
after acquiring the cpuset_mutex.
Fixes: b8d1b8ee93df ("cpuset: Allow v2 behavior in v1 cgroup")
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
|
|
With commit 2125c0034c5d ("cgroup/cpuset: Make cpuset hotplug processing
synchronous"), the cpuset hotplug operation becomes synchronous. That
commit also removes the code that handles race between cpuset_hotplug_work
and cpu hotplug notifier with the assumption that race is now gone.
Later commit 7a0aabd9ce69 ("cgroup/cpuset: Always use cpu_active_mask")
updates the cpuset code to always use cpu_active_mask instead of
cpu_online_mask in some places including guarantee_online_cpus() which
is renamed to guarantee_active_cpus() in that commit.
In the case of CPU offline operation, cpu_active_mask is updated
first in sched_cpu_deactivate() to remove the offline CPU before
cpuset_handle_hotplug() is called to update the effective_cpus of the
affected cpusets. The cpu_online_mask is updated after that near the end
of the offline operation to remove the offline CPU. As a result, the race
comes back and the top cpuset may not have any active CPU leading to NULL
pointer dereference during the race window when guarantee_active_cpus()
is called after cpu_active_mask is updated to remove the CPU to be torn
down but before cpuset_handle_hotplug() is able to properly update the
effective_cpus of the top cpuset.
Fix this by adding back the NULL cs check to avoid this problem.
Fixes: 7a0aabd9ce69 ("cgroup/cpuset: Always use cpu_active_mask")
Cc: stable@vger.kernel.org # v6.16+
Reported-by: Farhad Alemi <farhad.alemi@berkeley.edu>
Link: https://lore.kernel.org/lkml/CA+0ovChh3VjsKN1g+ZGjwwY2fGTpP7uD+aCCByLj5Qbymw=bfQ@mail.gmail.com
Signed-off-by: Waiman Long <longman@redhat.com>
Tested-by: Farhad Alemi <farhad.alemi@berkeley.edu>
Signed-off-by: Tejun Heo <tj@kernel.org>
|
|
cgroup_e_css() and cgroup_get_e_css() find the effective css by walking
up the hierarchy until they reach a cgroup that has the subsystem
enabled. Per-I/O users such as nvmet need this lookup to be O(1).
Track the effective css in each cgroup and make cgroup_e_css() and
cgroup_get_e_css() use it. When a css is brought online or offline,
update the effective css of its cgroup and of all descendants.
Signed-off-by: Peng Yu <yupeng0921@gmail.com>
Assisted-by: Claude:claude-fable-5 [Claude Code]
Assisted-by: Claude:claude-opus-5-5 [Claude Code]
Signed-off-by: Tejun Heo <tj@kernel.org>
|
|
cpuset_update_flag() is only used by the legacy (v1) interface: its
callers are the write handlers of cpuset1_files via cpuset_write_u64(),
and cpuset_css_offline() which invokes it only on the legacy hierarchy
(!cpuset_v2() && is_sched_load_balance()).
Move it into cpuset-v1.c, where its sole helper
cpuset1_update_tasks_flags() already lives, so both can go back to being
static and drop out of cpuset-internal.h. As a result:
- dup_or_alloc_cpuset(), free_cpuset() and validate_change() are now
referenced from cpuset-v1.c, so they lose their static qualifier and
gain declarations in cpuset-internal.h.
- The v2 branch in cpuset_update_flag() that called
cpuset_force_rebuild() is dead on the v1-only call paths and is
dropped; the remaining rebuild_sched_domains_locked() path is kept.
callback_lock, a static in cpuset.c, is taken through the existing
cpuset_callback_lock_irq() wrapper.
- The open-coded "!cpuset_v2() && is_sched_load_balance()" test in
cpuset_css_offline() is wrapped in a new cpuset1_offline_css() helper
(a no-op stub when CONFIG_CPUSETS_V1=n), removing the last
cpuset_v2() branch from that path in cpuset.c.
No functional change intended.
Assisted-by: LLM
Signed-off-by: Ridong Chen <chenridong@xiaomi.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
|
|
After seeing the patch [1] to guard is_in_v2_mode() with RCU, it makes
me realize that is_in_v2_mode() may be called in a context where a new
cgroup filesystem is being rebound with stale cpuset_cgrp_subsys.root
pointer. Avoid this potential UaF situation by adding a new cpuset_v2_mode
flag which is set when the cpuset_v2_mode mount option is used. This
flag is written into only when cpuset_bind() is being called with a
stable cpuset_cgrp_subsys.root value. The is_in_v2_mode() helper is
modified to read the new cpuset_v2_mode flag instead of accessing
cpuset_cgrp_subsys.root directly.
[1] https://lore.kernel.org/lkml/20260929084124.626693-2-arighi@nvidia.com
Fixes: b8d1b8ee93df ("cpuset: Allow v2 behavior in v1 cgroup")
Signed-off-by: Waiman Long <longman@redhat.com>
Reviewed-by: Ridong Chen <ridong.chen@linux.dev>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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The cpuset code has 2 different helpers for determining if it is in a
v1 or v2 working environment - cpuset_v2() and is_in_v2_mode().
cpuset_v2() checks the binding of the cpuset subsystem is on a v1
or v2 hierarchy. It can also help to optimize out v1 specific code
if CONFIG_CPUSETS_V1 isn't defined.
is_in_v2_mode() layers on top of cpuset_v2() and returns true if it is in
a v2 hierarchy or in a v1 hierarchy with "cpuset_v2_mode" mount option
enabled to make "cpuset.cpus" and "cpuset.mems" behave in a way similar
to their v2 counterparts. However the cpuset hierarchy may still be a
standalone one separated from the other cgroup hierarchies.
Commit 90ac22ffef48 ("sched/fair: Add cgroup_mode: max") adds a new
cpuset_num_cpus() helper to return the number of effective CPUs in a given
cgroup. It is part of the "sched: Flatten the pick" patch series to help
flatten the cpu cgroup runqueue hierarchies. cpuset_num_cpus() currently
uses is_in_v2_mode() to determine if it is in a v2 environment. However
is_in_v2_mode() can be true in a v1 environment where the cpuset and cpu
cgroup subsystems can be in two separate hierarchies. The current use
case [1] for cpuset_num_cpus() assumes that it can return the number
of effective CPUs present in the current cpu cgroup which may not be
the case.
Fix that by switching to use cpuset_v2() which signifies that it is in
a unified hierarchy where both cpuset and cpu cgroup subsystems share
the same cgroup hierarchy if it returns true.
[1] https://lore.kernel.org/lkml/20260930081125.GF88198@noisy.programming.kicks-ass.net
Fixes: 90ac22ffef48 ("sched/fair: Add cgroup_mode: max")
Signed-off-by: Waiman Long <longman@redhat.com>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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As the is_cpu_exclusive() function is only used for DEADLINE shrink
test with v1 there is no need to have the CS_CPU_EXCLUSIVE flag set on
valid partition root anymore. Remove update_partition_exclusive_flag()
and other CS_CPU_EXCLUSIVE flag handling code in cpuset.c.
Signed-off-by: Waiman Long <longman@redhat.com>
Reviewed-by: Ridong Chen <ridong.chen@linux.dev>
Reviewed-by: Guopeng Zhang <zhangguopeng@kylinos.cn>
Signed-off-by: Tejun Heo <tj@kernel.org>
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Commit f82f80426f7a ("sched/deadline: Ensure that updates to exclusive
cpusets don't break AC") adds a check in validate_change() to make
sure that there is enough bandwidth for SCHED_DEADLINE tasks if we
shrink a v1 exclusive cpuset that has CS_CPU_EXCLUSIVE flag set.
With the introduction of cpuset partition in cgroup v2, we keep setting
the CS_CPU_EXCLUSIVE flag for a partition root so that the SCHED_DEADLINE
check will continue to work as intended. However it turns out that the
current code isn't perfect and there are cases where a cpuset isn't
a valid partition root, but the exclusive flag is still incorrectly
set. This can leads to SCHED_DEADLINE check being incorrectly triggered
when there are deadline tasks in the system. This can result in unexpected
-EBUSY failure when making changes to cpuset control files. Fix that
by checking for a valid partition root for v2 and is_cpu_exclusive()
for v1. It is far easier and less cumbersome than to make sure that
the exclusive flag is only set for valid partition roots.
Even though commit a86ce68078b2 ("cgroup/cpuset: Extract out
CS_CPU_EXCLUSIVE & CS_SCHED_LOAD_BALANCE handling") is marked as a
commit to be fixed, the problem may exist before that.
Fixes: a86ce68078b2 ("cgroup/cpuset: Extract out CS_CPU_EXCLUSIVE & CS_SCHED_LOAD_BALANCE handling")
Signed-off-by: Waiman Long <longman@redhat.com>
Reviewed-by: Ridong Chen <ridong.chen@linux.dev>
Reviewed-by: Guopeng Zhang <zhangguopeng@kylinos.cn>
Signed-off-by: Tejun Heo <tj@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fix from Tejun Heo:
- A cpuset partition could claim CPUs an ancestor partition already
held exclusively. Restore the rejection an earlier change had turned
into a warning.
* tag 'cgroup-for-7.3-rc4-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup/cpuset: Return PERR_NOCPUS in remote_partition_enable() on subpartitions_cpus conflict
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subpartitions_cpus conflict
When a remote partition is created underneath an existing local partition
via a non-partition (PRS_MEMBER) intermediate cgroup, update_prstate() sees
parent->partition_root_state == PRS_MEMBER and calls
remote_partition_enable().
Commit 86888c7bd117 ("cgroup/cpuset: Add warnings to catch inconsistency
in exclusive CPUs") replaced the cpumask_intersects(tmp->new_cpus,
subpartitions_cpus) error check in remote_partition_enable() with
WARN_ON_ONCE(). As a result, remote_partition_enable() emits a warning
and proceeds to enable the remote partition on CPUs that are already
owned by the ancestor local partition in subpartitions_cpus.
This can be reproduced on Linux 7.3.0-rc3 with:
mkdir -p /tmp/cg1
mount -t cgroup2 none /tmp/cg1
echo "+cpuset" > /tmp/cg1/cgroup.subtree_control
mkdir /tmp/cg1/A
echo 1 > /tmp/cg1/A/cpuset.cpus
echo 1 > /tmp/cg1/A/cpuset.cpus.exclusive
echo root > /tmp/cg1/A/cpuset.cpus.partition
echo "+cpuset" > /tmp/cg1/A/cgroup.subtree_control
mkdir /tmp/cg1/A/B
echo 1 > /tmp/cg1/A/B/cpuset.cpus
echo 1 > /tmp/cg1/A/B/cpuset.cpus.exclusive
echo "+cpuset" > /tmp/cg1/A/B/cgroup.subtree_control
mkdir /tmp/cg1/A/B/D
echo 1 > /tmp/cg1/A/B/D/cpuset.cpus
echo 1 > /tmp/cg1/A/B/D/cpuset.cpus.exclusive
echo root > /tmp/cg1/A/B/D/cpuset.cpus.partition
which triggers:
WARNING: kernel/cgroup/cpuset.c:1594 at remote_partition_enable+0x1c1/0x300
and leaves both /tmp/cg1/A and /tmp/cg1/A/B/D as active root partitions
claiming exclusive CPU 1.
Fix this by returning PERR_NOCPUS when tmp->new_cpus intersects
subpartitions_cpus in remote_partition_enable(), matching the error code
used by remote_cpus_update() for the same subpartitions_cpus conflict, and
add a regression test case to
tools/testing/selftests/cgroup/test_cpuset_prs.sh.
Tested in QEMU on Linux 7.3.0-rc3 using the reproducer above and
tools/testing/selftests/cgroup/test_cpuset_prs.sh.
Fixes: 86888c7bd117 ("cgroup/cpuset: Add warnings to catch inconsistency in exclusive CPUs")
Suggested-by: Guopeng Zhang <guopeng.zhang@linux.dev>
Cc: stable@vger.kernel.org
Assisted-by: LLM
Signed-off-by: Hui Peng <benquike@gmail.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fixes from Tejun Heo:
- With local event accounting, a fork rejected by the pids controller
updated pids.events without notifying its pollers
- A cgroup selftest failed to compile with fortification enabled
because an O_TMPFILE open lacked its mode argument
* tag 'cgroup-for-7.3-rc4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup/pids: Restore pids.events notifications in local mode
selftests: cgroup: give the O_TMPFILE open in get_temp_fd() a mode
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A fork rejected by the pids controller increments the counter reported by
pids.events. When local event accounting is selected, however, pids_event()
returns after notifying only events_local_file, leaving pids.events pollers
asleep.
On legacy hierarchies, pids.events.local does not exist. With
pids_localevents, pids.events reports the same local counter. In both
cases, pids.events changes without generating a notification.
This can be reproduced with a pids_localevents mount:
mkdir /tmp/test
mount -t cgroup2 -o pids_localevents none /tmp/test
mkdir /tmp/test/t
echo 1 > /tmp/test/t/pids.max
cat /tmp/test/t/pids.events # max 0
timeout 3 inotifywait -e modify /tmp/test/t/pids.events &
sh -c 'echo $$ > /tmp/test/t/cgroup.procs; (true &)' 2>/dev/null
wait
cat /tmp/test/t/pids.events # max 1
Without this patch, inotifywait times out without reporting an event.
Notify pids.events before returning from the local event path.
Fixes: 3f26a885a068 ("cgroup/pids: Add pids.events.local")
Cc: stable@vger.kernel.org # v6.11+
Signed-off-by: Guopeng Zhang <zhangguopeng@kylinos.cn>
Signed-off-by: Tejun Heo <tj@kernel.org>
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The usermode helper declarations were previously provided by linux/kmod.h
but commit c1f3fa2a4fde ("kmod: split off umh headers into its own file")
moved them to linux/umh.h in 2017.
Add explicit includes of linux/umh.h to files that use usermode helpers and
remove linux/kmod.h where it is no longer needed.
Acked-by: Alex Elder <elder@riscstar.com> # for greybus
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
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Linux 7.3-rc4
Requested by Philipp Stanner for
2ab510e63197360945f915dd5631a77c63ac6b27 would be needed as a groundlayer
for further patches that extend the locking in drm_sched
Signed-off-by: Dave Airlie <airlied@redhat.com>
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Both callers of update_prstate(), cpuset_partition_write() and
cpuset_css_killed(), call cpuset_update_sd_hk_unlock() immediately
afterwards. That helper rebuilds sched domains when force_sd_rebuild is
set before releasing the cpuset locks, so the check in update_prstate()
is redundant.
Commit 3bfe47967191 ("cgroup/cpuset: Move
housekeeping_update()/rebuild_sched_domains() together") removed the
same check from cpuset_write_resmask(). Remove the remaining one from
update_prstate().
Signed-off-by: Guopeng Zhang <zhangguopeng@kylinos.cn>
Reviewed-by: Ridong Chen <ridong.chen@linux.dev>
Reviewed-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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Convert open-coded if/else with set_bit/clear_bit and their
non-atomic __set_bit/__clear_bit variants to the assign_bit/__assign_bit
API.
Done with Coccinelle semantic patch:
// set_bit -> clear_bit => assign_bit
@@
expression cond, bit, addr;
@@
-if (cond)
- set_bit(bit, addr);
-else
- clear_bit(bit, addr);
+assign_bit(bit, addr, cond);
// clear_bit -> set_bit => assign_bit
@@
expression cond, bit, addr;
@@
-if (cond)
- clear_bit(bit, addr);
-else
- set_bit(bit, addr);
+assign_bit(bit, addr, !cond);
// __set_bit -> __clear_bit => __assign_bit
@@
expression cond, bit, addr;
@@
-if (cond)
- __set_bit(bit, addr);
-else
- __clear_bit(bit, addr);
+__assign_bit(bit, addr, cond);
// __clear_bit -> __set_bit => __assign_bit
@@
expression cond, bit, addr;
@@
-if (cond)
- __clear_bit(bit, addr);
-else
- __set_bit(bit, addr);
+__assign_bit(bit, addr, !cond);
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Acked-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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Since ad67b74d2469 ("printk: hash addresses printed with %p") %p is hashed
by default, which is also what %pK prints under the default kptr_restrict=0.
Converting the remaining %pK users makes it possible to remove its handling
from vsprintf.
Documentation/process/deprecated.rst asks that no new %p uses be added, but
these pointers are what makes the css_set debug output useful, and debug.c
already prints css pointers with %p. Keep the pointer output and use %p.
Under kptr_restrict=1 and 2 the files now show the same hashed values as any
other %p output: unprivileged readers see hashes instead of zeros, and a
CAP_SYSLOG reader under kptr_restrict=1 no longer gets raw addresses.
Booting with hash_pointers=never is the remaining way to see them.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fix from Tejun Heo:
- The task iterator could pick up a dying task whose refcount had
already dropped to zero and resurrect it, leading to a use-after-free
when reading cgroup.procs. Skip such tasks.
* tag 'cgroup-for-7.3-rc3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup: Avoid iteration of dying tasks with zero refcount
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The commit 260fbcb92bbea ("cgroup: Move dying_tasks cleanup from
cgroup_task_release() to cgroup_task_free()") extended the lifetime of
tasks on the dying_tasks list.
The iterators have provision to go through dying_tasks because of
dying threadgroup leaders or explicit CSS_TASK_ITER_WITH_DEAD, however,
it was expected that such tasks can obtain a new reference (that is
possible before cgroup_task_release()/put_task_struct_rcu_user()).
The tasks after cgroup_task_release() and before cgroup_task_free()
are subject to race when they may or may not have ->usage count > 0.
The race window is between css_task_iter_next() invocations
when css_set_lock is released and we may arrive at a new ->task_pos.
The iterator should not attempt to resurrect tasks whose ->usage count
dropped to zero. (When that happens, __put_task_struct_rcu_cb() is
already imminent and the returned task_struct would could be used
after free.)
As for the fix, we cannot simply check the signal->live count of a task
on the dying list because that won't distinguish regular zombies waiting
to be reaped from RCU remnant tasks that are going to be free'd.
Therefore add an extra check to rule out ->usage==0 tasks from any
iteration.
The repeat: loop in css_task_iter_advance() doesn't consider ->usage
count, so add a new loop to css_task_iter_next() to skip de-used tasks
on the dying_list.
Rough illustration of the possible race
R (reader of cgroup.procs) T (thread) L (group leader)
--------------------------------- -------------------------------- --------------------------------
L exits, signal->live > 0
cgroup_task_dead(L)
css_set_skip_task_iters() // skips only cset->tasks
list_add_tail(&L->cg_list, &cset->dying_tasks)
css_task_iter_next()
take css_set_lock
css_task_iter_advance()
leader && signal->live != 0
=> it->task_pos = &L->cg_list
release css_set_lock
T exits
--signal->live == 0
cgroup_task_dead(T) // css_set_lock
release_task(T)
cgroup_task_release(T)
release_task(L) // zap_leader
cgroup_task_release(L)
put_task_struct_rcu_user(L)
...RCU...
put_task_struct(L)
L->usage = 0
/* L still on dying_tasks */
...RCU...
__put_task_struct(L)
css_task_iter_next() // another iteration
take css_set_lock
it->task_pos = &L->cg_list
get_task_struct(L)
=> addition on 0
drop css_set_lock
cgroup_task_free(L)
css_set_skip_task_iters() // dying skip comes too late
free_task(L)
cgroup_procs_show()
task_pid_vnr(L)
Fixes: 260fbcb92bbea ("cgroup: Move dying_tasks cleanup from cgroup_task_release() to cgroup_task_free()")
Cc: stable@vger.kernel.org # v6.19+
Link: https://lists.debian.org/debian-kernel/2026/08/msg00220.html
Reported-by: Noah Elias Feldt <N.Feldt@mittwald.de>
Reported-by: Salvatore Bonaccorso <carnil@debian.org>
Tested-by: Salvatore Bonaccorso <carnil@debian.org>
Signed-off-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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The kernel-doc comment of dmem_cgroup_try_charge() refers to
dmem_cgroup_evict_valuable, which does not exist. The name is
dmem_cgroup_state_evict_valuable. Say dmem_cgroup_state_evict_valuable.
Fixes: b168ed458dde ("kernel/cgroup: Add "dmem" memory accounting cgroup")
Assisted-by: LLM
Signed-off-by: Karl Mehltretter <kmehltretter@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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cgrp_dead_tasks and cgrp_dead_tasks_iwork are independent per-CPU variables
and are independently accessed via a this_cpu_ptr().
Having a custom struct with those two members makes it possible to have only
one per-CPU accessor and access the second member via an offset. This makes
the code a bit more compact and is a micro-optimization.
Besides that, it allows cgrp_dead_tasks_iwork_fn() to access the list
pointer via the passed iwork pointer. This not only eliminates the
this_cpu_ptr() but also makes it possible to be invoked on a different CPU.
This does not happen as of today but might if I can flush the irq_work items
from another CPU during CPU-hotplug events.
Create struct cgroup_dead with the per-CPU variables as members. Access the
struct with a per-CPU accessor and use container_of() in the irq_work
callback.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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