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git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fixes from Tejun Heo:
- During CPU offline, the active mask drops the CPU before cpuset
updates the effective CPUs, so a task placement in that window could
find no active CPU in the top cpuset and dereference NULL. Restore
the NULL check.
- The cpuset v2-mode test read the subsystem's root pointer, which is
stale during a cgroup filesystem rebind, and the hotplug handler
evaluated it before taking the cpuset mutex. Record the mode in a
flag and test it under the mutex.
* tag 'cgroup-for-7.3-rc6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup/cpuset: Call is_in_v2_mode() after acquiring cpuset_mutex in cpuset_handle_hotplug()
cgroup/cpuset: Handle cpu hotplug race in guarantee_active_cpus()
cgroup/cpuset: Don't access cpuset_cgrp_subsys.root in is_in_v2_mode()
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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>
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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>
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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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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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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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git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fixes from Tejun Heo:
- After cgroup.kill was written to a cgroup, every child cloned into it
with CLONE_INTO_CGROUP was spuriously killed because the fork path
snapshotted the kill counter before resolving the target cgroup
- Releasing an isolated cpuset partition dropped the isolation of CPUs
isolated on the kernel command line
- Selftest and documentation fixes
* tag 'cgroup-for-7.3-rc1-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
selftests/cgroup: test clone3() into a previously killed cgroup
cgroup: fix spurious SIGKILL of CLONE_INTO_CGROUP children
selftests/cgroup: Add test for preserving boot-isolated CPUs
cgroup/cpuset: Preserve boot-isolated CPUs on partition release
selftests/cgroup: Drop invalid boot isolation comparison
docs: cgroup-v2: fix misc.events key format description
selftests/cgroup: Fix cg_run_in_subcgroups ignoring arg parameter
selftests/cgroup: set the test plan after the setup checks
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Since commit b69bb476dee9 ("cgroup: fix race between fork and
cgroup.kill"), the fork path snapshots the kill_seq of the child's
future cgroup into kargs->kill_seq, and cgroup_post_fork() SIGKILLs
the child if that cgroup's kill_seq has changed in the meantime, to
catch forks racing with a cgroup.kill sweep.
For CLONE_INTO_CGROUP, however, the snapshot in cgroup_css_set_fork()
is taken before the target cgroup has been resolved: kargs->cgrp is
always NULL at this point (it is only set at the end of the function).
So the "if (kargs->cgrp)" branch is dead code and the snapshot always
records the kill_seq of the parent's cgroup. cgroup_post_fork() then
compares it with the kill_seq of the target cgroup, so the child gets
SIGKILLed whenever the two cgroups have been killed a different number
of times.
As a result, once cgroup.kill has been written to a cgroup, every
child subsequently cloned into it with clone3(CLONE_INTO_CGROUP) is
killed on the spot, for as long as the cgroup exists: kill_seq is not
exposed to userspace and never resets.
Re-snapshot kill_seq from the target cgroup once it has been resolved,
and drop the dead branch at the early snapshot site.
This does not reopen the race fixed by b69bb476dee9. For
CLONE_INTO_CGROUP, everything from the snapshot to the check in
cgroup_post_fork() runs with cgroup_mutex held, and kill_seq is
only ever incremented under cgroup_mutex.
tj: Updated the comment above kill_seq to reflect the new serialization
rules as suggested by Shakeel Butt.
Fixes: b69bb476dee9 ("cgroup: fix race between fork and cgroup.kill")
Cc: stable@vger.kernel.org
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Assisted-by: LLM
Signed-off-by: Etienne Perot <eperot@google.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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isolated_cpus tracks CPUs isolated with isolcpus= as well as CPUs in
isolated cpuset partitions. When an isolated partition is released,
isolated_cpus_update() removes its whole CPU mask. This also clears CPUs
which were already isolated at boot.
This can be reproduced on a cgroup v2 system booted with
isolcpus=domain,15:
cd /sys/fs/cgroup
echo +cpuset > cgroup.subtree_control
mkdir cpuset-repro
echo 15 > cpuset-repro/cpuset.cpus
echo isolated > cpuset-repro/cpuset.cpus.partition
echo member > cpuset-repro/cpuset.cpus.partition
cat cpuset.cpus.isolated
CPU 15 is absent before the change. It must remain in
cpuset.cpus.isolated after the partition is released.
Update isolated_cpus one CPU at a time and keep CPUs outside the
boot-time domain housekeeping mask isolated.
Fixes: c188f33c864e ("cgroup/cpuset: Account for boot time isolated CPUs")
Signed-off-by: Guopeng Zhang <zhangguopeng@kylinos.cn>
Acked-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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Pull RDMA updates from Jason Gunthorpe:
"About the normal size, still a lot of AI bug fixes and so on, but some
interesting new functionality too:
- Assorted locking, bounds-checking, cleanup, and error-path fixes
across UCMA/CMA, bng_re, bnxt_re, cxgb4, EFA, ERDMA, HFI1, HNS,
ionic, iRDMA, mlx4/mlx5, RXE, SIW, SRP/SRPT, and iSER target.
- netlink report for max # of supported resources
- get_zeroed_page()/etc removal
- Robust udata for ionic
- Allow unique RDMA device names per network namespace
- Completion counters and v2 admit queue support for EFA
- UC QP support for MANA
- Completion timestamps for ionic
- Harden uverbs data validation and resource lifetime handling,
fixing several core use-after-free conditions.
- bnxt_re toggle-page ownership and lifetime bug fixes
- dmabuf SRQ support for mlx5"
* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma: (160 commits)
RDMA/ucma: Allow path records to exactly fit the output buffer
RDMA/uverbs: Guard legacy bundles without method_elm
RDMA/efa: Add support for 128B admin v2 SQ entry
RDMA/efa: Generalize the admin SQ
RDMA/efa: Decouple admin command payload from admin header
RDMA/rxe: Fix OOB in free_rd_atomic_resources()
RDMA/cma: Fix WARNING in res_to_rt
RDMA/cxgb4: Free debugfs on registration failure
RDMA/cxgb4: Cancel reg_work before freeing device on remove
RDMA/ucma: Lock the handler in ucma_set_ib_path()
RDMA/ucma: Lock the handler in ucma_write_cm_event()
RDMA/erdma: restrict the driver to little-endian systems
RDMA/ionic: Embed counter driver data in rdma_counter allocation
RDMA/ionic: Cap eq_count to the eth driver's interrupt vector budget
RDMA/siw: Fix use-after-free in siw_accept()
IB/isert: post the full-feature receive buffers after session registration
IB/isert: delay the final Login Response until the session is registered
RDMA/srp: fix heap information leak on a truncated SRP_CRED_REQ
RDMA/erdma: Hold QP references for AE and CM processing
RDMA/erdma: Hold CQ references when processing EQ events
...
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Pull drm updates from Dave Airlie:
"Highlights:
- dmemcg eviction support is good for low VRAM things like Steam
Machine
- AMD adds gfx6-8 modifier support for older GPUs that enables a
bunch of wayland stuff
- i915/xe has some new hw support but also a lot of display
refactoring
Everything:
perf:
- export perf_allow_ APIs for xe
udmabuf:
- remove default size limit of 64MB
rust:
- i/o rework (signed tag from driver-core tree)
- add registration guard and registration data
- fix unbounded lifetimes in ioctl handler args
- fix a drm_dev_register race
- gem_shmem: add DmaResvGuard helper
- gpuvm: require send/sync for driver data
- implement send/sync for GpuVaAlloc and GpuVmBo
- add SmContext lifetime
- rename dma_handle to dma_address
- change pci_sriov_get_totalvfs return to unsigned int
core:
- create drm_of_get_panel_orientation
- send per-connector hotplug events
- add thunderbolt UBHR tunneling support
connector:
- add color format property
dmem:
- introduce a peak file
- accept one region per limit
- add dmemcg support for eviction
gpusvm:
- reorg code to give drivers more flexibility
atomic:
- add create_state callback and helper
- add documentation on atomic commit lifetime
buddy:
- add per-order free
- add used block scoreboard
- fix UAF
- test buffer clearance on resume
- add phys_addr->block helper
gem:
- drop DRIVER_GEM_GPUVA flag
ttm:
- be more aggressive allocating below protection limit
sched:
- add test suite for concurrent job submissions
hdmi:
- hook the color format property in helpers
mipi-dsi:
- add MIPI_DSI_MODE_DSC_ALL_SLICES_IN_PKT
bridge:
- add atomic create callbacks
- drop atomic reset
- display-connector: don't autoenable HPD IRQ
- trigger initial HPD for DP
- ti-sn65dsi83: remove NO_HFP and NO_HBP mode flags
- analogix_dp: switch to DP link training helpers
dp:
- add support for DSC max delta BPP
edid:
- parse panel type from DisplayID 2.x Display Parameters
sysfb:
- improve panel, stride, framebuffer size validation
panel:
- implement ref counting for struct drm_panel
- himax-hx83121a: add backlight regulator support
- novatek-nt36672a: Inline panel init sequences
- visionox-vtdr6130: enable DSC
- novatek-nt37801: Use mipi_dsi_*_multi() functions
- samsung-s6d16d0: Fix prepare error handling
- support Novatek NT36536 plus DT bindings
- sofef00: fix backlight updates
- osd101t2587: use mipi_dsi_*_multi interface
- panel-edp: adjust timing for AUO displays
- panel-lvds: support Opto Logic SCX1001511GGC49
- panel-simple: support Kyocera tcg070wvlq
- panel-edp: quirks
- AUO B116XAT04.3, CMN N116BCP-EA2, CSW MNB601LS1-8
- BOE NV116WH2-M30, BOE NT116WHM-N21, BOE NV116FH1-M31
- BOE NV116FH1-M30, NV140FHM-N5B, TM156VDXP25
- BOE NE160QDM-NY1, MB116AS01
- new:
- Samsung ATNA40HQ08-0, Anbernic TD4310
- Chipone ICNA35XX, Ilitek ILI9488
- Ilitek ILI7807S, Renesas R63419
- MNE001BS6-2, MNF601BS4-1, Sharp LQ120P1JX51
virtio:
- add support for save/restore virtio_gpu_objects
- abort vq wait on device removal
amdgpu:
- add color format DRM property
- initial compute pipe reset support
- add GFX 6-8 modifier support
- initial DCN 6.0.0 support
- dmemcg eviction support
- improved boundary checking for bios parsing
- RAS updates and rework
- VCN secure submission fixes
- 8K panel fix
- Display KUNIT tests
- parse panel type from DisplayID
- Align IP discovery to pci device lifetime
- SOC15 register macro cleanups
- UVD memory placement fixes
- GFX9 mode2 reset fixes
- drop unnecessary BUG/BUG_ON
- GFX8 soft reset rework
- enable soft reset on GFX8
- PSP/SMU 15.0.9 update
- VI ASPM fix
- userq fixes
- amdgpu_vm_get_task_info_pasid lifetime fix
- DC CACP support
- change system_unbound_wq with system_dfl_wq
- Loosen VFCT bios parsing to deal with pci=realloc
- SI/SMU7 AC/DC switch fix
- VM fence handling fix
- GEM close optimisation
- Apple Studio Display fixes
- DC FRL fixes
amdkfd:
- initial compute pipe reset support
- allow applications to opt out of sigbus on fatal errors
- improve CRIU boundary checks
- MQD handling rework
- move TBA/TMA from system to device memory
- avoid topology-lock in kfd_mmap
- SVM eviction fixes
radeon:
- fix unset CONFIG_ACPI build
i915:
- Novalake (NVL display version 35) timing generator enabling
- NVL DC3CO enabling
- enable UBHR link rates on thunderbolt tunnels
- Reduce Xe3+ PM demand peak bandwidth
- enable pipe DMC error interrupts for display 30+
- add kunit tests for DP link config selection
- refactor and document DP link recovery
- i915/xe driver display probe/remove/suspend/resume/shutdown cleanup
and unification
- i915/xe display runtime PM unified
- Break i915 and xe panic dependency on struct intel_framebuffer
- Streamline Pre/Post-CSC LUT loops
- drop TGL DC3DO support
- CDCLK santization
- fix HDMI scrambling enable
- fix phys bo pread/pwrite with offset
- add missing nospec on parallel submit slot
- fix some NULL derefs
xe:
- drop force_execlist module param
- gate observation streams with perf_allow_cpu
- skip FORCE_WC and vm_bound check for external dma-bufs
- dmemcg eviction support
- remove unused NVL-S GuC
- TLB invalidation improvements
- NVL-S updated PCI-IDs and w/a
- madvise: optimise invalidation path
- fix infinite gt-reset loop in timeout recovery
- update TTM device benefical_order
- wait on external BO kernel fences in exec ioctl
- add/use more KLV helpers
- sriov: disable display in admin only PF mode
- add RAS GPU health indicator
- optimise TTM populate for DONTNEED BO
- drop force_probe for NVL-s
- add debugfs for pcode info
amdxdna:
- disable device buffer export
nova:
- build nova-core/nova-drm from drivers/gpu
- export nova-core rust symbols (workaround)
- GSP boot process consolidation
- Boot GSP with vGPU enabled
- TLV firmware image format support
- Hopper/Blackwell fixes and cleanups
- I/O projection adoption
tyr:
- firmware loading and MCU boot
- add generic slot manager + MMU
- GPU VM support ARM64 LPAE page tables
- add kernel buffer object for internal allocations
- add parser for Mali CSF
- add MCU booting
nouveau:
- race fixes
- check instmem iomapping at first use
- add dmemcg support
- expose NVDEC channels
- add scanline position/head state support for GSP
qxl:
- convert simple encoder to regular
ethosu:
- add perf counter support
etnaviv:
- force flush on power register ops
msm:
- support DSC configuration with slice_per_pkt > 1
mxsfb:
- fix disable sequence
panthor:
- support sparse mappings
rockchip:
- switch away from simple helpers
- support YUV background color
- fix layer config timeout
- add edp support for rk3576
- add batch command submission function
rocket:
- error handling and NULL ptr deref fixes
sun4i:
- switch away from simple helpers
imagination:
- mark BXM-4-64 MC1 as support
host1x:
- support tegra264
tegra:
- add DSI for tegra 20/30
v3d:
- reduce PM runtime autosuspend delay
- scheduler fixes and refactoring
- deprecate v3d 3.3 and 4.1
- validate CPU job query boundaries
hibmc:
- improve plane format handling
- switch to gem shmem
mediatek:
- cec: correct compat for mt7623-8167?
exynos:
- remove simple dependency
- add error handling to encoder paths
- take i2c adapter module reference"
* tag 'drm-next-2026-08-20' of https://gitlab.freedesktop.org/drm/kernel: (2074 commits)
drm/xe/mcr: Take vcs1/vecs1 into account for first media slice
drm/xe: Fix a bug in pc_adjust_freq_bounds()
drm/xe: Fix xe_device_probe() failure
drm/xe/drm_ras: Move has_drm_ras check to drm_ras layer
drm/xe/ras: Fix boot-time ras error processing
drm/amd/display: make DC_RUN_WITH_PREEMPTION_ENABLED misuse a build error
drm/amd/pm: silence uninitialized variable warnings
drm/amdgpu: skip BOs being torn down during GTT recovery
drm/amdgpu: Reject UVD message with invalid number of h265 refs
drm/amdgpu: keep PRT mappings off the vm_bo state lists
drm/amdgpu: fix nbif 6.3.1 l1 low power not functional
drm/amd/display: fix BT.2020 YCbCr output CSC matrices for DCE
drm/amd/display: fix BT.2020 YCbCr limited output CSC matrix
drm/amdgpu: Implement insert_end for VCE 3
drm/amdgpu: Fix UVD min buffer sizes
drm/amdgpu: Fix UVD decode image min size calculation
drm/amdgpu: Fix UVD dpb min size calculation for H264
drm/amdgpu: Reject UVD message with dimensions above 4096
drm/amdgpu: check ASPM on the dGPU host link
drm/radeon: fix autosuspend cleanup during teardown
...
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
- "mm: drop "sub" prefix from various places" (Dev Jain)
page->folio conversion and a naming cleanup
- "mm/kasan: remove redundant initialization for kasan_flag_write_only"
(Igor Putko)
KASAN cleanup work
- "mm/filemap: reduce unnecessary xarray lookups" (Chi Zhiling)
Small speedup in the pagecaache read code
- "mm/percpu: Fix possible NOFS/NOIO reclaim recursion" (Kaitao Cheng)
Improve the vmalloc code - mainly the avoidance of GFP_KERNEL
allocations when the caller asked for GFP_NOFS or GFP_NOIO
- "mm/kmemleak: avoid soft lockup when scanning task stacks" (Breno
Leitao)
Avoid a soft lockup watchdog trigger from the kmemleak scanning code
in extreme situations
- "mm/page_owner: misc cleanups" (Ye Liu)
Cleanups to the page_owner code. For some reason lots of people have
been working on the page_owner code this cycle.
- "mm: convert to walk_page_range_vma() to eliminate find_vma()"
(Kefeng Wang)
Simplify and accelerate the page walking library function
- "mm/migrate: preparatory cleanups for batch copy and offload"
(Shivank Garg)
Cleanups in the migration code
- "mm/page_owner: add per-fd filter infrastructure for print_mode and
NUMA filtering" (Zhen Ni)
Per-fd filtering to page_owner in order to reduce the sometimes vast
amount of output it can produce
- "mm: Refactor bootmem gigantic hugepage allocation" (Muchun Song)
Fixes and preparatory cleanups around bootmem HugeTLB handling,
sparse initialization ordering, and related vmemmap setup
- "mm/zsmalloc: reduce lock contention in zs_free()" (Wenchao Hao)
Reduce lock contention in zs_free(), which dominates the unmap path
under memory pressure on Android (LMK kills) and on x86 servers
running zswap-heavy workloads.
Up to 1.83x improvement in microbenchmarking.
- "move alloc_tag.c file under mm/" (Suren Baghdasaryan)
- "samples/damon: handle damon_{start,stop}() failures" (SJ Park)
Fix improper handling of damon_start(), damon_stop(), and
damon_call() failures across DAMON sample modules to prevent
potential memory leaks, operation disruptions and use-after-free
bugs
- "mm/damon/sysfs: kobject_del() directories that users can
create/remove" (SJ Park)
Fix delayed sysfs directory removal under DEBUG_KOBJECT_RELEASE
causeing creation failures due to duplicate directory names by adding
missing kobject_del() calls before creating new directories
- "mm: cleanup clear_not_present_full_ptes()" (David Hildenbrand)
Clean up the core pte handling code
- "selftests/damon: misc fixes for test bugs" (Kunwu Chan)
Fix several bugs in the DAMON selftests
- "selftests/damon: fix memcg_path staging handling" (Cheng Nie)
Fix a bug in _damon_sysfs.py for damos_filter memcg_path setup, and
add a test case for it in sysfs.py.
- "selftests/damon: test kdamond refresh_ms" (Ruslan Valiyev)
Selftest coverage for DAMON's refresh_ms sysfs feature by updating
the test control module and verifying that scheme stats update
automatically without manual intervention
- "mm/damon: five misc fixups" (Akinobu Mita)
Miscellaneous DAMON fixups.
- "mm/damon/core: detect internal variation above max_nr_regions/2"
(Jiayuan Chen)
Fix DAMON's region splitting behavior when region counts exceed half
the maximum budget by dynamically scaling down the split fraction as
the limit approaches, preventing large regions from staying un-split,
and add corresponding KUnit test coverage
- "mm: preparatory patches for PMD level swap entries" (Usama Arif)
Refactor and clean up PMD softleaf helpers, call sites, and
architecture flags to lay the groundwork for a follow-up series that
introduces PMD page table swap entries
- "mm/damon: update, optimize, and clean up doc, tests, and code" (SJ
Park)
Update DAMON design and ABI documentation, expands unit and selftest
coverage, optimize damon_commit_target_regions(), and clean up
recently added sysfs interface code for better readability
- "mm/vmpressure: reduce CPU, memory and code overhead on cgroup v2"
(Usama Arif)
Optimize vmpressure() by skipping unnecessary work on cgroup v2 for
userspace event notifications and refactor v1-only eventfd handling
into mm/memcontrol-v1.c to reduce memory overhead and code complexity
- "selftests/mm: refactor pkey helpers and fix mmap error handling"
(Hongfu Li)
Refactor pkeys shared tracing and assertion helpers into a common
file, unify protection key selftests to use consistent diagnostic
logging and assertions, and enforce standardized MAP_FAILED return
checks for mmap() calls across the tests
- "mm/damon: optimize out nr_accesses_bp" (SJ Park)
Replace the error-prone, continuously updated nr_accesses_bp field in
damon_region with an on-demand moving sum function, reducing
structure memory overhead and avoiding state corruption bugs
- "Open HugeTLB allocation routine for more generic use" (Ackerley Tng)
Decouple HugeTLB folio allocation from VMA dependencies by
introducing hugetlb_alloc_folio(), enabling subsystems like
guest_memfd to allocate HugeTLB folios without standard VMA
reservations or pseudo-VMAs
- "mm/damon: provide pseudo moving sum probe_hits" (SJ Park)
Integrate DAMON's probe_hits attribute counter into the pseudo moving
sum infrastructure, enabling real-time, online monitoring without
waiting for full aggregation intervals
- "mm: Some cleanups for page allocator APIs" (Brendan Jackman)
Simplify and refactor the page allocator entry points and flags by
unifying allocation paths, adding internal alloc_flags arguments, and
eliminating redundant __ prefixed alloc_pages variants.
- "Fix incorrect access of hugetlb pte entries" (Dev Jain)
Enforce the consistent use of huge_ptep_get() instead of ptep_get()
for HugeTLB entries and fixes an unaligned address issue in arm64's
huge_ptep_get() implementation
- "mm/damon: validate all parameters in the core" (SJ Park)
Consolidate parameter validation into the DAMON core specifically
within damon_start() and damon_commit_ctx() to centralize error
checking, eliminate caller-side redundant checks and to improve
maintenance efficiency
- "tools/mm/page_owner_sort: fix filtering and cleanup issues" (Yichong
Chen)
Rename is_need() to filter_record() for clearer return semantics, fix
per-record allocation memory leaks and bound output copies in
search_pattern() to address an existing buffer issue
- "memcg: bail out reclaim when memcg is dying" (Jiayuan Chen)
Mitigate a system-wide stall which occurs when a cgroup is removed
while one of its memory control files is doing synchronous reclaim
- "mm/memory-failure: add panic option for unrecoverable pages" (Breno
Leitao)
Introduce an opt-in vm.panic_on_unrecoverable_memory_failure sysctl
that immediately panics the kernel on unrecoverable memory errors in
kernel-owned pages to preserve error context and prevent delayed,
silent data corruption
- "mm/damon: refactor damon_{start,stop,commit}() for simple error
handling" (SJ Park)
Refactor the DAMON core API functions to guarantee that all contexts
are fully stopped when damon_start(), damon_stop(), or damon_commit()
fail, eliminating the need for complex and error-prone caller-side
cleanup code
- "Keep tail page private zero at free and folio split" (Zi Yan)
Add checks to ensure tail_page->private is zero when freeing compound
or high-order pages and when promoting tail pages during large folio
splits. By validating these fields at free and split time, it allows
the removal of redundant private field clearing inside
prep_compound_tail()
- "mm: drop redundant lru_add_drain in anon folio reuse paths" (Barry
Song)
Eliminate redundant lru_add_drain() calls in
wp_can_reuse_anon_folio() and do_swap_page() to reduce LRU lock
contention and system overhead
By validating folio refcounts against the LRU cache before draining
and removing unnecessary drains in the swap path, it achieves up to a
30.5% reduction in drain calls during heavy swap workloads
- "mm: clean up folio LRU and swap declarations" (Jianyue Wu)
Reorganize folio LRU and swap code by relocating page-cluster state
to mm/swap_state.c, renaming mm/swap.c to mm/folio.c, and moving
MM-internal reclaim declarations into mm/internal.h.
- "userfaultfd: working set tracking for VM guest memory" (Kiryl
Shutsemau)
Add userfaultfd support for tracking the working set of VM guest
memory, so a VMM can identify hot pages and reclaim cold ones to
tiered or remote storage
- "mm: remove CONFIG_HAVE_BOOTMEM_INFO_NODE (Part 2)" (David
Hildenbrand)
Remove the remaining pieces of CONFIG_HAVE_BOOTMEM_INFO_NODE,
performing some smaller cleanups around freeing of reserved vmemmap
pages on the way.
- "mm/damon: update probe hits for runtime parameter commits" (SJ Park)
Ensure that DAMON's probe_hits attribute counter is properly updated
when monitoring intervals are changed at runtime, matching the
behavior of nr_accesses. To achieve this, it refactors and renames
existing helper functions for shared use, applies the updates to
probe_hits, and handles edge cases in damon_probe_hits_mvsum() to
maintain measurement accuracy.
- "KSM: performance optimizations for rmap_walk_ksm" (xu xin)
Resolve a severe KSM reverse-mapping performance bottleneck where
thousands of split VMAs sharing a single anon_vma cause extended lock
contention.
By adding an interval-filtering check during the rmap walk, it
reduces worst-case anon_vma lock hold times from over 500ms down to
under 2ms, preventing application freezes and latency spikes under
memory pressure.
- "mm: split a couple of headers from internal.h" (Mike Rapoport)
Split declarations related to mm_init, memblock, vmalloc and sparse
into new headers
- "KSM: use linear_page_index in collect_procs_ksm()" (xu xin)
Apply the interval tree optimization from rmap_walk_ksm() to
collect_procs_ksm() to avoid iterating over non-matching VMAs during
KSM memory error handling.
It hoists loop-invariant address initialization and restricts the
anon_vma_interval_tree_foreach walk to a targeted page offset range,
reducing redundant checks and improving lookup efficiency.
- "selftests/mm: avoid false failures in hugetlb and KSM tests" (Sayali
Patil)
Fix issues in the hugetlb and KSM MM selftest categories that can
report failures when the prerequisites for the tests are not
satisfied
- "mm/damon: introduce data attributes only monitoring" (SJ Park)
Introduce attribute-weighted region management in DAMON, allowing
users to prioritize specific data attributes (such as page sizes or
cgroups) over or instead of access monitoring.
By assigning weights to attribute probes, DAMON can completely
disable access tracking and adjust monitoring regions based on
weighted probe-hit counters to optimize monitoring quality for
attribute-focused workloads.
- "mm/hmm: Add mmap lock-drop support for userfaultfd-backed mappings"
(Stanislav Kinsburskii)
Extend hmm_range_fault() to support userfaultfd-backed regions by
allowing the mmap lock to be dropped during fault handling via a new
hmm_range_fault_locked() helper.
By accepting a locked pointer and signaling retry status when lock
release occurs, it enables page fault resolution in userfaultfd
regions while preserving backward compatibility for existing callers.
- "mm: make VMA page offset handling more consistent" (Lorenzo Stoakes)
Clean up and standardize how vma->vm_pgoff is accessed and
manipulated across file-backed and anonymous mappings in the kernel
It introduces dedicated helper functions such as vma_start_pgoff(),
vma_end_pgoff(), vma_set_pgoff() and linear_page_delta() while
renaming rmap interval tree helpers to better reflect their
functionality.
These changes establish a cleaner foundation for future work that
will unify virtual page offset indexing for all anonymous and CoW'd
folios.
- "mm: handle device-private PMDs in walk callbacks" (Usama Arif)
Address kernel panics and state corruption caused by MM walk
callbacks reaching non-present device-private PMD swap entries
created during HMM migrations
It ensures that functions which acquire pmd_trans_huge_lock()
properly recognize device-private PMDs instead of assuming a present
THP or a standard migration entry.
- "mm/rmap: Refactor try_to_unmap_one" (Dev Jain)
Refactor try_to_unmap_one by modularizing Hugetlb,
anonymous-lazyfree, and anonymous-swapbacked logic into dedicated
functions, laying the structural groundwork for batched anonymous
large folio unmapping.
- "Docs/ABI/damon: sysfs ABI document fixes and additions" (Song Hu)
Fix typos and fills in missing entries in the DAMON sysfs ABI
document
- "dax/kmem: atomic whole-device hotplug via sysfs" (Gregory Price)
Introduce an atomic sysfs state attribute and supporting DAX/MM
infrastructure to prevent userland races when offlining and removing
entire memory regions
By adding an unplugged state alongside standard online modes, it
enables whole-device atomic hotplug control while preserving backward
compatibility.
- "mm: convert more vm_flags_t users to vma_flags_t" (Lorenzo Stoakes)
Continue transitioning the kernel from the deprecated vm_flags_t type
to vma_flags_t across core memory management infrastructure.
It replaces legacy type usage in core functions such as do_mmap(),
unmapped area allocation, mm->def_vma_flags, and VMA operations like
mlock, mprotect, and mremap.
- "Two small patches to clean up mm/mm_slot.h" (xu xin)
Refactor mm_slot.h by introducing mm_slot_remove() to unify duplicate
slot deletion sequences in khugepaged and KSM. It also adds code
documentation explaining why mm_slot_lookup and mm_slot_insert must
remain as preprocessor macros rather than static inline functions.
- "mm/damon/core: hide core-private struct fields" (SJ Park)
Clean up DAMON core structures by consistently marking internal-only
fields with private: comment tags to prevent improper direct access
from outer layers.
It enforces encapsulation across core structures including
damon_region, damon_target, and damon_ctx and updates DAMON_SYSFS to
interact through approved access APIs instead of exposing raw struct
members.
- "mm/damon: unurgent fixes for infinite loop, NULL de-ref and races"
(SJ Park)
Address potential infinite loops, NULL dereferences, and race
conditions identified in DAMON
It fixes an infinite loop triggered by extreme user configurations, a
NULL pointer dereference within unit tests and minor monitoring
accuracy degradation caused by subtle runtime races.
- "mm/page_alloc: fixes for free_pages_nolock() on RT/UP" (Brendan
Jackman)
Fix an NMI safety flaw in __free_frozen_pages() where freeing pages
on non-SMP or PREEMPT_RT kernels can bypass can_spin_trylock() checks
via non-PCP or isolated migration paths.
It also resolves potential kernel crashes and privilege escalation
risks triggered when BPF tracing runs in NMI context alongside memory
hotplug or large allocation frees.
- "mm/page_alloc: couple of followups for recent cleanups" (Brendan
Jackman)
Clean up and update page allocator nomenclature, documentation, and
debug assertions.
It aligns internal FPI_ flags with the public "nolock" naming
convention, removes outdated internal implementation details from
high-level page allocator comments, and eliminates obsolete
VM_BUG_ON() assertions in allocation paths.
- "mm/mseal: further cleanups" (Lorenzo Stoakes)
Refactor and simplify the mseal implementation by clarifying API
boundaries and removing unnecessary code complexity.
It replaces generic do_mseal() usage outside the syscall with a
dedicated mseal_mmap_page_zero() helper for MMAP_PAGE_ZERO,
eliminates mm_struct parameters to enforce that sealing applies only
to current->mm, and streamlines overall logic and comments with no
functional changes intended.
- "mm/vmscan: fix swappiness=max and clean up per-node proactive
reclaim" (Ridong Chen)
Resolve reclaim behavior bugs and clean up function parameters across
memory reclaim paths
It fixes swappiness=max in both standard reclaim and MGLRU so
unswappable anonymous memory no longer falls back to evicting page
cache, ensures reclaim_store() returns accurate error codes instead
of collapsing all failures into -EAGAIN, and removes the obsolete
gfp_mask parameter from __node_reclaim().
- "mm: mincore: misc cleanups" (Kefeng Wang)
Clean up and simplifies the mincore code. Most importantly, it
removes the historical special behavior that always reports VM_PFNMAP
pages as non-resident.
- "mm/huge_memory: drop dead split helper variants" (Kiryl Shutsemau)
Two trivial cleanups in the folio split API
- "mm/damon: fix uninitialized DAMOS field and kunit exec expectation
bugs" (SJ Park)
Resolve minor operational and testing bugs in DAMON identified by
Sashiko. It initializes the damos->last_applied field to prevent
occasional efficiency degradation and fixes invalid memory accesses
in DAMON KUnit tests during test failure handling.
- "cleanup for stable_page_flags()" (Jinjiang Tu)
Clean up and refactor stable_page_flags() used by /proc/kpageflags
without altering functionality.
It uses BIT_ULL() to prevent shift-overflow warnings on 64-bit flag
bits, converts folio-specific flag checks to standard folio_test_*()
helpers, and removes redundant CONFIG_PAGE_IDLE_FLAG handling.
- "Batch unmap of uffd-wp file folios" (Dev Jain)
Extend batched folio unmapping support to file folios within
userfaultfd write-protect (uffd-wp) VMAs by adding batching
capabilities to pte_install_uffd_wp_if_needed().
This removes special-case restrictions on uffd-wp VMAs in
try_to_unmap_one(), significantly simplifying the function's control
flow and complexity.
- "mm/early_ioremap: clarify and clean up early_ioremap_reset()"
(Sang-Heon Jeon)
Clarify and clean up the architecture-specific usage of
__late_set_fixmap() and __late_clear_fixmap() after
early_ioremap_reset()
It adds explicit documentation regarding when early_ioremap_reset()
must be called and removes redundant macro definitions and reset
calls in the RISC-V and ARM64 architectures.
- "mm: fix reclaim storms in defrag_mode" (Johannes Weiner)
Address severe performance regressions, swap storms, and spurious
OOMs caused by vm.defrag_mode=1 under high memory pressure in Meta
production
It updates the page allocator slowpath so non-movable allocation
requests actively trigger direct reclaim and direct compaction at
pageblock_order scale, allowing them to claim whole pageblocks rather
than spinning unproductively.
- "zram: lockmap tweaks" (Sebastian Siewior)
Optimize and fix lockdep tracking for zram devices by consolidating
per-entry lockmaps and isolate lock classes across multiple instances
This reduces memory overhead by replacing per-entry lockdep_map
instances with a single map per struct zram, and assigns a dynamic
lock_class_key to each instance to prevent false deadlock reports
when different zram devices are backed by distinct filesystems.
* tag 'mm-stable-2026-08-18-18-39' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (501 commits)
selftests/mm: thuge-gen: fix test_shmget() for PAGE_SIZE check
selftests/mm: unpoison pages in memory-failure teardown
mm/shmem: downgrade final i_blocks check in shmem_evict_inode() to pr_warn()
mm/khugepaged: replace mutex_lock/mutex_unlock usage with guard macro
mm/zsmalloc: fix release order of locks in zs_page_migrate()
Documentation: zram: remove sections numbering
ksm: stop iterating VMAs when ksm_test_exit returns true
mm: fold userfaultfd_rwp() to false without CONFIG_ARCH_HAS_PTE_PROTNONE
mm/migrate: report RCU-tasks quiescent states in migrate_pages_batch()
zram: use a custom key for each zram object
zram: move lockmap to be per-zram instead per table
selftests/mm: fix gup_longterm EINVAL error message
mm: page_alloc: fix non-movable reclaim storm in defrag_mode
mm: page_alloc: move capture_control to the page allocator
mm: compaction: support non-movable compaction for pageblock requests
mm: page_alloc: __GFP_FS lockdep annotation for direct compaction
hugetlb: evaluate subpool free state while locked
mm/damon: remove trailing semicolons after function definitions
mm/damon/ops-common: prevent migration fallback to non-target nodes
mm/damon: update outdated comment about DAMOS filter handling
...
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext
Pull sched_ext updates from Tejun Heo:
"Most of this cycle completes the enqueue-path support for hierarchical
sub-scheduling, which makes sub-scheduler support feature complete: a
root BPF scheduler can now hand a cgroup subtree over to a nested
sub-scheduler together with revocable CPU grants, and the
sub-scheduler owns all scheduling decisions for its tasks on those
CPUs.
Development volume was high and a number of changes plugging holes in
the new support landed late in the cycle. Also included are core
scheduling fixes that were completed too late for the v7.2 release and
are routed through this pull request.
Sub-scheduler CPU delegation:
- Parent schedulers now grant and revoke per-CPU capabilities
(enqueueing, preemption, CPU frequency control) on their children,
enforced on every path a scheduler can reach a CPU through.
Previously only dispatching could be delegated; this lets
sub-schedulers fully schedule their CPUs.
- Rescue execution: a task whose scheduler doesn't have access to the
CPUs the task needs to run on starved until the watchdog ejected
the whole scheduler. The kernel now runs such tasks directly on a
small bandwidth budget, turning a scheduler-killing failure into
bounded degradation.
- Cgroup integration: tasks migrating across a sub-scheduler boundary
weren't re-homed to the new owner, causing wrong-scheduler
scheduling and a use-after-free. Sub-schedulers now take over their
cgroup subtree and receive its cgroup callbacks.
- Arena objects now cross the kernel/BPF boundary as typed pointer
arguments, translated transparently by the BPF tree's new arena
argument support, replacing untyped arguments with manual
translation.
- scx_qmap now demonstrates full hierarchical sub-scheduling.
Other fixes and updates:
- Robustness improvements: the abort path is now NMI-safe, fixing
deadlocks when errors are raised from NMI context and making
hardlockup recovery direct. Reenqueue loops that could monopolize a
CPU ahead of the watchdog now eject the offending scheduler, and
stalls are blamed on the scheduler actually responsible.
- Hardening: BPF-writable arena memory is validated before kernel
use, and task slice and vtime writes got explicit synchronization
rules, closing corruption vectors open to buggy or malicious
schedulers.
- Core scheduling: sched_ext dispatching can drop the rq lock inside
the core-wide pick, which let interleaving selections corrupt each
other's state and hard-hang the machine. The selection now restarts
when the lock was released. The task ordering callback was also
invoked with its arguments swapped, and the default ordering is
updated to work across sub-scheduler boundaries. The fixes are
marked for stable.
- Other fixes headed for stable: a task init leak on fork failure
during enable, tooling compat macros that silently failed to detect
newer kernels, and a crash on reenqueueing against a destroyed
dispatch queue.
- Tooling: scx_pair moves off deprecated callbacks, and the
deprecated scx_bpf_cpu_rq() kfunc is removed"
* tag 'sched_ext-for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext: (144 commits)
sched_ext: Drop the dead SCX_DEQ_CORE_SCHED_EXEC test in dequeue_task_scx()
sched_ext: Make core-sched task ordering hierarchy-aware
sched_ext: Use runnable_at for the default core-sched task ordering
sched_ext: Fix inverted ops.core_sched_before() invocation
sched_ext: Move the config-off sub-cap kfunc stubs into sub.c
sched_ext: Rename balance-era identifiers to dispatch terms
sched_ext: Drop the stale keep_prev fixup in dispatch_pick()
sched_ext: Keep kick_sync waiting on the rq's own CPU
sched_ext: Make SCHED_CLASS_EXT select GENERIC_ALLOCATOR
sched_ext/scx_flatcg: Fix cvtime true-up on slice expiry
sched_ext: Don't BUG_ON a destroyed DSQ in pr |
