affinity of unbound kthreads (node or custom cpumask) against
housekeeping (CPU isolation) constraints and CPU hotplug events.
One crucial missing piece is the handling of cpuset: when an isolated
partition is created, deleted, or its CPUs updated, all the unbound
kthreads in the top cpuset become indifferently affine to _all_ the
non-isolated CPUs, possibly breaking their preferred affinity along
the way.
Solve this with performing the kthreads affinity update from cpuset to
the kthreads consolidated relevant code instead so that preferred
affinities are honoured and applied against the updated cpuset isolated
partitions.
The dispatch of the new isolated cpumasks to timers, workqueues and
kthreads is performed by housekeeping, as per the nice Tejun's
suggestion.
As a welcome side effect, HK_TYPE_DOMAIN then integrates both the set
from boot defined domain isolation (through isolcpus=) and cpuset
isolated partitions. Housekeeping cpumasks are now modifiable with a
specific RCU based synchronization. A big step toward making nohz_full=
also mutable through cpuset in the future.
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Merge tag 'kthread-for-7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks
Pull kthread updates from Frederic Weisbecker:
"The kthread code provides an infrastructure which manages the
preferred affinity of unbound kthreads (node or custom cpumask)
against housekeeping (CPU isolation) constraints and CPU hotplug
events.
One crucial missing piece is the handling of cpuset: when an isolated
partition is created, deleted, or its CPUs updated, all the unbound
kthreads in the top cpuset become indifferently affine to _all_ the
non-isolated CPUs, possibly breaking their preferred affinity along
the way.
Solve this with performing the kthreads affinity update from cpuset to
the kthreads consolidated relevant code instead so that preferred
affinities are honoured and applied against the updated cpuset
isolated partitions.
The dispatch of the new isolated cpumasks to timers, workqueues and
kthreads is performed by housekeeping, as per the nice Tejun's
suggestion.
As a welcome side effect, HK_TYPE_DOMAIN then integrates both the set
from boot defined domain isolation (through isolcpus=) and cpuset
isolated partitions. Housekeeping cpumasks are now modifiable with a
specific RCU based synchronization. A big step toward making
nohz_full= also mutable through cpuset in the future"
* tag 'kthread-for-7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks: (33 commits)
doc: Add housekeeping documentation
kthread: Document kthread_affine_preferred()
kthread: Comment on the purpose and placement of kthread_affine_node() call
kthread: Honour kthreads preferred affinity after cpuset changes
sched/arm64: Move fallback task cpumask to HK_TYPE_DOMAIN
sched: Switch the fallback task allowed cpumask to HK_TYPE_DOMAIN
kthread: Rely on HK_TYPE_DOMAIN for preferred affinity management
kthread: Include kthreadd to the managed affinity list
kthread: Include unbound kthreads in the managed affinity list
kthread: Refine naming of affinity related fields
PCI: Remove superfluous HK_TYPE_WQ check
sched/isolation: Remove HK_TYPE_TICK test from cpu_is_isolated()
cpuset: Remove cpuset_cpu_is_isolated()
timers/migration: Remove superfluous cpuset isolation test
cpuset: Propagate cpuset isolation update to timers through housekeeping
cpuset: Propagate cpuset isolation update to workqueue through housekeeping
PCI: Flush PCI probe workqueue on cpuset isolated partition change
sched/isolation: Flush vmstat workqueues on cpuset isolated partition change
sched/isolation: Flush memcg workqueues on cpuset isolated partition change
cpuset: Update HK_TYPE_DOMAIN cpumask from cpuset
...
When cpuset isolated partitions get updated, unbound kthreads get
indifferently affine to all non isolated CPUs, regardless of their
individual affinity preferences.
For example kswapd is a per-node kthread that prefers to be affine to
the node it refers to. Whenever an isolated partition is created,
updated or deleted, kswapd's node affinity is going to be broken if any
CPU in the related node is not isolated because kswapd will be affine
globally.
Fix this with letting the consolidated kthread managed affinity code do
the affinity update on behalf of cpuset.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Waiman Long <longman@redhat.com>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Marco Crivellari <marco.crivellari@suse.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Waiman Long <longman@redhat.com>
Cc: cgroups@vger.kernel.org
The set of cpuset isolated CPUs is now included in HK_TYPE_DOMAIN
housekeeping cpumask. There is no usecase left interested in just
checking what is isolated by cpuset and not by the isolcpus= kernel
boot parameter.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Waiman Long <longman@redhat.com>
Cc: "Michal Koutný" <mkoutny@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Marco Crivellari <marco.crivellari@suse.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Waiman Long <longman@redhat.com>
Cc: cgroups@vger.kernel.org
Until now, cpuset would propagate isolated partition changes to
timer migration so that unbound timers don't get migrated to isolated
CPUs.
Since housekeeping now centralizes, synchronize and propagates isolation
cpumask changes, perform the work from that subsystem for consolidation
and consistency purposes.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Until now, cpuset would propagate isolated partition changes to
workqueues so that unbound workers get properly reaffined.
Since housekeeping now centralizes, synchronize and propagates isolation
cpumask changes, perform the work from that subsystem for consolidation
and consistency purposes.
For simplification purpose, the target function is adapted to take the
new housekeeping mask instead of the isolated mask.
Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Waiman Long <longman@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: "Michal Koutný" <mkoutny@suse.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Marco Crivellari <marco.crivellari@suse.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Waiman Long <longman@redhat.com>
Cc: cgroups@vger.kernel.org
Until now, HK_TYPE_DOMAIN used to only include boot defined isolated
CPUs passed through isolcpus= boot option. Users interested in also
knowing the runtime defined isolated CPUs through cpuset must use
different APIs: cpuset_cpu_is_isolated(), cpu_is_isolated(), etc...
There are many drawbacks to that approach:
1) Most interested subsystems want to know about all isolated CPUs, not
just those defined on boot time.
2) cpuset_cpu_is_isolated() / cpu_is_isolated() are not synchronized with
concurrent cpuset changes.
3) Further cpuset modifications are not propagated to subsystems
Solve 1) and 2) and centralize all isolated CPUs within the
HK_TYPE_DOMAIN housekeeping cpumask.
Subsystems can rely on RCU to synchronize against concurrent changes.
The propagation mentioned in 3) will be handled in further patches.
[Chen Ridong: Fix cpu_hotplug_lock deadlock and use correct static
branch API]
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Waiman Long <longman@redhat.com>
Reviewed-by: Chen Ridong <chenridong@huawei.com>
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Cc: "Michal Koutný" <mkoutny@suse.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Marco Crivellari <marco.crivellari@suse.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Waiman Long <longman@redhat.com>
Cc: cgroups@vger.kernel.org
cpuset modifies partitions, including isolated, while holding the cpuset
mutex.
This means that holding the cpuset mutex is safe to synchronize against
housekeeping cpumask changes.
Provide a lockdep check to validate that.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: "Michal Koutný" <mkoutny@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Marco Crivellari <marco.crivellari@suse.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Waiman Long <longman@redhat.com>
Cc: cgroups@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
boot_hk_cpus is an ad-hoc copy of HK_TYPE_DOMAIN_BOOT. Remove it and use
the official version.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Phil Auld <pauld@redhat.com>
Reviewed-by: Chen Ridong <chenridong@huawei.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Marco Crivellari <marco.crivellari@suse.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Michal Koutny <mkoutny@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Waiman Long <longman@redhat.com>
Cc: cgroups@vger.kernel.org
An UAF issue was observed:
BUG: KASAN: slab-use-after-free in page_counter_uncharge+0x65/0x150
Write of size 8 at addr ffff888106715440 by task insmod/527
CPU: 4 UID: 0 PID: 527 Comm: insmod 6.19.0-rc7-next-20260129+ #11
Tainted: [O]=OOT_MODULE
Call Trace:
<TASK>
dump_stack_lvl+0x82/0xd0
kasan_report+0xca/0x100
kasan_check_range+0x39/0x1c0
page_counter_uncharge+0x65/0x150
dmem_cgroup_uncharge+0x1f/0x260
Allocated by task 527:
Freed by task 0:
The buggy address belongs to the object at ffff888106715400
which belongs to the cache kmalloc-512 of size 512
The buggy address is located 64 bytes inside of
freed 512-byte region [ffff888106715400, ffff888106715600)
The buggy address belongs to the physical page:
Memory state around the buggy address:
ffff888106715300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888106715380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888106715400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888106715480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888106715500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
The issue occurs because a pool can still be held by a caller after its
associated memory region is unregistered. The current implementation frees
the pool even if users still hold references to it (e.g., before uncharge
operations complete).
This patch adds a reference counter to each pool, ensuring that a pool is
only freed when its reference count drops to zero.
Fixes: b168ed458d ("kernel/cgroup: Add "dmem" memory accounting cgroup")
Cc: stable@vger.kernel.org # v6.14+
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
A warnning was detected:
WARNING: suspicious RCU usage
6.19.0-rc7-next-20260129+ #1101 Tainted: G O
kernel/cgroup/dmem.c:456 suspicious rcu_dereference_check() usage!
other info that might help us debug this:
rcu_scheduler_active = 2, debug_locks = 1
1 lock held by insmod/532:
#0: ffffffff85e78b38 (dmemcg_lock){+.+.}-dmem_cgroup_unregister_region+
stack backtrace:
CPU: 2 UID: 0 PID: 532 Comm: insmod Tainted: 6.19.0-rc7-next-
Tainted: [O]=OOT_MODULE
Call Trace:
<TASK>
dump_stack_lvl+0xb0/0xd0
lockdep_rcu_suspicious+0x151/0x1c0
dmem_cgroup_unregister_region+0x1e2/0x380
? __pfx_dmem_test_init+0x10/0x10 [dmem_uaf]
dmem_test_init+0x65/0xff0 [dmem_uaf]
do_one_initcall+0xbb/0x3a0
The macro list_for_each_rcu() must be used within an RCU read-side critical
section (between rcu_read_lock() and rcu_read_unlock()). Using it outside
that context, as seen in dmem_cgroup_unregister_region(), triggers the
lockdep warning because the RCU protection is not guaranteed.
Replace list_for_each_rcu() with list_for_each_entry_safe(), which is
appropriate for traversal under spinlock protection where nodes may be
deleted.
Fixes: b168ed458d ("kernel/cgroup: Add "dmem" memory accounting cgroup")
Cc: stable@vger.kernel.org # v6.14+
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Add an appropriate SPDX-License-Identifier line to the file,
and remove the GNU boilerplate text.
Signed-off-by: Tim Bird <tim.bird@sony.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Add GPL-2.0 SPDX license id lines to a few old
files, replacing the reference to the COPYING file.
The COPYING file at the time of creation of these files
(2007 and 2005) was GPL-v2.0, with an additional clause
indicating that only v2 applied.
Signed-off-by: Tim Bird <tim.bird@sony.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
The cgrp_ancestor_storage has two drawbacks:
- it's not guaranteed that the member immediately follows struct cgrp in
cgroup_root (root cgroup's ancestors[0] might thus point to a padding
and not in cgrp_ancestor_storage proper),
- this idiom raises warnings with -Wflex-array-member-not-at-end.
Instead of relying on the auxiliary member in cgroup_root, define the
0-th level ancestor inside struct cgroup (needed for static allocation
of cgrp_dfl_root), deeper cgroups would allocate flexible
_low_ancestors[]. Unionized alias through ancestors[] will
transparently join the two ranges.
The above change would still leave the flexible array at the end of
struct cgroup inside cgroup_root, so move cgrp also towards the end of
cgroup_root to resolve the -Wflex-array-member-not-at-end.
Link: https://lore.kernel.org/r/5fb74444-2fbb-476e-b1bf-3f3e279d0ced@embeddedor.com/
Reported-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Closes: https://lore.kernel.org/r/b3eb050d-9451-4b60-b06c-ace7dab57497@embeddedor.com/
Cc: David Laight <david.laight.linux@gmail.com>
Acked-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
A warning was triggered as follows:
WARNING: kernel/cgroup/cpuset.c:1651 at remote_partition_disable+0xf7/0x110
RIP: 0010:remote_partition_disable+0xf7/0x110
RSP: 0018:ffffc90001947d88 EFLAGS: 00000206
RAX: 0000000000007fff RBX: ffff888103b6e000 RCX: 0000000000006f40
RDX: 0000000000006f00 RSI: ffffc90001947da8 RDI: ffff888103b6e000
RBP: ffff888103b6e000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: ffff88810b2e2728 R12: ffffc90001947da8
R13: 0000000000000000 R14: ffffc90001947da8 R15: ffff8881081f1c00
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f55c8bbe0b2 CR3: 000000010b14c000 CR4: 00000000000006f0
Call Trace:
<TASK>
update_prstate+0x2d3/0x580
cpuset_partition_write+0x94/0xf0
kernfs_fop_write_iter+0x147/0x200
vfs_write+0x35d/0x500
ksys_write+0x66/0xe0
do_syscall_64+0x6b/0x390
entry_SYSCALL_64_after_hwframe+0x4b/0x53
RIP: 0033:0x7f55c8cd4887
Reproduction steps (on a 16-CPU machine):
# cd /sys/fs/cgroup/
# mkdir A1
# echo +cpuset > A1/cgroup.subtree_control
# echo "0-14" > A1/cpuset.cpus.exclusive
# mkdir A1/A2
# echo "0-14" > A1/A2/cpuset.cpus.exclusive
# echo "root" > A1/A2/cpuset.cpus.partition
# echo 0 > /sys/devices/system/cpu/cpu15/online
# echo member > A1/A2/cpuset.cpus.partition
When CPU 15 is offlined, subpartitions_cpus gets cleared because no CPUs
remain available for the top_cpuset, forcing partitions to share CPUs with
the top_cpuset. In this scenario, disabling the remote partition triggers
a warning stating that effective_xcpus is not a subset of
subpartitions_cpus. Partitions should be invalidated in this case to
inform users that the partition is now invalid(cpus are shared with
top_cpuset).
To fix this issue:
1. Only emit the warning only if subpartitions_cpus is not empty and the
effective_xcpus is not a subset of subpartitions_cpus.
2. During the CPU hotplug process, invalidate partitions if
subpartitions_cpus is empty.
Fixes: f62a5d3936 ("cgroup/cpuset: Remove remote_partition_check() & make update_cpumasks_hier() handle remote partition")
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
On x86-64, this_cpu_cmpxchg() uses CMPXCHG without LOCK prefix which
means it is only safe for the local CPU and not for multiple CPUs.
Recently the commit 36df6e3dbd ("cgroup: make css_rstat_updated nmi
safe") make css_rstat_updated lockless and uses lockless list to allow
reentrancy. Since css_rstat_updated can invoked from process context,
IRQ and NMI, it uses this_cpu_cmpxchg() to select the winner which will
inset the lockless lnode into the global per-cpu lockless list.
However the commit missed one case where lockless node of a cgroup can
be accessed and modified by another CPU doing the flushing. Basically
llist_del_first_init() in css_process_update_tree().
On a cursory look, it can be questioned how css_process_update_tree()
can see a lockless node in global lockless list where the updater is at
this_cpu_cmpxchg() and before llist_add() call in css_rstat_updated().
This can indeed happen in the presence of IRQs/NMI.
Consider this scenario: Updater for cgroup stat C on CPU A in process
context is after llist_on_list() check and before this_cpu_cmpxchg() in
css_rstat_updated() where it get interrupted by IRQ/NMI. In the IRQ/NMI
context, a new updater calls css_rstat_updated() for same cgroup C and
successfully inserts rstatc_pcpu->lnode.
Now concurrently CPU B is running the flusher and it calls
llist_del_first_init() for CPU A and got rstatc_pcpu->lnode of cgroup C
which was added by the IRQ/NMI updater.
Now imagine CPU B calling init_llist_node() on cgroup C's
rstatc_pcpu->lnode of CPU A and on CPU A, the process context updater
calling this_cpu_cmpxchg(rstatc_pcpu->lnode) concurrently.
The CMPXCNG without LOCK on CPU A is not safe and thus we need LOCK
prefix.
In Meta's fleet running the kernel with the commit 36df6e3dbd, we are
observing on some machines the memcg stats are getting skewed by more
than the actual memory on the system. On close inspection, we noticed
that lockless node for a workload for specific CPU was in the bad state
and thus all the updates on that CPU for that cgroup was being lost.
To confirm if this skew was indeed due to this CMPXCHG without LOCK in
css_rstat_updated(), we created a repro (using AI) at [1] which shows
that CMPXCHG without LOCK creates almost the same lnode corruption as
seem in Meta's fleet and with LOCK CMPXCHG the issue does not
reproduces.
Link: http://lore.kernel.org/efiagdwmzfwpdzps74fvcwq3n4cs36q33ij7eebcpssactv3zu@se4hqiwxcfxq [1]
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: stable@vger.kernel.org # v6.17+
Fixes: 36df6e3dbd ("cgroup: make css_rstat_updated nmi safe")
Signed-off-by: Tejun Heo <tj@kernel.org>
- The 10 patch series "__vmalloc()/kvmalloc() and no-block support" from
Uladzislau Rezki reworks the vmalloc() code to support non-blocking
allocations (GFP_ATOIC, GFP_NOWAIT).
- The 2 patch series "ksm: fix exec/fork inheritance" from xu xin fixes
a rare case where the KSM MMF_VM_MERGE_ANY prctl state is not inherited
across fork/exec.
- The 4 patch series "mm/zswap: misc cleanup of code and documentations"
from SeongJae Park does some light maintenance work on the zswap code.
- The 5 patch series "mm/page_owner: add debugfs files 'show_handles'
and 'show_stacks_handles'" from Mauricio Faria de Oliveira enhances the
/sys/kernel/debug/page_owner debug feature. It adds unique identifiers
to differentiate the various stack traces so that userspace monitoring
tools can better match stack traces over time.
- The 2 patch series "mm/page_alloc: pcp->batch cleanups" from Joshua
Hahn makes some minor alterations to the page allocator's per-cpu-pages
feature.
- The 2 patch series "Improve UFFDIO_MOVE scalability by removing
anon_vma lock" from Lokesh Gidra addresses a scalability issue in
userfaultfd's UFFDIO_MOVE operation.
- The 2 patch series "kasan: cleanups for kasan_enabled() checks" from
Sabyrzhan Tasbolatov performs some cleanup in the KASAN code.
- The 2 patch series "drivers/base/node: fold node register and
unregister functions" from Donet Tom cleans up the NUMA node handling
code a little.
- The 4 patch series "mm: some optimizations for prot numa" from Kefeng
Wang provides some cleanups and small optimizations to the NUMA
allocation hinting code.
- The 5 patch series "mm/page_alloc: Batch callers of
free_pcppages_bulk" from Joshua Hahn addresses long lock hold times at
boot on large machines. These were causing (harmless) softlockup
warnings.
- The 2 patch series "optimize the logic for handling dirty file folios
during reclaim" from Baolin Wang removes some now-unnecessary work from
page reclaim.
- The 10 patch series "mm/damon: allow DAMOS auto-tuned for per-memcg
per-node memory usage" from SeongJae Park enhances the DAMOS auto-tuning
feature.
- The 2 patch series "mm/damon: fixes for address alignment issues in
DAMON_LRU_SORT and DAMON_RECLAIM" from Quanmin Yan fixes DAMON_LRU_SORT
and DAMON_RECLAIM with certain userspace configuration.
- The 15 patch series "expand mmap_prepare functionality, port more
users" from Lorenzo Stoakes enhances the new(ish)
file_operations.mmap_prepare() method and ports additional callsites
from the old ->mmap() over to ->mmap_prepare().
- The 8 patch series "Fix stale IOTLB entries for kernel address space"
from Lu Baolu fixes a bug (and possible security issue on non-x86) in
the IOMMU code. In some situations the IOMMU could be left hanging onto
a stale kernel pagetable entry.
- The 4 patch series "mm/huge_memory: cleanup __split_unmapped_folio()"
from Wei Yang cleans up and optimizes the folio splitting code.
- The 5 patch series "mm, swap: misc cleanup and bugfix" from Kairui
Song implements some cleanups and a minor fix in the swap discard code.
- The 8 patch series "mm/damon: misc documentation fixups" from SeongJae
Park does as advertised.
- The 9 patch series "mm/damon: support pin-point targets removal" from
SeongJae Park permits userspace to remove a specific monitoring target
in the middle of the current targets list.
- The 2 patch series "mm: MISC follow-up patches for linux/pgalloc.h"
from Harry Yoo implements a couple of cleanups related to mm header file
inclusion.
- The 2 patch series "mm/swapfile.c: select swap devices of default
priority round robin" from Baoquan He improves the selection of swap
devices for NUMA machines.
- The 3 patch series "mm: Convert memory block states (MEM_*) macros to
enums" from Israel Batista changes the memory block labels from macros
to enums so they will appear in kernel debug info.
- The 3 patch series "ksm: perform a range-walk to jump over holes in
break_ksm" from Pedro Demarchi Gomes addresses an inefficiency when KSM
unmerges an address range.
- The 22 patch series "mm/damon/tests: fix memory bugs in kunit tests"
from SeongJae Park fixes leaks and unhandled malloc() failures in DAMON
userspace unit tests.
- The 2 patch series "some cleanups for pageout()" from Baolin Wang
cleans up a couple of minor things in the page scanner's
writeback-for-eviction code.
- The 2 patch series "mm/hugetlb: refactor sysfs/sysctl interfaces" from
Hui Zhu moves hugetlb's sysfs/sysctl handling code into a new file.
- The 9 patch series "introduce VM_MAYBE_GUARD and make it sticky" from
Lorenzo Stoakes makes the VMA guard regions available in /proc/pid/smaps
and improves the mergeability of guarded VMAs.
- The 2 patch series "mm: perform guard region install/remove under VMA
lock" from Lorenzo Stoakes reduces mmap lock contention for callers
performing VMA guard region operations.
- The 2 patch series "vma_start_write_killable" from Matthew Wilcox
starts work in permitting applications to be killed when they are
waiting on a read_lock on the VMA lock.
- The 11 patch series "mm/damon/tests: add more tests for online
parameters commit" from SeongJae Park adds additional userspace testing
of DAMON's "commit" feature.
- The 9 patch series "mm/damon: misc cleanups" from SeongJae Park does
that.
- The 2 patch series "make VM_SOFTDIRTY a sticky VMA flag" from Lorenzo
Stoakes addresses the possible loss of a VMA's VM_SOFTDIRTY flag when
that VMA is merged with another.
- The 16 patch series "mm: support device-private THP" from Balbir Singh
introduces support for Transparent Huge Page (THP) migration in zone
device-private memory.
- The 3 patch series "Optimize folio split in memory failure" from Zi
Yan optimizes folio split operations in the memory failure code.
- The 2 patch series "mm/huge_memory: Define split_type and consolidate
split support checks" from Wei Yang provides some more cleanups in the
folio splitting code.
- The 16 patch series "mm: remove is_swap_[pte, pmd]() + non-swap
entries, introduce leaf entries" from Lorenzo Stoakes cleans up our
handling of pagetable leaf entries by introducing the concept of
'software leaf entries', of type softleaf_t.
- The 4 patch series "reparent the THP split queue" from Muchun Song
reparents the THP split queue to its parent memcg. This is in
preparation for addressing the long-standing "dying memcg" problem,
wherein dead memcg's linger for too long, consuming memory resources.
- The 3 patch series "unify PMD scan results and remove redundant
cleanup" from Wei Yang does a little cleanup in the hugepage collapse
code.
- The 6 patch series "zram: introduce writeback bio batching" from
Sergey Senozhatsky improves zram writeback efficiency by introducing
batched bio writeback support.
- The 4 patch series "memcg: cleanup the memcg stats interfaces" from
Shakeel Butt cleans up our handling of the interrupt safety of some
memcg stats.
- The 4 patch series "make vmalloc gfp flags usage more apparent" from
Vishal Moola cleans up vmalloc's handling of incoming GFP flags.
- The 6 patch series "mm: Add soft-dirty and uffd-wp support for RISC-V"
from Chunyan Zhang teches soft dirty and userfaultfd write protect
tracking to use RISC-V's Svrsw60t59b extension.
- The 5 patch series "mm: swap: small fixes and comment cleanups" from
Youngjun Park fixes a small bug and cleans up some of the swap code.
- The 4 patch series "initial work on making VMA flags a bitmap" from
Lorenzo Stoakes starts work on converting the vma struct's flags to a
bitmap, so we stop running out of them, especially on 32-bit.
- The 2 patch series "mm/swapfile: fix and cleanup swap list iterations"
from Youngjun Park addresses a possible bug in the swap discard code and
cleans things up a little.
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Merge tag 'mm-stable-2025-12-03-21-26' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
"__vmalloc()/kvmalloc() and no-block support" (Uladzislau Rezki)
Rework the vmalloc() code to support non-blocking allocations
(GFP_ATOIC, GFP_NOWAIT)
"ksm: fix exec/fork inheritance" (xu xin)
Fix a rare case where the KSM MMF_VM_MERGE_ANY prctl state is not
inherited across fork/exec
"mm/zswap: misc cleanup of code and documentations" (SeongJae Park)
Some light maintenance work on the zswap code
"mm/page_owner: add debugfs files 'show_handles' and 'show_stacks_handles'" (Mauricio Faria de Oliveira)
Enhance the /sys/kernel/debug/page_owner debug feature by adding
unique identifiers to differentiate the various stack traces so
that userspace monitoring tools can better match stack traces over
time
"mm/page_alloc: pcp->batch cleanups" (Joshua Hahn)
Minor alterations to the page allocator's per-cpu-pages feature
"Improve UFFDIO_MOVE scalability by removing anon_vma lock" (Lokesh Gidra)
Address a scalability issue in userfaultfd's UFFDIO_MOVE operation
"kasan: cleanups for kasan_enabled() checks" (Sabyrzhan Tasbolatov)
"drivers/base/node: fold node register and unregister functions" (Donet Tom)
Clean up the NUMA node handling code a little
"mm: some optimizations for prot numa" (Kefeng Wang)
Cleanups and small optimizations to the NUMA allocation hinting
code
"mm/page_alloc: Batch callers of free_pcppages_bulk" (Joshua Hahn)
Address long lock hold times at boot on large machines. These were
causing (harmless) softlockup warnings
"optimize the logic for handling dirty file folios during reclaim" (Baolin Wang)
Remove some now-unnecessary work from page reclaim
"mm/damon: allow DAMOS auto-tuned for per-memcg per-node memory usage" (SeongJae Park)
Enhance the DAMOS auto-tuning feature
"mm/damon: fixes for address alignment issues in DAMON_LRU_SORT and DAMON_RECLAIM" (Quanmin Yan)
Fix DAMON_LRU_SORT and DAMON_RECLAIM with certain userspace
configuration
"expand mmap_prepare functionality, port more users" (Lorenzo Stoakes)
Enhance the new(ish) file_operations.mmap_prepare() method and port
additional callsites from the old ->mmap() over to ->mmap_prepare()
"Fix stale IOTLB entries for kernel address space" (Lu Baolu)
Fix a bug (and possible security issue on non-x86) in the IOMMU
code. In some situations the IOMMU could be left hanging onto a
stale kernel pagetable entry
"mm/huge_memory: cleanup __split_unmapped_folio()" (Wei Yang)
Clean up and optimize the folio splitting code
"mm, swap: misc cleanup and bugfix" (Kairui Song)
Some cleanups and a minor fix in the swap discard code
"mm/damon: misc documentation fixups" (SeongJae Park)
"mm/damon: support pin-point targets removal" (SeongJae Park)
Permit userspace to remove a specific monitoring target in the
middle of the current targets list
"mm: MISC follow-up patches for linux/pgalloc.h" (Harry Yoo)
A couple of cleanups related to mm header file inclusion
"mm/swapfile.c: select swap devices of default priority round robin" (Baoquan He)
improve the selection of swap devices for NUMA machines
"mm: Convert memory block states (MEM_*) macros to enums" (Israel Batista)
Change the memory block labels from macros to enums so they will
appear in kernel debug info
"ksm: perform a range-walk to jump over holes in break_ksm" (Pedro Demarchi Gomes)
Address an inefficiency when KSM unmerges an address range
"mm/damon/tests: fix memory bugs in kunit tests" (SeongJae Park)
Fix leaks and unhandled malloc() failures in DAMON userspace unit
tests
"some cleanups for pageout()" (Baolin Wang)
Clean up a couple of minor things in the page scanner's
writeback-for-eviction code
"mm/hugetlb: refactor sysfs/sysctl interfaces" (Hui Zhu)
Move hugetlb's sysfs/sysctl handling code into a new file
"introduce VM_MAYBE_GUARD and make it sticky" (Lorenzo Stoakes)
Make the VMA guard regions available in /proc/pid/smaps and
improves the mergeability of guarded VMAs
"mm: perform guard region install/remove under VMA lock" (Lorenzo Stoakes)
Reduce mmap lock contention for callers performing VMA guard region
operations
"vma_start_write_killable" (Matthew Wilcox)
Start work on permitting applications to be killed when they are
waiting on a read_lock on the VMA lock
"mm/damon/tests: add more tests for online parameters commit" (SeongJae Park)
Add additional userspace testing of DAMON's "commit" feature
"mm/damon: misc cleanups" (SeongJae Park)
"make VM_SOFTDIRTY a sticky VMA flag" (Lorenzo Stoakes)
Address the possible loss of a VMA's VM_SOFTDIRTY flag when that
VMA is merged with another
"mm: support device-private THP" (Balbir Singh)
Introduce support for Transparent Huge Page (THP) migration in zone
device-private memory
"Optimize folio split in memory failure" (Zi Yan)
"mm/huge_memory: Define split_type and consolidate split support checks" (Wei Yang)
Some more cleanups in the folio splitting code
"mm: remove is_swap_[pte, pmd]() + non-swap entries, introduce leaf entries" (Lorenzo Stoakes)
Clean up our handling of pagetable leaf entries by introducing the
concept of 'software leaf entries', of type softleaf_t
"reparent the THP split queue" (Muchun Song)
Reparent the THP split queue to its parent memcg. This is in
preparation for addressing the long-standing "dying memcg" problem,
wherein dead memcg's linger for too long, consuming memory
resources
"unify PMD scan results and remove redundant cleanup" (Wei Yang)
A little cleanup in the hugepage collapse code
"zram: introduce writeback bio batching" (Sergey Senozhatsky)
Improve zram writeback efficiency by introducing batched bio
writeback support
"memcg: cleanup the memcg stats interfaces" (Shakeel Butt)
Clean up our handling of the interrupt safety of some memcg stats
"make vmalloc gfp flags usage more apparent" (Vishal Moola)
Clean up vmalloc's handling of incoming GFP flags
"mm: Add soft-dirty and uffd-wp support for RISC-V" (Chunyan Zhang)
Teach soft dirty and userfaultfd write protect tracking to use
RISC-V's Svrsw60t59b extension
"mm: swap: small fixes and comment cleanups" (Youngjun Park)
Fix a small bug and clean up some of the swap code
"initial work on making VMA flags a bitmap" (Lorenzo Stoakes)
Start work on converting the vma struct's flags to a bitmap, so we
stop running out of them, especially on 32-bit
"mm/swapfile: fix and cleanup swap list iterations" (Youngjun Park)
Address a possible bug in the swap discard code and clean things
up a little
[ This merge also reverts commit ebb9aeb980 ("vfio/nvgrace-gpu:
register device memory for poison handling") because it looks
broken to me, I've asked for clarification - Linus ]
* tag 'mm-stable-2025-12-03-21-26' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (321 commits)
mm: fix vma_start_write_killable() signal handling
mm/swapfile: use plist_for_each_entry in __folio_throttle_swaprate
mm/swapfile: fix list iteration when next node is removed during discard
fs/proc/task_mmu.c: fix make_uffd_wp_huge_pte() huge pte handling
mm/kfence: add reboot notifier to disable KFENCE on shutdown
memcg: remove inc/dec_lruvec_kmem_state helpers
selftests/mm/uffd: initialize char variable to Null
mm: fix DEBUG_RODATA_TEST indentation in Kconfig
mm: introduce VMA flags bitmap type
tools/testing/vma: eliminate dependency on vma->__vm_flags
mm: simplify and rename mm flags function for clarity
mm: declare VMA flags by bit
zram: fix a spelling mistake
mm/page_alloc: optimize lowmem_reserve max lookup using its semantic monotonicity
mm/vmscan: skip increasing kswapd_failures when reclaim was boosted
pagemap: update BUDDY flag documentation
mm: swap: remove scan_swap_map_slots() references from comments
mm: swap: change swap_alloc_slow() to void
mm, swap: remove redundant comment for read_swap_cache_async
mm, swap: use SWP_SOLIDSTATE to determine if swap is rotational
...
- Defer task cgroup unlink until after the dying task's final context switch
so that controllers see the cgroup properly populated until the task is
truly gone.
- cpuset cleanups and simplifications. Enforce that domain isolated CPUs
stay in root or isolated partitions and fail if isolated+nohz_full would
leave no housekeeping CPU. Fix sched/deadline root domain handling during
CPU hot-unplug and race for tasks in attaching cpusets.
- Misc fixes including memory reclaim protection documentation and selftest
KTAP conformance.
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Merge tag 'cgroup-for-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup updates from Tejun Heo:
- Defer task cgroup unlink until after the dying task's final context
switch so that controllers see the cgroup properly populated until
the task is truly gone
- cpuset cleanups and simplifications.
Enforce that domain isolated CPUs stay in root or isolated partitions
and fail if isolated+nohz_full would leave no housekeeping CPU. Fix
sched/deadline root domain handling during CPU hot-unplug and race
for tasks in attaching cpusets
- Misc fixes including memory reclaim protection documentation and
selftest KTAP conformance
* tag 'cgroup-for-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (21 commits)
cpuset: Treat cpusets in attaching as populated
sched/deadline: Walk up cpuset hierarchy to decide root domain when hot-unplug
cgroup/cpuset: Introduce cpuset_cpus_allowed_locked()
docs: cgroup: No special handling of unpopulated memcgs
docs: cgroup: Note about sibling relative reclaim protection
docs: cgroup: Explain reclaim protection target
selftests/cgroup: conform test to KTAP format output
cpuset: remove need_rebuild_sched_domains
cpuset: remove global remote_children list
cpuset: simplify node setting on error
cgroup: include missing header for struct irq_work
cgroup: Fix sleeping from invalid context warning on PREEMPT_RT
cgroup/cpuset: Globally track isolated_cpus update
cgroup/cpuset: Ensure domain isolated CPUs stay in root or isolated partition
cgroup/cpuset: Move up prstate_housekeeping_conflict() helper
cgroup/cpuset: Fail if isolated and nohz_full don't leave any housekeeping
cgroup/cpuset: Rename update_unbound_workqueue_cpumask() to update_isolation_cpumasks()
cgroup: Defer task cgroup unlink until after the task is done switching out
cgroup: Move dying_tasks cleanup from cgroup_task_release() to cgroup_task_free()
cgroup: Rename cgroup lifecycle hooks to cgroup_task_*()
...
- Introduce and document a QoS limit on CPU exit latency during wakeup
from suspend-to-idle (Ulf Hansson)
- Add support for building libcpupower statically (Zuo An)
- Add support for sending netlink notifications to user space on energy
model updates (Changwoo Mini, Peng Fan)
- Minor improvements to the Rust OPP interface (Tamir Duberstein)
- Fixes to scope-based pointers in the OPP library (Viresh Kumar)
- Use residency threshold in polling state override decisions in the
menu cpuidle governor (Aboorva Devarajan)
- Add sanity check for exit latency and target residency in the cpufreq
core (Rafael Wysocki)
- Use this_cpu_ptr() where possible in the teo governor (Christian
Loehle)
- Rework the handling of tick wakeups in the teo cpuidle governor to
increase the likelihood of stopping the scheduler tick in the cases
when tick wakeups can be counted as non-timer ones (Rafael Wysocki)
- Fix a reverse condition in the teo cpuidle governor and drop a
misguided target residency check from it (Rafael Wysocki)
- Clean up multiple minor defects in the teo cpuidle governor (Rafael
Wysocki)
- Update header inclusion to make it follow the Include What You Use
principle (Andy Shevchenko)
- Enable MSR-based RAPL PMU support in the intel_rapl power capping
driver and arrange for using it on the Panther Lake and Wildcat Lake
processors (Kuppuswamy Sathyanarayanan)
- Add support for Nova Lake and Wildcat Lake processors to the
intel_rapl power capping driver (Kaushlendra Kumar, Srinivas
Pandruvada)
- Add OPP and bandwidth support for Tegra186 (Aaron Kling)
- Optimizations for parameter array handling in the amd-pstate cpufreq
driver (Mario Limonciello)
- Fix for mode changes with offline CPUs in the amd-pstate cpufreq
driver (Gautham Shenoy)
- Preserve freq_table_sorted across suspend/hibernate in the cpufreq
core (Zihuan Zhang)
- Adjust energy model rules for Intel hybrid platforms in the
intel_pstate cpufreq driver and improve printing of debug messages
in it (Rafael Wysocki)
- Replace deprecated strcpy() in cpufreq_unregister_governor()
(Thorsten Blum)
- Fix duplicate hyperlink target errors in the intel_pstate cpufreq
driver documentation and use :ref: directive for internal linking in
it (Swaraj Gaikwad, Bagas Sanjaya)
- Add Diamond Rapids OOB mode support to the intel_pstate cpufreq
driver (Kuppuswamy Sathyanarayanan)
- Use mutex guard for driver locking in the intel_pstate driver and
eliminate some code duplication from it (Rafael Wysocki)
- Replace udelay() with usleep_range() in ACPI cpufreq (Kaushlendra
Kumar)
- Minor improvements to various cpufreq drivers (Christian Marangi, Hal
Feng, Jie Zhan, Marco Crivellari, Miaoqian Lin, and Shuhao Fu)
- Replace snprintf() with scnprintf() in show_trace_dev_match()
(Kaushlendra Kumar)
- Fix memory allocation error handling in pm_vt_switch_required()
(Malaya Kumar Rout)
- Introduce CALL_PM_OP() macro and use it to simplify code in
generic PM operations (Kaushlendra Kumar)
- Add module param to backtrace all CPUs in the device power management
watchdog (Sergey Senozhatsky)
- Rework message printing in swsusp_save() (Rafael Wysocki)
- Make it possible to change the number of hibernation compression
threads (Xueqin Luo)
- Clarify that only cgroup1 freezer uses PM freezer (Tejun Heo)
- Add document on debugging shutdown hangs to PM documentation and
correct a mistaken configuration option in it (Mario Limonciello)
- Shut down wakeup source timer before removing the wakeup source from
the list (Kaushlendra Kumar, Rafael Wysocki)
- Introduce new PMSG_POWEROFF event for system shutdown handling with
the help of PM device callbacks (Mario Limonciello)
- Make pm_test delay interruptible by wakeup events (Riwen Lu)
- Clean up kernel-doc comment style usage in the core hibernation
code and remove unuseful comments from it (Sunday Adelodun, Rafael
Wysocki)
- Add support for handling wakeup events and aborting the suspend
process while it is syncing file systems (Samuel Wu, Rafael Wysocki)
- Add WQ_UNBOUND to pm_wq workqueue (Marco Crivellari)
- Add runtime PM wrapper macros for ACQUIRE()/ACQUIRE_ERR() and use
them in the PCI core and the ACPI TAD driver (Rafael Wysocki)
- Improve runtime PM in the ACPI TAD driver (Rafael Wysocki)
- Update pm_runtime_allow/forbid() documentation (Rafael Wysocki)
- Fix typos in runtime.c comments (Malaya Kumar Rout)
- Move governor.h from devfreq under include/linux/ and rename to
devfreq-governor.h to allow devfreq governor definitions in out
of drivers/devfreq/ (Dmitry Baryshkov)
- Use min() to improve readability in tegra30-devfreq.c (Thorsten
Blum)
- Fix potential use-after-free issue of OPP handling in
hisi_uncore_freq.c (Pengjie Zhang)
- Fix typo in DFSO_DOWNDIFFERENTIAL macro name in
governor_simpleondemand.c in devfreq (Riwen Lu)
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Merge tag 'pm-6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management updates from Rafael Wysocki:
"There are quite a few interesting things here, including new hardware
support, new features, some bug fixes and documentation updates. In
addition, there are a usual bunch of minor fixes and cleanups all
over.
In the new hardware support category, there are intel_pstate and
intel_rapl driver updates to support new processors, Panther Lake,
Wildcat Lake, Noval Lake, and Diamond Rapids in the OOB mode, OPP and
bandwidth allocation support in the tegra186 cpufreq driver, and
JH7110S SOC support in dt-platdev cpufreq.
The new features are the PM QoS CPU latency limit for suspend-to-idle,
the netlink support for the energy model management, support for
terminating system suspend via a wakeup event during the sync of file
systems, configurable number of hibernation compression threads, the
runtime PM auto-cleanup macros, and the "poweroff" PM event that is
expected to be used during system shutdown.
Bugs are mostly fixed in cpuidle governors, but there are also fixes
elsewhere, like in the amd-pstate cpufreq driver.
Documentation updates include, but are not limited to, a new doc on
debugging shutdown hangs, cross-referencing fixes and cleanups in the
intel_pstate documentation, and updates of comments in the core
hibernation code.
Specifics:
- Introduce and document a QoS limit on CPU exit latency during
wakeup from suspend-to-idle (Ulf Hansson)
- Add support for building libcpupower statically (Zuo An)
- Add support for sending netlink notifications to user space on
energy model updates (Changwoo Mini, Peng Fan)
- Minor improvements to the Rust OPP interface (Tamir Duberstein)
- Fixes to scope-based pointers in the OPP library (Viresh Kumar)
- Use residency threshold in polling state override decisions in the
menu cpuidle governor (Aboorva Devarajan)
- Add sanity check for exit latency and target residency in the
cpufreq core (Rafael Wysocki)
- Use this_cpu_ptr() where possible in the teo governor (Christian
Loehle)
- Rework the handling of tick wakeups in the teo cpuidle governor to
increase the likelihood of stopping the scheduler tick in the cases
when tick wakeups can be counted as non-timer ones (Rafael Wysocki)
- Fix a reverse condition in the teo cpuidle governor and drop a
misguided target residency check from it (Rafael Wysocki)
- Clean up multiple minor defects in the teo cpuidle governor (Rafael
Wysocki)
- Update header inclusion to make it follow the Include What You Use
principle (Andy Shevchenko)
- Enable MSR-based RAPL PMU support in the intel_rapl power capping
driver and arrange for using it on the Panther Lake and Wildcat
Lake processors (Kuppuswamy Sathyanarayanan)
- Add support for Nova Lake and Wildcat Lake processors to the
intel_rapl power capping driver (Kaushlendra Kumar, Srinivas
Pandruvada)
- Add OPP and bandwidth support for Tegra186 (Aaron Kling)
- Optimizations for parameter array handling in the amd-pstate
cpufreq driver (Mario Limonciello)
- Fix for mode changes with offline CPUs in the amd-pstate cpufreq
driver (Gautham Shenoy)
- Preserve freq_table_sorted across suspend/hibernate in the cpufreq
core (Zihuan Zhang)
- Adjust energy model rules for Intel hybrid platforms in the
intel_pstate cpufreq driver and improve printing of debug messages
in it (Rafael Wysocki)
- Replace deprecated strcpy() in cpufreq_unregister_governor()
(Thorsten Blum)
- Fix duplicate hyperlink target errors in the intel_pstate cpufreq
driver documentation and use :ref: directive for internal linking
in it (Swaraj Gaikwad, Bagas Sanjaya)
- Add Diamond Rapids OOB mode support to the intel_pstate cpufreq
driver (Kuppuswamy Sathyanarayanan)
- Use mutex guard for driver locking in the intel_pstate driver and
eliminate some code duplication from it (Rafael Wysocki)
- Replace udelay() with usleep_range() in ACPI cpufreq (Kaushlendra
Kumar)
- Minor improvements to various cpufreq drivers (Christian Marangi,
Hal Feng, Jie Zhan, Marco Crivellari, Miaoqian Lin, and Shuhao Fu)
- Replace snprintf() with scnprintf() in show_trace_dev_match()
(Kaushlendra Kumar)
- Fix memory allocation error handling in pm_vt_switch_required()
(Malaya Kumar Rout)
- Introduce CALL_PM_OP() macro and use it to simplify code in generic
PM operations (Kaushlendra Kumar)
- Add module param to backtrace all CPUs in the device power
management watchdog (Sergey Senozhatsky)
- Rework message printing in swsusp_save() (Rafael Wysocki)
- Make it possible to change the number of hibernation compression
threads (Xueqin Luo)
- Clarify that only cgroup1 freezer uses PM freezer (Tejun Heo)
- Add document on debugging shutdown hangs to PM documentation and
correct a mistaken configuration option in it (Mario Limonciello)
- Shut down wakeup source timer before removing the wakeup source
from the list (Kaushlendra Kumar, Rafael Wysocki)
- Introduce new PMSG_POWEROFF event for system shutdown handling with
the help of PM device callbacks (Mario Limonciello)
- Make pm_test delay interruptible by wakeup events (Riwen Lu)
- Clean up kernel-doc comment style usage in the core hibernation
code and remove unuseful comments from it (Sunday Adelodun, Rafael
Wysocki)
- Add support for handling wakeup events and aborting the suspend
process while it is syncing file systems (Samuel Wu, Rafael
Wysocki)
- Add WQ_UNBOUND to pm_wq workqueue (Marco Crivellari)
- Add runtime PM wrapper macros for ACQUIRE()/ACQUIRE_ERR() and use
them in the PCI core and the ACPI TAD driver (Rafael Wysocki)
- Improve runtime PM in the ACPI TAD driver (Rafael Wysocki)
- Update pm_runtime_allow/forbid() documentation (Rafael Wysocki)
- Fix typos in runtime.c comments (Malaya Kumar Rout)
- Move governor.h from devfreq under include/linux/ and rename to
devfreq-governor.h to allow devfreq governor definitions in out of
drivers/devfreq/ (Dmitry Baryshkov)
- Use min() to improve readability in tegra30-devfreq.c (Thorsten
Blum)
- Fix potential use-after-free issue of OPP handling in
hisi_uncore_freq.c (Pengjie Zhang)
- Fix typo in DFSO_DOWNDIFFERENTIAL macro name in
governor_simpleondemand.c in devfreq (Riwen Lu)"
* tag 'pm-6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (96 commits)
PM / devfreq: Fix typo in DFSO_DOWNDIFFERENTIAL macro name
cpuidle: Warn instead of bailing out if target residency check fails
cpuidle: Update header inclusion
Documentation: power/cpuidle: Document the CPU system wakeup latency QoS
cpuidle: Respect the CPU system wakeup QoS limit for cpuidle
sched: idle: Respect the CPU system wakeup QoS limit for s2idle
pmdomain: Respect the CPU system wakeup QoS limit for cpuidle
pmdomain: Respect the CPU system wakeup QoS limit for s2idle
PM: QoS: Introduce a CPU system wakeup QoS limit
cpuidle: governors: teo: Add missing space to the description
PM: hibernate: Extra cleanup of comments in swap handling code
PM / devfreq: tegra30: use min to simplify actmon_cpu_to_emc_rate
PM / devfreq: hisi: Fix potential UAF in OPP handling
PM / devfreq: Move governor.h to a public header location
powercap: intel_rapl: Enable MSR-based RAPL PMU support
powercap: intel_rapl: Prepare read_raw() interface for atomic-context callers
cpufreq: qcom-nvmem: fix compilation warning for qcom_cpufreq_ipq806x_match_list
PM: sleep: Call pm_sleep_fs_sync() instead of ksys_sync_helper()
PM: sleep: Add support for wakeup during filesystem sync
cpufreq: ACPI: Replace udelay() with usleep_range()
...
- Prevent a thundering herd problem when the timekeeper CPU is delayed
and a large number of CPUs compete to acquire jiffies_lock to do the
update. Limit it to one CPU with a separate "uncontended" atomic
variable.
- A set of improvements for the timer migration mechanism:
- Support imbalanced NUMA trees correctly
- Support dynamic exclusion of CPUs from the migrator duty to allow the
cpuset/isolation mechanism to exclude them from handling timers of
remote idle CPUs.
- The usual small updates, cleanups and enhancements
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Merge tag 'timers-core-2025-11-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer core updates from Thomas Gleixner:
- Prevent a thundering herd problem when the timekeeper CPU is delayed
and a large number of CPUs compete to acquire jiffies_lock to do the
update. Limit it to one CPU with a separate "uncontended" atomic
variable.
- A set of improvements for the timer migration mechanism:
- Support imbalanced NUMA trees correctly
- Support dynamic exclusion of CPUs from the migrator duty to allow
the cpuset/isolation mechanism to exclude them from handling
timers of remote idle CPUs
- The usual small updates, cleanups and enhancements
* tag 'timers-core-2025-11-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
timers/migration: Exclude isolated cpus from hierarchy
cpumask: Add initialiser to use cleanup helpers
sched/isolation: Force housekeeping if isolcpus and nohz_full don't leave any
cgroup/cpuset: Rename update_unbound_workqueue_cpumask() to update_isolation_cpumasks()
timers/migration: Use scoped_guard on available flag set/clear
timers/migration: Add mask for CPUs available in the hierarchy
timers/migration: Rename 'online' bit to 'available'
selftests/timers/nanosleep: Add tests for return of remaining time
selftests/timers: Clean up kernel version check in posix_timers
time: Fix a few typos in time[r] related code comments
time: tick-oneshot: Add missing Return and parameter descriptions to kernel-doc
hrtimer: Store time as ktime_t in restart block
timers/migration: Remove dead code handling idle CPU checking for remote timers
timers/migration: Remove unused "cpu" parameter from tmigr_get_group()
timers/migration: Assert that hotplug preparing CPU is part of stable active hierarchy
timers/migration: Fix imbalanced NUMA trees
timers/migration: Remove locking on group connection
timers/migration: Convert "while" loops to use "for"
tick/sched: Limit non-timekeeper CPUs calling jiffies update
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Merge tag 'kernel-6.19-rc1.cred' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull cred guard updates from Christian Brauner:
"This contains substantial credential infrastructure improvements
adding guard-based credential management that simplifies code and
eliminates manual reference counting in many subsystems.
Features:
- Kernel Credential Guards
Add with_kernel_creds() and scoped_with_kernel_creds() guards that
allow using the kernel credentials without allocating and copying
them. This was requested by Linus after seeing repeated
prepare_kernel_creds() calls that duplicate the kernel credentials
only to drop them again later.
The new guards completely avoid the allocation and never expose the
temporary variable to hold the kernel credentials anywhere in
callers.
- Generic Credential Guards
Add scoped_with_creds() guards for the common override_creds() and
revert_creds() pattern. This builds on earlier work that made
override_creds()/revert_creds() completely reference count free.
- Prepare Credential Guards
Add prepare credential guards for the more complex pattern of
preparing a new set of credentials and overriding the current
credentials with them:
- prepare_creds()
- modify new creds
- override_creds()
- revert_creds()
- put_cred()
Cleanups:
- Make init_cred static since it should not be directly accessed
- Add kernel_cred() helper to properly access the kernel credentials
- Fix scoped_class() macro that was introduced two cycles ago
- coredump: split out do_coredump() from vfs_coredump() for cleaner
credential handling
- coredump: move revert_cred() before coredump_cleanup()
- coredump: mark struct mm_struct as const
- coredump: pass struct linux_binfmt as const
- sev-dev: use guard for path"
* tag 'kernel-6.19-rc1.cred' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (36 commits)
trace: use override credential guard
trace: use prepare credential guard
coredump: use override credential guard
coredump: use prepare credential guard
coredump: split out do_coredump() from vfs_coredump()
coredump: mark struct mm_struct as const
coredump: pass struct linux_binfmt as const
coredump: move revert_cred() before coredump_cleanup()
sev-dev: use override credential guards
sev-dev: use prepare credential guard
sev-dev: use guard for path
cred: add prepare credential guard
net/dns_resolver: use credential guards in dns_query()
cgroup: use credential guards in cgroup_attach_permissions()
act: use credential guards in acct_write_process()
smb: use credential guards in cifs_get_spnego_key()
nfs: use credential guards in nfs_idmap_get_key()
nfs: use credential guards in nfs_local_call_write()
nfs: use credential guards in nfs_local_call_read()
erofs: use credential guards
...
Currently, the check for whether a partition is populated does not
account for tasks in the cpuset of attaching. This is a corner case
that can leave a task stuck in a partition with no effective CPUs.
The race condition occurs as follows:
cpu0 cpu1
//cpuset A with cpu N
migrate task p to A
cpuset_can_attach
// with effective cpus
// check ok
// cpuset_mutex is not held // clear cpuset.cpus.exclusive
// making effective cpus empty
update_exclusive_cpumask
// tasks_nocpu_error check ok
// empty effective cpus, partition valid
cpuset_attach
...
// task p stays in A, with non-effective cpus.
To fix this issue, this patch introduces cs_is_populated, which considers
tasks in the attaching cpuset. This new helper is used in validate_change
and partition_is_populated.
Fixes: e2d59900d9 ("cgroup/cpuset: Allow no-task partition to have empty cpuset.cpus.effective")
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
The timer migration mechanism allows active CPUs to pull timers from
idle ones to improve the overall idle time. This is however undesired
when CPU intensive workloads run on isolated cores, as the algorithm
would move the timers from housekeeping to isolated cores, negatively
affecting the isolation.
Exclude isolated cores from the timer migration algorithm, extend the
concept of unavailable cores, currently used for offline ones, to
isolated ones:
* A core is unavailable if isolated or offline;
* A core is available if non isolated and online;
A core is considered unavailable as isolated if it belongs to:
* the isolcpus (domain) list
* an isolated cpuset
Except if it is:
* in the nohz_full list (already idle for the hierarchy)
* the nohz timekeeper core (must be available to handle global timers)
CPUs are added to the hierarchy during late boot, excluding isolated
ones, the hierarchy is also adapted when the cpuset isolation changes.
Due to how the timer migration algorithm works, any CPU part of the
hierarchy can have their global timers pulled by remote CPUs and have to
pull remote timers, only skipping pulling remote timers would break the
logic.
For this reason, prevent isolated CPUs from pulling remote global
timers, but also the other way around: any global timer started on an
isolated CPU will run there. This does not break the concept of
isolation (global timers don't come from outside the CPU) and, if
considered inappropriate, can usually be mitigated with other isolation
techniques (e.g. IRQ pinning).
This effect was noticed on a 128 cores machine running oslat on the
isolated cores (1-31,33-63,65-95,97-127). The tool monopolises CPUs,
and the CPU with lowest count in a timer migration hierarchy (here 1
and 65) appears as always active and continuously pulls global timers,
from the housekeeping CPUs. This ends up moving driver work (e.g.
delayed work) to isolated CPUs and causes latency spikes:
before the change:
# oslat -c 1-31,33-63,65-95,97-127 -D 62s
...
Maximum: 1203 10 3 4 ... 5 (us)
after the change:
# oslat -c 1-31,33-63,65-95,97-127 -D 62s
...
Maximum: 10 4 3 4 3 ... 5 (us)
The same behaviour was observed on a machine with as few as 20 cores /
40 threads with isocpus set to: 1-9,11-39 with rtla-osnoise-top.
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: John B. Wyatt IV <jwyatt@redhat.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://patch.msgid.link/20251120145653.296659-8-gmonaco@redhat.com
update_unbound_workqueue_cpumask() updates unbound workqueues settings
when there's a change in isolated CPUs, but it can be used for other
subsystems requiring updated when isolated CPUs change.
Generalise the name to update_isolation_cpumasks() to prepare for other
functions unrelated to workqueues to be called in that spot.
[longman: Change the function name to update_isolation_cpumasks()]
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Chen Ridong <chenridong@huaweicloud.com>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Waiman Long <longman@redhat.com>
Link: https://patch.msgid.link/20251120145653.296659-5-gmonaco@redhat.com
cpuset_cpus_allowed() uses a reader lock that is sleepable under RT,
which means it cannot be called inside raw_spin_lock_t context.
Introduce a new cpuset_cpus_allowed_locked() helper that performs the
same function as cpuset_cpus_allowed() except that the caller must have
acquired the cpuset_mutex so that no further locking will be needed.
Suggested-by: Waiman Long <longman@redhat.com>
Signed-off-by: Pingfan Liu <piliu@redhat.com>
Cc: Waiman Long <longman@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: linux-kernel@vger.kernel.org
To: cgroups@vger.kernel.org
Reviewed-by: Chen Ridong <chenridong@huawei.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
The kernel can throttle network sockets if the memory cgroup associated
with the corresponding socket is under memory pressure. The throttling
actions include clamping the transmit window, failing to expand receive or
send buffers, aggressively prune out-of-order receive queue, FIN deferred
to a retransmitted packet and more. Let's add memcg metric to track such
throttling actions.
At the moment memcg memory pressure is defined through vmpressure and in
future it may be defined using PSI or we may add more flexible way for the
users to define memory pressure, maybe through ebpf. However the
potential throttling actions will remain the same, so this newly
introduced metric will continue to track throttling actions irrespective
of how memcg memory pressure is defined.
Link: https://lkml.kernel.org/r/20251016161035.86161-1-shakeel.butt@linux.dev
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Daniel Sedlak <daniel.sedlak@cdn77.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kacinski <kuba@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Simon Horman <horms@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Previously, update_cpumasks_hier() used need_rebuild_sched_domains to
decide whether to invoke rebuild_sched_domains_locked(). Now that
rebuild_sched_domains_locked() only sets force_rebuild, the flag is
redundant. Hence, remove it.
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
The remote_children list is used to track all remote partitions attached
to a cpuset. However, it serves no other purpose. Using a boolean flag to
indicate whether a cpuset is a remote partition is a more direct approach,
making remote_children unnecessary.
This patch replaces the list with a remote_partition flag in the cpuset
structure and removes remote_children entirely.
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
There is no need to jump to the 'done' label upon failure, as no cleanup
is required. Return the error code directly instead.
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
To compile cgroup.c with PREEMPT_RT=y include header which declares
struct irq_work.
Fixes: 9311e6c29b ("cgroup: Fix sleeping from invalid context warning on PREEMPT_RT")
Signed-off-by: Bert Karwatzki <spasswolf@web.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
Bring in the shared branch with the kbuild tree to enable
'-fms-extensions' for 6.19. Further namespace cleanup work
requires this extension.
Signed-off-by: Christian Brauner <brauner@kernel.org>
cgroup_task_dead() is called from finish_task_switch() which runs with
preemption disabled and doesn't allow scheduling even on PREEMPT_RT. The
function needs to acquire css_set_lock which is a regular spinlock that can
sleep on RT kernels, leading to "sleeping function called from invalid
context" warnings.
css_set_lock is too large in scope to convert to a raw_spinlock. However,
the unlinking operations don't need to run synchronously - they just need
to complete after the task is done running.
On PREEMPT_RT, defer the work through irq_work. While the work doesn't need
to happen immediately, it can't be delayed indefinitely either as the dead
task pins the cgroup and task_struct can be pinned indefinitely. Use the
lazy version of irq_work to allow batching and lower impact while ensuring
timely completion.
v2: Use IRQ_WORK_INIT_LAZY instead of immediate irq_work and add explanation
for why the work can't be delayed indefinitely (Sebastian Andrzej Siewior).
Fixes: d245698d72 ("cgroup: Defer task cgroup unlink until after the task is done switching out")
Reported-by: Calvin Owens <calvin@wbinvd.org>
Link: https://lore.kernel.org/r/20251104181114.489391-1-calvin@wbinvd.org
Signed-off-by: Tejun Heo <tj@kernel.org>
The current cpuset code passes a local isolcpus_updated flag around in a
number of functions to determine if external isolation related cpumasks
like wq_unbound_cpumask should be updated. It is a bit cumbersome and
makes the code more complex. Simplify the code by using a global boolean
flag "isolated_cpus_updating" to track this. This flag will be set in
isolated_cpus_update() and cleared in update_isolation_cpumasks().
No functional change is expected.
Signed-off-by: Waiman Long <longman@redhat.com>
Reviewed-by: Chen Ridong <chenridong@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Commit 4a74e41888 ("cgroup/cpuset: Check partition conflict with
housekeeping setup") is supposed to ensure that domain isolated CPUs
designated by the "isolcpus" boot command line option stay either in
root partition or in isolated partitions. However, the required check
wasn't implemented when a remote partition was created or when an
existing partition changed type from "root" to "isolated".
Even though this is a relatively minor issue, we still need to add the
required prstate_housekeeping_conflict() call in the right places to
ensure that the rule is strictly followed.
The following steps can be used to reproduce the problem before this
fix.
# fmt -1 /proc/cmdline | grep isolcpus
isolcpus=9
# cd /sys/fs/cgroup/
# echo +cpuset > cgroup.subtree_control
# mkdir test
# echo 9 > test/cpuset.cpus
# echo isolated > test/cpuset.cpus.partition
# cat test/cpuset.cpus.partition
isolated
# cat test/cpuset.cpus.effective
9
# echo root > test/cpuset.cpus.partition
# cat test/cpuset.cpus.effective
9
# cat test/cpuset.cpus.partition
root
With this fix, the last few steps will become:
# echo root > test/cpuset.cpus.partition
# cat test/cpuset.cpus.effective
0-8,10-95
# cat test/cpuset.cpus.partition
root invalid (partition config conflicts with housekeeping setup)
Reported-by: Chen Ridong <chenridong@huawei.com>
Signed-off-by: Waiman Long <longman@redhat.com>
Reviewed-by: Chen Ridong <chenridong@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Move up the prstate_housekeeping_conflict() helper so that it can be
used in remote partition code.
Signed-off-by: Waiman Long <longman@redhat.com>
Reviewed-by: Chen Ridong <chenridong@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Currently the user can set up isolated cpus via cpuset and nohz_full in
such a way that leaves no housekeeping CPU (i.e. no CPU that is neither
domain isolated nor nohz full). This can be a problem for other
subsystems (e.g. the timer wheel imgration).
Prevent this configuration by blocking any assignation that would cause
the union of domain isolated cpus and nohz_full to covers all CPUs.
[longman: Remove isolated_cpus_should_update() and rewrite the checking
in update_prstate() and update_parent_effective_cpumask()]
Originally-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Waiman Long <longman@redhat.com>
Reviewed-by: Chen Ridong <chenridong@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
update_unbound_workqueue_cpumask() updates unbound workqueues settings
when there's a change in isolated CPUs, but it can be used for other
subsystems requiring updated when isolated CPUs change.
Generalise the name to update_isolation_cpumasks() to prepare for other
functions unrelated to workqueues to be called in that spot.
[longman: Change the function name to update_isolation_cpumasks()]
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Waiman Long <longman@redhat.com>
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Waiman Long <longman@redhat.com>
Reviewed-by: Chen Ridong <chenridong@huaweicloud.com>
Reviewed-by: Chen Ridong <chenridong@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
When a task exits, css_set_move_task(tsk, cset, NULL, false) unlinks the task
from its cgroup. From the cgroup's perspective, the task is now gone. If this
makes the cgroup empty, it can be removed, triggering ->css_offline() callbacks
that notify controllers the cgroup is going offline resource-wise.
However, the exiting task can still run, perform memory operations, and schedule
until the final context switch in finish_task_switch(). This creates a confusing
situation where controllers are told a cgroup is offline while resource
activities are still happening in it. While this hasn't broken existing
controllers, it has caused direct confusion for sched_ext schedulers.
Split cgroup_task_exit() into two functions. cgroup_task_exit() now only calls
the subsystem exit callbacks and continues to be called from do_exit(). The
css_set cleanup is moved to the new cgroup_task_dead() which is called from
finish_task_switch() after the final context switch, so that the cgroup only
appears empty after the task is truly done running.
This also reorders operations so that subsys->exit() is now called before
unlinking from the cgroup, which shouldn't break anything.
Cc: Dan Schatzberg <dschatzberg@meta.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Currently, cgroup_task_exit() adds thread group leaders with live member
threads to their css_set's dying_tasks list (so cgroup.procs iteration can
still see the leader), and cgroup_task_release() later removes them with
list_del_init(&task->cg_list).
An upcoming patch will defer the dying_tasks list addition, moving it from
cgroup_task_exit() (called from do_exit()) to a new function called from
finish_task_switch(). However, release_task() (which calls
cgroup_task_release()) can run either before or after finish_task_switch(),
creating a race where cgroup_task_release() might try to remove the task from
dying_tasks before or while it's being added.
Move the list_del_init() from cgroup_task_release() to cgroup_task_free() to
fix this race. cgroup_task_free() runs from __put_task_struct(), which is
always after both paths, making the cleanup safe.
Cc: Dan Schatzberg <dschatzberg@meta.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
The current names cgroup_exit(), cgroup_release(), and cgroup_free() are
confusing because they look like they're operating on cgroups themselves when
they're actually task lifecycle hooks. For example, cgroup_init() initializes
the cgroup subsystem while cgroup_exit() is a task exit notification to
cgroup. Rename them to cgroup_task_exit(), cgroup_task_release(), and
cgroup_task_free() to make it clear that these operate on tasks.
Cc: Dan Schatzberg <dschatzberg@meta.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Chen Ridong <chenridong@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
The current naming is very misleading as this really isn't exiting all
of the task's namespaces. It is only exiting the namespaces that hang of
off nsproxy. Reflect that in the name.
Link: https://patch.msgid.link/20251029-work-namespace-nstree-listns-v4-10-2e6f823ebdc0@kernel.org
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
cgroup1 freezer piggybacks on the PM freezer, which inadvertently allowed
userspace to produce uninterruptible tasks at will. To avoid the issue,
cgroup2 freezer switched to a separate job control based mechanism. While
this happened a long time ago, the code and comment haven't been updated
making it confusing to people who aren't familiar with the history.
Rename cgroup_freezing() to cgroup1_freezing() and update comments on top of
freezing() and frozen() to clarify that cgroup2 freezer isn't covered by the
PM freezer mechanism.
Signed-off-by: Tejun Heo <tj@kernel.org>
Suggested-by: Qu Wenruo <wqu@suse.com>
Link: https://patch.msgid.link/aPZ3q6Hm865NicBC@slm.duckdns.org
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Linus Torvalds