Each cset (css_set) is pinned by its tasks. When we're moving tasks around
across csets for a migration, we need to hold the source and destination
csets to ensure that they don't go away while we're moving tasks about. This
is done by linking cset->mg_preload_node on either the
mgctx->preloaded_src_csets or mgctx->preloaded_dst_csets list. Using the
same cset->mg_preload_node for both the src and dst lists was deemed okay as
a cset can't be both the source and destination at the same time.
Unfortunately, this overloading becomes problematic when multiple tasks are
involved in a migration and some of them are identity noop migrations while
others are actually moving across cgroups. For example, this can happen with
the following sequence on cgroup1:
#1> mkdir -p /sys/fs/cgroup/misc/a/b
#2> echo $$ > /sys/fs/cgroup/misc/a/cgroup.procs
#3> RUN_A_COMMAND_WHICH_CREATES_MULTIPLE_THREADS &
#4> PID=$!
#5> echo $PID > /sys/fs/cgroup/misc/a/b/tasks
#6> echo $PID > /sys/fs/cgroup/misc/a/cgroup.procs
the process including the group leader back into a. In this final migration,
non-leader threads would be doing identity migration while the group leader
is doing an actual one.
After #3, let's say the whole process was in cset A, and that after #4, the
leader moves to cset B. Then, during #6, the following happens:
1. cgroup_migrate_add_src() is called on B for the leader.
2. cgroup_migrate_add_src() is called on A for the other threads.
3. cgroup_migrate_prepare_dst() is called. It scans the src list.
4. It notices that B wants to migrate to A, so it tries to A to the dst
list but realizes that its ->mg_preload_node is already busy.
5. and then it notices A wants to migrate to A as it's an identity
migration, it culls it by list_del_init()'ing its ->mg_preload_node and
putting references accordingly.
6. The rest of migration takes place with B on the src list but nothing on
the dst list.
This means that A isn't held while migration is in progress. If all tasks
leave A before the migration finishes and the incoming task pins it, the
cset will be destroyed leading to use-after-free.
This is caused by overloading cset->mg_preload_node for both src and dst
preload lists. We wanted to exclude the cset from the src list but ended up
inadvertently excluding it from the dst list too.
This patch fixes the issue by separating out cset->mg_preload_node into
->mg_src_preload_node and ->mg_dst_preload_node, so that the src and dst
preloadings don't interfere with each other.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Mukesh Ojha <quic_mojha@quicinc.com>
Reported-by: shisiyuan <shisiyuan19870131@gmail.com>
Link: http://lkml.kernel.org/r/1654187688-27411-1-git-send-email-shisiyuan@xiaomi.com
Link: https://www.spinics.net/lists/cgroups/msg33313.html
Fixes: f817de9851 ("cgroup: prepare migration path for unified hierarchy")
Cc: stable@vger.kernel.org # v3.16+
Pull cgroup updates from Tejun Heo:
"Nothing too interesting. This adds cpu controller selftests and there
are a couple code cleanup patches"
* 'for-5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup: remove the superfluous judgment
cgroup: Make cgroup_debug static
kseltest/cgroup: Make test_stress.sh work if run interactively
kselftest/cgroup: fix test_stress.sh to use OUTPUT dir
cgroup: Add config file to cgroup selftest suite
cgroup: Add test_cpucg_max_nested() testcase
cgroup: Add test_cpucg_max() testcase
cgroup: Add test_cpucg_nested_weight_underprovisioned() testcase
cgroup: Adding test_cpucg_nested_weight_overprovisioned() testcase
cgroup: Add test_cpucg_weight_underprovisioned() testcase
cgroup: Add test_cpucg_weight_overprovisioned() testcase
cgroup: Add test_cpucg_stats() testcase to cgroup cpu selftests
cgroup: Add new test_cpu.c test suite in cgroup selftests
Remove the superfluous judgment since the function is
never called for a root cgroup, as suggested by Tejun.
Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Shida Zhang <zhangshida@kylinos.cn>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Make cgroup_debug static since it's only used in cgroup.c
Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
There are 3 places where the cpu and node masks of the top cpuset can
be initialized in the order they are executed:
1) start_kernel -> cpuset_init()
2) start_kernel -> cgroup_init() -> cpuset_bind()
3) kernel_init_freeable() -> do_basic_setup() -> cpuset_init_smp()
The first cpuset_init() call just sets all the bits in the masks.
The second cpuset_bind() call sets cpus_allowed and mems_allowed to the
default v2 values. The third cpuset_init_smp() call sets them back to
v1 values.
For systems with cgroup v2 setup, cpuset_bind() is called once. As a
result, cpu and memory node hot add may fail to update the cpu and node
masks of the top cpuset to include the newly added cpu or node in a
cgroup v2 environment.
For systems with cgroup v1 setup, cpuset_bind() is called again by
rebind_subsystem() when the v1 cpuset filesystem is mounted as shown
in the dmesg log below with an instrumented kernel.
[ 2.609781] cpuset_bind() called - v2 = 1
[ 3.079473] cpuset_init_smp() called
[ 7.103710] cpuset_bind() called - v2 = 0
smp_init() is called after the first two init functions. So we don't
have a complete list of active cpus and memory nodes until later in
cpuset_init_smp() which is the right time to set up effective_cpus
and effective_mems.
To fix this cgroup v2 mask setup problem, the potentially incorrect
cpus_allowed & mems_allowed setting in cpuset_init_smp() are removed.
For cgroup v2 systems, the initial cpuset_bind() call will set the masks
correctly. For cgroup v1 systems, the second call to cpuset_bind()
will do the right setup.
cc: stable@vger.kernel.org
Signed-off-by: Waiman Long <longman@redhat.com>
Tested-by: Feng Tang <feng.tang@intel.com>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Here is the set of driver core changes for 5.18-rc1.
Not much here, primarily it was a bunch of cleanups and small updates:
- kobj_type cleanups for default_groups
- documentation updates
- firmware loader minor changes
- component common helper added and take advantage of it in many
drivers (the largest part of this pull request).
There will be a merge conflict in drivers/power/supply/ab8500_chargalg.c
with your tree, the merge conflict should be easy (take all the
changes).
All of these have been in linux-next for a while with no reported
problems.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core updates from Greg KH:
"Here is the set of driver core changes for 5.18-rc1.
Not much here, primarily it was a bunch of cleanups and small updates:
- kobj_type cleanups for default_groups
- documentation updates
- firmware loader minor changes
- component common helper added and take advantage of it in many
drivers (the largest part of this pull request).
All of these have been in linux-next for a while with no reported
problems"
* tag 'driver-core-5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (54 commits)
Documentation: update stable review cycle documentation
drivers/base/dd.c : Remove the initial value of the global variable
Documentation: update stable tree link
Documentation: add link to stable release candidate tree
devres: fix typos in comments
Documentation: add note block surrounding security patch note
samples/kobject: Use sysfs_emit instead of sprintf
base: soc: Make soc_device_match() simpler and easier to read
driver core: dd: fix return value of __setup handler
driver core: Refactor sysfs and drv/bus remove hooks
driver core: Refactor multiple copies of device cleanup
scripts: get_abi.pl: Fix typo in help message
kernfs: fix typos in comments
kernfs: remove unneeded #if 0 guard
ALSA: hda/realtek: Make use of the helper component_compare_dev_name
video: omapfb: dss: Make use of the helper component_compare_dev
power: supply: ab8500: Make use of the helper component_compare_dev
ASoC: codecs: wcd938x: Make use of the helper component_compare/release_of
iommu/mediatek: Make use of the helper component_compare/release_of
drm: of: Make use of the helper component_release_of
...
Merge more updates from Andrew Morton:
"Various misc subsystems, before getting into the post-linux-next
material.
41 patches.
Subsystems affected by this patch series: procfs, misc, core-kernel,
lib, checkpatch, init, pipe, minix, fat, cgroups, kexec, kdump,
taskstats, panic, kcov, resource, and ubsan"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (41 commits)
Revert "ubsan, kcsan: Don't combine sanitizer with kcov on clang"
kernel/resource: fix kfree() of bootmem memory again
kcov: properly handle subsequent mmap calls
kcov: split ioctl handling into locked and unlocked parts
panic: move panic_print before kmsg dumpers
panic: add option to dump all CPUs backtraces in panic_print
docs: sysctl/kernel: add missing bit to panic_print
taskstats: remove unneeded dead assignment
kasan: no need to unset panic_on_warn in end_report()
ubsan: no need to unset panic_on_warn in ubsan_epilogue()
panic: unset panic_on_warn inside panic()
docs: kdump: add scp example to write out the dump file
docs: kdump: update description about sysfs file system support
arm64: mm: use IS_ENABLED(CONFIG_KEXEC_CORE) instead of #ifdef
x86/setup: use IS_ENABLED(CONFIG_KEXEC_CORE) instead of #ifdef
riscv: mm: init: use IS_ENABLED(CONFIG_KEXEC_CORE) instead of #ifdef
kexec: make crashk_res, crashk_low_res and crash_notes symbols always visible
cgroup: use irqsave in cgroup_rstat_flush_locked().
fat: use pointer to simple type in put_user()
minix: fix bug when opening a file with O_DIRECT
...
All callers of cgroup_rstat_flush_locked() acquire cgroup_rstat_lock
either with spin_lock_irq() or spin_lock_irqsave().
cgroup_rstat_flush_locked() itself acquires cgroup_rstat_cpu_lock which
is a raw_spin_lock. This lock is also acquired in
cgroup_rstat_updated() in IRQ context and therefore requires _irqsave()
locking suffix in cgroup_rstat_flush_locked().
Since there is no difference between spin_lock_t and raw_spin_lock_t on
!RT lockdep does not complain here. On RT lockdep complains because the
interrupts were not disabled here and a deadlock is possible.
Acquire the raw_spin_lock_t with disabled interrupts.
Link: https://lkml.kernel.org/r/20220301122143.1521823-2-bigeasy@linutronix.de
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Zefan Li <lizefan.x@bytedance.com>
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Subject: cgroup: add a comment to cgroup_rstat_flush_locked().
Add a comment why spin_lock_irq() -> raw_spin_lock_irqsave() is needed.
Link: https://lkml.kernel.org/r/Yh+DOK73hfVV5ThX@linutronix.de
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Zefan Li <lizefan.x@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull cgroup updates from Tejun Heo:
"All trivial cleanups without meaningful behavior changes"
* 'for-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup: cleanup comments
cgroup: Fix cgroup_can_fork() and cgroup_post_fork() kernel-doc comment
cgroup: rstat: retrieve current bstat to delta directly
cgroup: rstat: use same convention to assign cgroup_base_stat
for spdx, add a space before //
replacements
judgement to judgment
transofrmed to transformed
partitition to partition
histrical to historical
migratecd to migrated
Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
There is no need to have struct kernfs_root be part of kernfs.h for
the whole kernel to see and poke around it. Move it internal to kernfs
code and provide a helper function, kernfs_root_to_node(), to handle the
one field that kernfs users were directly accessing from the structure.
Cc: Imran Khan <imran.f.khan@oracle.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20220222070713.3517679-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull cgroup fixes from Tejun Heo:
- Fix for a subtle bug in the recent release_agent permission check
update
- Fix for a long-standing race condition between cpuset and cpu hotplug
- Comment updates
* 'for-5.17-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cpuset: Fix kernel-doc
cgroup-v1: Correct privileges check in release_agent writes
cgroup: clarify cgroup_css_set_fork()
cgroup/cpuset: Fix a race between cpuset_attach() and cpu hotplug
Fix the following W=1 kernel warnings:
kernel/cgroup/cpuset.c:3718: warning: expecting prototype for
cpuset_memory_pressure_bump(). Prototype was for
__cpuset_memory_pressure_bump() instead.
kernel/cgroup/cpuset.c:3568: warning: expecting prototype for
cpuset_node_allowed(). Prototype was for __cpuset_node_allowed()
instead.
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
The idea is to check: a) the owning user_ns of cgroup_ns, b)
capabilities in init_user_ns.
The commit 24f6008564 ("cgroup-v1: Require capabilities to set
release_agent") got this wrong in the write handler of release_agent
since it checked user_ns of the opener (may be different from the owning
user_ns of cgroup_ns).
Secondly, to avoid possibly confused deputy, the capability of the
opener must be checked.
Fixes: 24f6008564 ("cgroup-v1: Require capabilities to set release_agent")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/stable/20220216121142.GB30035@blackbody.suse.cz/
Signed-off-by: Michal Koutný <mkoutny@suse.com>
Reviewed-by: Masami Ichikawa(CIP) <masami.ichikawa@cybertrust.co.jp>
Signed-off-by: Tejun Heo <tj@kernel.org>
With recent fixes for the permission checking when moving a task into a cgroup
using a file descriptor to a cgroup's cgroup.procs file and calling write() it
seems a good idea to clarify CLONE_INTO_CGROUP permission checking with a
comment.
Cc: Tejun Heo <tj@kernel.org>
Cc: <cgroups@vger.kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
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Merge tag 'v5.17-rc5' into sched/core, to resolve conflicts
New conflicts in sched/core due to the following upstream fixes:
44585f7bc0 ("psi: fix "defined but not used" warnings when CONFIG_PROC_FS=n")
a06247c680 ("psi: Fix uaf issue when psi trigger is destroyed while being polled")
Conflicts:
include/linux/psi_types.h
kernel/sched/psi.c
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Refer to housekeeping APIs using single feature types instead of flags.
This prevents from passing multiple isolation features at once to
housekeeping interfaces, which soon won't be possible anymore as each
isolation features will have their own cpumask.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Juri Lelli <juri.lelli@redhat.com>
Reviewed-by: Phil Auld <pauld@redhat.com>
Link: https://lore.kernel.org/r/20220207155910.527133-5-frederic@kernel.org
As previously discussed(https://lkml.org/lkml/2022/1/20/51),
cpuset_attach() is affected with similar cpu hotplug race,
as follow scenario:
cpuset_attach() cpu hotplug
--------------------------- ----------------------
down_write(cpuset_rwsem)
guarantee_online_cpus() // (load cpus_attach)
sched_cpu_deactivate
set_cpu_active()
// will change cpu_active_mask
set_cpus_allowed_ptr(cpus_attach)
__set_cpus_allowed_ptr_locked()
// (if the intersection of cpus_attach and
cpu_active_mask is empty, will return -EINVAL)
up_write(cpuset_rwsem)
To avoid races such as described above, protect cpuset_attach() call
with cpu_hotplug_lock.
Fixes: be367d0992 ("cgroups: let ss->can_attach and ss->attach do whole threadgroups at a time")
Cc: stable@vger.kernel.org # v2.6.32+
Reported-by: Zhao Gongyi <zhaogongyi@huawei.com>
Signed-off-by: Zhang Qiao <zhangqiao22@huawei.com>
Acked-by: Waiman Long <longman@redhat.com>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Pull cgroup fixes from Tejun Heo:
- Eric's fix for a long standing cgroup1 permission issue where it only
checks for uid 0 instead of CAP which inadvertently allows
unprivileged userns roots to modify release_agent userhelper
- Fixes for the fallout from Waiman's recent cpuset work
* 'for-5.17-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup/cpuset: Fix "suspicious RCU usage" lockdep warning
cgroup-v1: Require capabilities to set release_agent
cpuset: Fix the bug that subpart_cpus updated wrongly in update_cpumask()
cgroup/cpuset: Make child cpusets restrict parents on v1 hierarchy
It was found that a "suspicious RCU usage" lockdep warning was issued
with the rcu_read_lock() call in update_sibling_cpumasks(). It is
because the update_cpumasks_hier() function may sleep. So we have
to release the RCU lock, call update_cpumasks_hier() and reacquire
it afterward.
Also add a percpu_rwsem_assert_held() in update_sibling_cpumasks()
instead of stating that in the comment.
Fixes: 4716909cc5 ("cpuset: Track cpusets that use parent's effective_cpus")
Signed-off-by: Waiman Long <longman@redhat.com>
Tested-by: Phil Auld <pauld@redhat.com>
Reviewed-by: Phil Auld <pauld@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
The cgroup release_agent is called with call_usermodehelper. The function
call_usermodehelper starts the release_agent with a full set fo capabilities.
Therefore require capabilities when setting the release_agaent.
Reported-by: Tabitha Sable <tabitha.c.sable@gmail.com>
Tested-by: Tabitha Sable <tabitha.c.sable@gmail.com>
Fixes: 81a6a5cdd2 ("Task Control Groups: automatic userspace notification of idle cgroups")
Cc: stable@vger.kernel.org # v2.6.24+
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
subparts_cpus should be limited as a subset of cpus_allowed, but it is
updated wrongly by using cpumask_andnot(). Use cpumask_and() instead to
fix it.
Fixes: ee8dde0cd2 ("cpuset: Add new v2 cpuset.sched.partition flag")
Signed-off-by: Tianchen Ding <dtcccc@linux.alibaba.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
With write operation on psi files replacing old trigger with a new one,
the lifetime of its waitqueue is totally arbitrary. Overwriting an
existing trigger causes its waitqueue to be freed and pending poll()
will stumble on trigger->event_wait which was destroyed.
Fix this by disallowing to redefine an existing psi trigger. If a write
operation is used on a file descriptor with an already existing psi
trigger, the operation will fail with EBUSY error.
Also bypass a check for psi_disabled in the psi_trigger_destroy as the
flag can be flipped after the trigger is created, leading to a memory
leak.
Fixes: 0e94682b73 ("psi: introduce psi monitor")
Reported-by: syzbot+cdb5dd11c97cc532efad@syzkaller.appspotmail.com
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Analyzed-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20220111232309.1786347-1-surenb@google.com
The commit 1f1562fcd0 ("cgroup/cpuset: Don't let child cpusets
restrict parent in default hierarchy") inteded to relax the check only
on the default hierarchy (or v2 mode) but it dropped the check in v1
too.
This patch returns and separates the legacy-only validations so that
they can be considered only in the v1 mode, which should enforce the old
constraints for the sake of compatibility.
Fixes: 1f1562fcd0 ("cgroup/cpuset: Don't let child cpusets restrict parent in default hierarchy")
Suggested-by: Waiman Long <longman@redhat.com>
Signed-off-by: Michal Koutný <mkoutny@suse.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Add the description of @kargs in cgroup_can_fork() and
cgroup_post_fork() kernel-doc comment to remove warnings found
by running scripts/kernel-doc, which is caused by using 'make W=1'.
kernel/cgroup/cgroup.c:6235: warning: Function parameter or member
'kargs' not described in 'cgroup_can_fork'
kernel/cgroup/cgroup.c:6296: warning: Function parameter or member
'kargs' not described in 'cgroup_post_fork'
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Instead of retrieve current bstat to cur and copy it to delta, let's use
delta directly.
This saves one copy operation and has the same code convention as
propagating delta to parent.
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
In function cgroup_base_stat_flush(), we update cgroup_base_stat by
getting rstatc->bstat and adjust delta to related fields.
There are two convention to assign cgroup_base_stat in this function:
* rstat2 = rstat1
* rstat2.cputime = rstat1.cputime
The second convention may make audience think just field "cputime" is
updated, while cputime is the only field in cgroup_base_stat.
Let's use the same convention to eliminate this confusion.
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Pull cgroup updates from Tejun Heo:
"Nothing too interesting. The only two noticeable changes are a subtle
cpuset behavior fix and trace event id field being expanded to u64
from int. Most others are code cleanups"
* 'for-5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cpuset: convert 'allowed' in __cpuset_node_allowed() to be boolean
cgroup/rstat: check updated_next only for root
cgroup: rstat: explicitly put loop variant in while
cgroup: return early if it is already on preloaded list
cgroup/cpuset: Don't let child cpusets restrict parent in default hierarchy
cgroup: Trace event cgroup id fields should be u64
cgroup: fix a typo in comment
cgroup: get the wrong css for css_alloc() during cgroup_init_subsys()
cgroup: rstat: Mark benign data race to silence KCSAN
Core
----
- Defer freeing TCP skbs to the BH handler, whenever possible,
or at least perform the freeing outside of the socket lock section
to decrease cross-CPU allocator work and improve latency.
- Add netdevice refcount tracking to locate sources of netdevice
and net namespace refcount leaks.
- Make Tx watchdog less intrusive - avoid pausing Tx and restarting
all queues from a single CPU removing latency spikes.
- Various small optimizations throughout the stack from Eric Dumazet.
- Make netdev->dev_addr[] constant, force modifications to go via
appropriate helpers to allow us to keep addresses in ordered data
structures.
- Replace unix_table_lock with per-hash locks, improving performance
of bind() calls.
- Extend skb drop tracepoint with a drop reason.
- Allow SO_MARK and SO_PRIORITY setsockopt under CAP_NET_RAW.
BPF
---
- New helpers:
- bpf_find_vma(), find and inspect VMAs for profiling use cases
- bpf_loop(), runtime-bounded loop helper trading some execution
time for much faster (if at all converging) verification
- bpf_strncmp(), improve performance, avoid compiler flakiness
- bpf_get_func_arg(), bpf_get_func_ret(), bpf_get_func_arg_cnt()
for tracing programs, all inlined by the verifier
- Support BPF relocations (CO-RE) in the kernel loader.
- Further the support for BTF_TYPE_TAG annotations.
- Allow access to local storage in sleepable helpers.
- Convert verifier argument types to a composable form with different
attributes which can be shared across types (ro, maybe-null).
- Prepare libbpf for upcoming v1.0 release by cleaning up APIs,
creating new, extensible ones where missing and deprecating those
to be removed.
Protocols
---------
- WiFi (mac80211/cfg80211):
- notify user space about long "come back in N" AP responses,
allow it to react to such temporary rejections
- allow non-standard VHT MCS 10/11 rates
- use coarse time in airtime fairness code to save CPU cycles
- Bluetooth:
- rework of HCI command execution serialization to use a common
queue and work struct, and improve handling errors reported
in the middle of a batch of commands
- rework HCI event handling to use skb_pull_data, avoiding packet
parsing pitfalls
- support AOSP Bluetooth Quality Report
- SMC:
- support net namespaces, following the RDMA model
- improve connection establishment latency by pre-clearing buffers
- introduce TCP ULP for automatic redirection to SMC
- Multi-Path TCP:
- support ioctls: SIOCINQ, OUTQ, and OUTQNSD
- support socket options: IP_TOS, IP_FREEBIND, IP_TRANSPARENT,
IPV6_FREEBIND, and IPV6_TRANSPARENT, TCP_CORK and TCP_NODELAY
- support cmsgs: TCP_INQ
- improvements in the data scheduler (assigning data to subflows)
- support fastclose option (quick shutdown of the full MPTCP
connection, similar to TCP RST in regular TCP)
- MCTP (Management Component Transport) over serial, as defined by
DMTF spec DSP0253 - "MCTP Serial Transport Binding".
Driver API
----------
- Support timestamping on bond interfaces in active/passive mode.
- Introduce generic phylink link mode validation for drivers which
don't have any quirks and where MAC capability bits fully express
what's supported. Allow PCS layer to participate in the validation.
Convert a number of drivers.
- Add support to set/get size of buffers on the Rx rings and size of
the tx copybreak buffer via ethtool.
- Support offloading TC actions as first-class citizens rather than
only as attributes of filters, improve sharing and device resource
utilization.
- WiFi (mac80211/cfg80211):
- support forwarding offload (ndo_fill_forward_path)
- support for background radar detection hardware
- SA Query Procedures offload on the AP side
New hardware / drivers
----------------------
- tsnep - FPGA based TSN endpoint Ethernet MAC used in PLCs with
real-time requirements for isochronous communication with protocols
like OPC UA Pub/Sub.
- Qualcomm BAM-DMUX WWAN - driver for data channels of modems
integrated into many older Qualcomm SoCs, e.g. MSM8916 or
MSM8974 (qcom_bam_dmux).
- Microchip LAN966x multi-port Gigabit AVB/TSN Ethernet Switch
driver with support for bridging, VLANs and multicast forwarding
(lan966x).
- iwlmei driver for co-operating between Intel's WiFi driver and
Intel's Active Management Technology (AMT) devices.
- mse102x - Vertexcom MSE102x Homeplug GreenPHY chips
- Bluetooth:
- MediaTek MT7921 SDIO devices
- Foxconn MT7922A
- Realtek RTL8852AE
Drivers
-------
- Significantly improve performance in the datapaths of:
lan78xx, ax88179_178a, lantiq_xrx200, bnxt.
- Intel Ethernet NICs:
- igb: support PTP/time PEROUT and EXTTS SDP functions on
82580/i354/i350 adapters
- ixgbevf: new PF -> VF mailbox API which avoids the risk of
mailbox corruption with ESXi
- iavf: support configuration of VLAN features of finer granularity,
stacked tags and filtering
- ice: PTP support for new E822 devices with sub-ns precision
- ice: support firmware activation without reboot
- Mellanox Ethernet NICs (mlx5):
- expose control over IRQ coalescing mode (CQE vs EQE) via ethtool
- support TC forwarding when tunnel encap and decap happen between
two ports of the same NIC
- dynamically size and allow disabling various features to save
resources for running in embedded / SmartNIC scenarios
- Broadcom Ethernet NICs (bnxt):
- use page frag allocator to improve Rx performance
- expose control over IRQ coalescing mode (CQE vs EQE) via ethtool
- Other Ethernet NICs:
- amd-xgbe: add Ryzen 6000 (Yellow Carp) Ethernet support
- Microsoft cloud/virtual NIC (mana):
- add XDP support (PASS, DROP, TX)
- Mellanox Ethernet switches (mlxsw):
- initial support for Spectrum-4 ASICs
- VxLAN with IPv6 underlay
- Marvell Ethernet switches (prestera):
- support flower flow templates
- add basic IP forwarding support
- NXP embedded Ethernet switches (ocelot & felix):
- support Per-Stream Filtering and Policing (PSFP)
- enable cut-through forwarding between ports by default
- support FDMA to improve packet Rx/Tx to CPU
- Other embedded switches:
- hellcreek: improve trapping management (STP and PTP) packets
- qca8k: support link aggregation and port mirroring
- Qualcomm 802.11ax WiFi (ath11k):
- qca6390, wcn6855: enable 802.11 power save mode in station mode
- BSS color change support
- WCN6855 hw2.1 support
- 11d scan offload support
- scan MAC address randomization support
- full monitor mode, only supported on QCN9074
- qca6390/wcn6855: report signal and tx bitrate
- qca6390: rfkill support
- qca6390/wcn6855: regdb.bin support
- Intel WiFi (iwlwifi):
- support SAR GEO Offset Mapping (SGOM) and Time-Aware-SAR (TAS)
in cooperation with the BIOS
- support for Optimized Connectivity Experience (OCE) scan
- support firmware API version 68
- lots of preparatory work for the upcoming Bz device family
- MediaTek WiFi (mt76):
- Specific Absorption Rate (SAR) support
- mt7921: 160 MHz channel support
- RealTek WiFi (rtw88):
- Specific Absorption Rate (SAR) support
- scan offload
- Other WiFi NICs
- ath10k: support fetching (pre-)calibration data from nvmem
- brcmfmac: configure keep-alive packet on suspend
- wcn36xx: beacon filter support
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag '5.17-net-next' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next
Pull networking updates from Jakub Kicinski:
"Core
----
- Defer freeing TCP skbs to the BH handler, whenever possible, or at
least perform the freeing outside of the socket lock section to
decrease cross-CPU allocator work and improve latency.
- Add netdevice refcount tracking to locate sources of netdevice and
net namespace refcount leaks.
- Make Tx watchdog less intrusive - avoid pausing Tx and restarting
all queues from a single CPU removing latency spikes.
- Various small optimizations throughout the stack from Eric Dumazet.
- Make netdev->dev_addr[] constant, force modifications to go via
appropriate helpers to allow us to keep addresses in ordered data
structures.
- Replace unix_table_lock with per-hash locks, improving performance
of bind() calls.
- Extend skb drop tracepoint with a drop reason.
- Allow SO_MARK and SO_PRIORITY setsockopt under CAP_NET_RAW.
BPF
---
- New helpers:
- bpf_find_vma(), find and inspect VMAs for profiling use cases
- bpf_loop(), runtime-bounded loop helper trading some execution
time for much faster (if at all converging) verification
- bpf_strncmp(), improve performance, avoid compiler flakiness
- bpf_get_func_arg(), bpf_get_func_ret(), bpf_get_func_arg_cnt()
for tracing programs, all inlined by the verifier
- Support BPF relocations (CO-RE) in the kernel loader.
- Further the support for BTF_TYPE_TAG annotations.
- Allow access to local storage in sleepable helpers.
- Convert verifier argument types to a composable form with different
attributes which can be shared across types (ro, maybe-null).
- Prepare libbpf for upcoming v1.0 release by cleaning up APIs,
creating new, extensible ones where missing and deprecating those
to be removed.
Protocols
---------
- WiFi (mac80211/cfg80211):
- notify user space about long "come back in N" AP responses,
allow it to react to such temporary rejections
- allow non-standard VHT MCS 10/11 rates
- use coarse time in airtime fairness code to save CPU cycles
- Bluetooth:
- rework of HCI command execution serialization to use a common
queue and work struct, and improve handling errors reported in
the middle of a batch of commands
- rework HCI event handling to use skb_pull_data, avoiding packet
parsing pitfalls
- support AOSP Bluetooth Quality Report
- SMC:
- support net namespaces, following the RDMA model
- improve connection establishment latency by pre-clearing buffers
- introduce TCP ULP for automatic redirection to SMC
- Multi-Path TCP:
- support ioctls: SIOCINQ, OUTQ, and OUTQNSD
- support socket options: IP_TOS, IP_FREEBIND, IP_TRANSPARENT,
IPV6_FREEBIND, and IPV6_TRANSPARENT, TCP_CORK and TCP_NODELAY
- support cmsgs: TCP_INQ
- improvements in the data scheduler (assigning data to subflows)
- support fastclose option (quick shutdown of the full MPTCP
connection, similar to TCP RST in regular TCP)
- MCTP (Management Component Transport) over serial, as defined by
DMTF spec DSP0253 - "MCTP Serial Transport Binding".
Driver API
----------
- Support timestamping on bond interfaces in active/passive mode.
- Introduce generic phylink link mode validation for drivers which
don't have any quirks and where MAC capability bits fully express
what's supported. Allow PCS layer to participate in the validation.
Convert a number of drivers.
- Add support to set/get size of buffers on the Rx rings and size of
the tx copybreak buffer via ethtool.
- Support offloading TC actions as first-class citizens rather than
only as attributes of filters, improve sharing and device resource
utilization.
- WiFi (mac80211/cfg80211):
- support forwarding offload (ndo_fill_forward_path)
- support for background radar detection hardware
- SA Query Procedures offload on the AP side
New hardware / drivers
----------------------
- tsnep - FPGA based TSN endpoint Ethernet MAC used in PLCs with
real-time requirements for isochronous communication with protocols
like OPC UA Pub/Sub.
- Qualcomm BAM-DMUX WWAN - driver for data channels of modems
integrated into many older Qualcomm SoCs, e.g. MSM8916 or MSM8974
(qcom_bam_dmux).
- Microchip LAN966x multi-port Gigabit AVB/TSN Ethernet Switch driver
with support for bridging, VLANs and multicast forwarding
(lan966x).
- iwlmei driver for co-operating between Intel's WiFi driver and
Intel's Active Management Technology (AMT) devices.
- mse102x - Vertexcom MSE102x Homeplug GreenPHY chips
- Bluetooth:
- MediaTek MT7921 SDIO devices
- Foxconn MT7922A
- Realtek RTL8852AE
Drivers
-------
- Significantly improve performance in the datapaths of: lan78xx,
ax88179_178a, lantiq_xrx200, bnxt.
- Intel Ethernet NICs:
- igb: support PTP/time PEROUT and EXTTS SDP functions on
82580/i354/i350 adapters
- ixgbevf: new PF -> VF mailbox API which avoids the risk of
mailbox corruption with ESXi
- iavf: support configuration of VLAN features of finer
granularity, stacked tags and filtering
- ice: PTP support for new E822 devices with sub-ns precision
- ice: support firmware activation without reboot
- Mellanox Ethernet NICs (mlx5):
- expose control over IRQ coalescing mode (CQE vs EQE) via ethtool
- support TC forwarding when tunnel encap and decap happen between
two ports of the same NIC
- dynamically size and allow disabling various features to save
resources for running in embedded / SmartNIC scenarios
- Broadcom Ethernet NICs (bnxt):
- use page frag allocator to improve Rx performance
- expose control over IRQ coalescing mode (CQE vs EQE) via ethtool
- Other Ethernet NICs:
- amd-xgbe: add Ryzen 6000 (Yellow Carp) Ethernet support
- Microsoft cloud/virtual NIC (mana):
- add XDP support (PASS, DROP, TX)
- Mellanox Ethernet switches (mlxsw):
- initial support for Spectrum-4 ASICs
- VxLAN with IPv6 underlay
- Marvell Ethernet switches (prestera):
- support flower flow templates
- add basic IP forwarding support
- NXP embedded Ethernet switches (ocelot & felix):
- support Per-Stream Filtering and Policing (PSFP)
- enable cut-through forwarding between ports by default
- support FDMA to improve packet Rx/Tx to CPU
- Other embedded switches:
- hellcreek: improve trapping management (STP and PTP) packets
- qca8k: support link aggregation and port mirroring
- Qualcomm 802.11ax WiFi (ath11k):
- qca6390, wcn6855: enable 802.11 power save mode in station mode
- BSS color change support
- WCN6855 hw2.1 support
- 11d scan offload support
- scan MAC address randomization support
- full monitor mode, only supported on QCN9074
- qca6390/wcn6855: report signal and tx bitrate
- qca6390: rfkill support
- qca6390/wcn6855: regdb.bin support
- Intel WiFi (iwlwifi):
- support SAR GEO Offset Mapping (SGOM) and Time-Aware-SAR (TAS)
in cooperation with the BIOS
- support for Optimized Connectivity Experience (OCE) scan
- support firmware API version 68
- lots of preparatory work for the upcoming Bz device family
- MediaTek WiFi (mt76):
- Specific Absorption Rate (SAR) support
- mt7921: 160 MHz channel support
- RealTek WiFi (rtw88):
- Specific Absorption Rate (SAR) support
- scan offload
- Other WiFi NICs
- ath10k: support fetching (pre-)calibration data from nvmem
- brcmfmac: configure keep-alive packet on suspend
- wcn36xx: beacon filter support"
* tag '5.17-net-next' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2048 commits)
tcp: tcp_send_challenge_ack delete useless param `skb`
net/qla3xxx: Remove useless DMA-32 fallback configuration
rocker: Remove useless DMA-32 fallback configuration
hinic: Remove useless DMA-32 fallback configuration
lan743x: Remove useless DMA-32 fallback configuration
net: enetc: Remove useless DMA-32 fallback configuration
cxgb4vf: Remove useless DMA-32 fallback configuration
cxgb4: Remove useless DMA-32 fallback configuration
cxgb3: Remove useless DMA-32 fallback configuration
bnx2x: Remove useless DMA-32 fallback configuration
et131x: Remove useless DMA-32 fallback configuration
be2net: Remove useless DMA-32 fallback configuration
vmxnet3: Remove useless DMA-32 fallback configuration
bna: Simplify DMA setting
net: alteon: Simplify DMA setting
myri10ge: Simplify DMA setting
qlcnic: Simplify DMA setting
net: allwinner: Fix print format
page_pool: remove spinlock in page_pool_refill_alloc_cache()
amt: fix wrong return type of amt_send_membership_update()
...
Convert 'allowed' in __cpuset_node_allowed() to be boolean since the
return types of node_isset() and __cpuset_node_allowed() are both
boolean.
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
After commit dc26532aed ("cgroup: rstat: punt root-level optimization to
individual controllers"), each rstat on updated_children list has its
->updated_next not NULL.
This means we can remove the check on ->updated_next, if we make sure
the subtree from @root is on list, which could be done by checking
updated_next for root.
tj: Coding style fixes.
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Instead of do while unconditionally, let's put the loop variant in
while.
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
cgroup process migration permission checks are performed at write time as
whether a given operation is allowed or not is dependent on the content of
the write - the PID. This currently uses current's cgroup namespace which is
a potential security weakness as it may allow scenarios where a less
privileged process tricks a more privileged one into writing into a fd that
it created.
This patch makes cgroup remember the cgroup namespace at the time of open
and uses it for migration permission checks instad of current's. Note that
this only applies to cgroup2 as cgroup1 doesn't have namespace support.
This also fixes a use-after-free bug on cgroupns reported in
https://lore.kernel.org/r/00000000000048c15c05d0083397@google.com
Note that backporting this fix also requires the preceding patch.
Reported-by: "Eric W. Biederman" <ebiederm@xmission.com>
Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Reported-by: syzbot+50f5cf33a284ce738b62@syzkaller.appspotmail.com
Link: https://lore.kernel.org/r/00000000000048c15c05d0083397@google.com
Fixes: 5136f6365c ("cgroup: implement "nsdelegate" mount option")
Signed-off-by: Tejun Heo <tj@kernel.org>
of->priv is currently used by each interface file implementation to store
private information. This patch collects the current two private data usages
into struct cgroup_file_ctx which is allocated and freed by the common path.
This allows generic private data which applies to multiple files, which will
be used to in the following patch.
Note that cgroup_procs iterator is now embedded as procs.iter in the new
cgroup_file_ctx so that it doesn't need to be allocated and freed
separately.
v2: union dropped from cgroup_file_ctx and the procs iterator is embedded in
cgroup_file_ctx as suggested by Linus.
v3: Michal pointed out that cgroup1's procs pidlist uses of->priv too.
Converted. Didn't change to embedded allocation as cgroup1 pidlists get
stored for caching.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
cgroup process migration permission checks are performed at write time as
whether a given operation is allowed or not is dependent on the content of
the write - the PID. This currently uses current's credentials which is a
potential security weakness as it may allow scenarios where a less
privileged process tricks a more privileged one into writing into a fd that
it created.
This patch makes both cgroup2 and cgroup1 process migration interfaces to
use the credentials saved at the time of open (file->f_cred) instead of
current's.
Reported-by: "Eric W. Biederman" <ebiederm@xmission.com>
Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org>
Fixes: 187fe84067 ("cgroup: require write perm on common ancestor when moving processes on the default hierarchy")
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
We're about to break the cgroup-defs.h -> bpf-cgroup.h dependency,
make sure those who actually need more than the definition of
struct cgroup_bpf include bpf-cgroup.h explicitly.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/bpf/20211216025538.1649516-3-kuba@kernel.org
If a cset is already on preloaded list, this means we have already setup
this cset properly for migration.
This patch just relocates the root cgrp lookup which isn't used anyway
when the cset is already on the preloaded list.
[tj@kernel.org: rephrase the commit log]
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
In validate_change(), there is a check since v2.6.12 to make sure that
each of the child cpusets must be a subset of a parent cpuset. IOW, it
allows child cpusets to restrict what changes can be made to a parent's
"cpuset.cpus". This actually violates one of the core principles of the
default hierarchy where a cgroup higher up in the hierarchy should be
able to change configuration however it sees fit as deligation breaks
down otherwise.
To address this issue, the check is now removed for the default hierarchy
to free parent cpusets from being restricted by child cpusets. The
check will still apply for legacy hierarchy.
Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
css_alloc() needs the parent css, while cgroup_css() gets current
cgropu's css. So we are getting the wrong css during
cgroup_init_subsys().
Fortunately, cgrp_dfl_root.cgrp's css is not set yet, so the value we
pass to css_alloc() is NULL anyway.
Let's pass NULL directly during init, since we know there is no parent
yet.
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
There is a race between updaters and flushers (flush can possibly miss
the latest update(s)). This is expected as explained in
cgroup_rstat_updated() comment, add also machine readable annotation so
that KCSAN results aren't noisy.
Reported-by: Hao Sun <sunhao.th@gmail.com>
Link: https://lore.kernel.org/r/CACkBjsbPVdkub=e-E-p1WBOLxS515ith-53SFdmFHWV_QMo40w@mail.gmail.com
Suggested-by: Hao Sun <sunhao.th@gmail.com>
Signed-off-by: Michal Koutný <mkoutny@suse.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Merge misc updates from Andrew Morton:
"257 patches.
Subsystems affected by this patch series: scripts, ocfs2, vfs, and
mm (slab-generic, slab, slub, kconfig, dax, kasan, debug, pagecache,
gup, swap, memcg, pagemap, mprotect, mremap, iomap, tracing, vmalloc,
pagealloc, memory-failure, hugetlb, userfaultfd, vmscan, tools,
memblock, oom-kill, hugetlbfs, migration, thp, readahead, nommu, ksm,
vmstat, madvise, memory-hotplug, rmap, zsmalloc, highmem, zram,
cleanups, kfence, and damon)"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (257 commits)
mm/damon: remove return value from before_terminate callback
mm/damon: fix a few spelling mistakes in comments and a pr_debug message
mm/damon: simplify stop mechanism
Docs/admin-guide/mm/pagemap: wordsmith page flags descriptions
Docs/admin-guide/mm/damon/start: simplify the content
Docs/admin-guide/mm/damon/start: fix a wrong link
Docs/admin-guide/mm/damon/start: fix wrong example commands
mm/damon/dbgfs: add adaptive_targets list check before enable monitor_on
mm/damon: remove unnecessary variable initialization
Documentation/admin-guide/mm/damon: add a document for DAMON_RECLAIM
mm/damon: introduce DAMON-based Reclamation (DAMON_RECLAIM)
selftests/damon: support watermarks
mm/damon/dbgfs: support watermarks
mm/damon/schemes: activate schemes based on a watermarks mechanism
tools/selftests/damon: update for regions prioritization of schemes
mm/damon/dbgfs: support prioritization weights
mm/damon/vaddr,paddr: support pageout prioritization
mm/damon/schemes: prioritize regions within the quotas
mm/damon/selftests: support schemes quotas
mm/damon/dbgfs: support quotas of schemes
...
There was a report that starting an Ubuntu in docker while using cpuset
to bind it to movable nodes (a node only has movable zone, like a node
for hotplug or a Persistent Memory node in normal usage) will fail due
to memory allocation failure, and then OOM is involved and many other
innocent processes got killed.
It can be reproduced with command:
$ docker run -it --rm --cpuset-mems 4 ubuntu:latest bash -c "grep Mems_allowed /proc/self/status"
(where node 4 is a movable node)
runc:[2:INIT] invoked oom-killer: gfp_mask=0x500cc2(GFP_HIGHUSER|__GFP_ACCOUNT), order=0, oom_score_adj=0
CPU: 8 PID: 8291 Comm: runc:[2:INIT] Tainted: G W I E 5.8.2-0.g71b519a-default #1 openSUSE Tumbleweed (unreleased)
Hardware name: Dell Inc. PowerEdge R640/0PHYDR, BIOS 2.6.4 04/09/2020
Call Trace:
dump_stack+0x6b/0x88
dump_header+0x4a/0x1e2
oom_kill_process.cold+0xb/0x10
out_of_memory.part.0+0xaf/0x230
out_of_memory+0x3d/0x80
__alloc_pages_slowpath.constprop.0+0x954/0xa20
__alloc_pages_nodemask+0x2d3/0x300
pipe_write+0x322/0x590
new_sync_write+0x196/0x1b0
vfs_write+0x1c3/0x1f0
ksys_write+0xa7/0xe0
do_syscall_64+0x52/0xd0
entry_SYSCALL_64_after_hwframe+0x44/0xa9
Mem-Info:
active_anon:392832 inactive_anon:182 isolated_anon:0
active_file:68130 inactive_file:151527 isolated_file:0
unevictable:2701 dirty:0 writeback:7
slab_reclaimable:51418 slab_unreclaimable:116300
mapped:45825 shmem:735 pagetables:2540 bounce:0
free:159849484 free_pcp:73 free_cma:0
Node 4 active_anon:1448kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB isolated(anon):0kB isolated(file):0kB mapped:0kB dirty:0kB writeback:0kB shmem:0kB shmem_thp: 0kB shmem_pmdmapped: 0kB anon_thp: 0kB writeback_tmp:0kB all_unreclaimable? no
Node 4 Movable free:130021408kB min:9140kB low:139160kB high:269180kB reserved_highatomic:0KB active_anon:1448kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB writepending:0kB present:130023424kB managed:130023424kB mlocked:0kB kernel_stack:0kB pagetables:0kB bounce:0kB free_pcp:292kB local_pcp:84kB free_cma:0kB
lowmem_reserve[]: 0 0 0 0 0
Node 4 Movable: 1*4kB (M) 0*8kB 0*16kB 1*32kB (M) 0*64kB 0*128kB 1*256kB (M) 1*512kB (M) 1*1024kB (M) 0*2048kB 31743*4096kB (M) = 130021156kB
oom-kill:constraint=CONSTRAINT_CPUSET,nodemask=(null),cpuset=docker-9976a269caec812c134fa317f27487ee36e1129beba7278a463dd53e5fb9997b.scope,mems_allowed=4,global_oom,task_memcg=/system.slice/containerd.service,task=containerd,pid=4100,uid=0
Out of memory: Killed process 4100 (containerd) total-vm:4077036kB, anon-rss:51184kB, file-rss:26016kB, shmem-rss:0kB, UID:0 pgtables:676kB oom_score_adj:0
oom_reaper: reaped process 8248 (docker), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB
oom_reaper: reaped process 2054 (node_exporter), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB
oom_reaper: reaped process 1452 (systemd-journal), now anon-rss:0kB, file-rss:8564kB, shmem-rss:4kB
oom_reaper: reaped process 2146 (munin-node), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB
oom_reaper: reaped process 8291 (runc:[2:INIT]), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB
The reason is that in this case, the target cpuset nodes only have
movable zone, while the creation of an OS in docker sometimes needs to
allocate memory in non-movable zones (dma/dma32/normal) like
GFP_HIGHUSER, and the cpuset limit forbids the allocation, then
out-of-memory killing is involved even when normal nodes and movable
nodes both have many free memory.
The OOM killer cannot help to resolve the situation as there is no
usable memory for the request in the cpuset scope. The only reasonable
measure to take is to fail the allocation right away and have the caller
to deal with it.
So add a check for cases like this in the slowpath of allocation, and
bail out early returning NULL for the allocation.
As page allocation is one of the hottest path in kernel, this check will
hurt all users with sane cpuset configuration, add a static branch check
and detect the abnormal config in cpuset memory binding setup so that
the extra check cost in page allocation is not paid by everyone.
[thanks to Micho Hocko and David Rientjes for suggesting not handling
it inside OOM code, adding cpuset check, refining comments]
Link: https://lkml.kernel.org/r/1632481657-68112-1-git-send-email-feng.tang@intel.com
Signed-off-by: Feng Tang <feng.tang@intel.com>
Suggested-by: Michal Hocko <mhocko@suse.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Zefan Li <lizefan.x@bytedance.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull cgroup updates from Tejun Heo:
- The misc controller now reports allocation rejections through
misc.events instead of printking
- cgroup_mutex usage is reduced to improve scalability of some
operations
- vhost helper threads are now assigned to the right cgroup on cgroup2
- Bug fixes
* 'for-5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup: bpf: Move wrapper for __cgroup_bpf_*() to kernel/bpf/cgroup.c
cgroup: Fix rootcg cpu.stat guest double counting
cgroup: no need for cgroup_mutex for /proc/cgroups
cgroup: remove cgroup_mutex from cgroupstats_build
cgroup: reduce dependency on cgroup_mutex
cgroup: cgroup-v1: do not exclude cgrp_dfl_root
cgroup: Make rebind_subsystems() disable v2 controllers all at once
docs/cgroup: add entry for misc.events
misc_cgroup: remove error log to avoid log flood
misc_cgroup: introduce misc.events to count failures
In commit 324bda9e6c5a("bpf: multi program support for cgroup+bpf")
cgroup_bpf_*() called from kernel/bpf/syscall.c, but now they are only
used in kernel/bpf/cgroup.c, so move these function to
kernel/bpf/cgroup.c, like cgroup_bpf_replace().
Signed-off-by: He Fengqing <hefengqing@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
In account_guest_time in kernel/sched/cputime.c guest time is
attributed to both CPUTIME_NICE and CPUTIME_USER in addition to
CPUTIME_GUEST_NICE and CPUTIME_GUEST respectively. Therefore, adding
both to calculate usage results in double counting any guest time at
the rootcg.
Fixes: 936f2a70f2 ("cgroup: add cpu.stat file to root cgroup")
Signed-off-by: Dan Schatzberg <schatzberg.dan@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
On the real systems, the cgroups hierarchies are setup early and just
once by the node controller, so, other than number of cgroups, all
information in /proc/cgroups remain same for the system uptime. Let's
remove the cgroup_mutex usage on reading /proc/cgroups. There is a
chance of inconsistent number of cgroups for co-mounted cgroups while
printing the information from /proc/cgroups but that is not a big
issue. In addition /proc/cgroups is a v1 specific interface, so the
dependency on it should reduce over time.
The main motivation for removing the cgroup_mutex from /proc/cgroups is
to reduce the avenues of its contention. On our fleet, we have observed
buggy application hammering on /proc/cgroups and drastically slowing
down the node controller on the system which have many negative
consequences on other workloads running on the system.
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
The function cgroupstats_build extracts cgroup from the kernfs_node's
priv pointer which is a RCU pointer. So, there is no need to grab
cgroup_mutex. Just get the reference on the cgroup before using and
remove the cgroup_mutex altogether.
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Currently cgroup_get_from_path() and cgroup_get_from_id() grab
cgroup_mutex before traversing the default hierarchy to find the
kernfs_node corresponding to the path/id and then extract the linked
cgroup. Since cgroup_mutex is still held, it is guaranteed that the
cgroup will be alive and the reference can be taken on it.
However similar guarantee can be provided without depending on the
cgroup_mutex and potentially reducing avenues of cgroup_mutex contentions.
The kernfs_node's priv pointer is RCU protected pointer and with just
rcu read lock we can grab the reference on the cgroup without
cgroup_mutex. So, remove cgroup_mutex from them.
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
