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  1. 09 2月, 2023 1 次提交
  3. 01 12月, 2022 1 次提交
  5. 23 11月, 2022 1 次提交
    • L
      cgroup: support cgroup writeback on cgroupv1 · 644547a9
      由 Lu Jialin 提交于 
      hulkl inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5ZG61

-------------------------------

In cgroupv1, cgroup writeback is not supproted for two problems:
1) Blkcg_css and memcg_css are mounted on different cgroup trees.
   Therefore, blkcg_css cannot be found according to a certain memcg_css.
2) Buffer I/O is worked by kthread, which is in the root_blkcg.
   Therefore, blkcg cannot limit wbps and wiops of buffer I/O.

We solve the two problems to support cgroup writeback on cgroupv1.
1) A memcg is attached to the blkcg_root css when the memcg was created.
2) We add a member "wb_blkio_ino" in mem_cgroup_legacy_files.
   User can attach a memcg to a cerntain blkcg through echo the file
   inode of the blkcg into the wb_blkio of the memcg.
3) inode_cgwb_enabled() return true when memcg and io are both mounted
   on cgroupv2 or both on cgroupv1.
4) Buffer I/O can find a blkcg according to its memcg.

Thus, a memcg can find a certain blkcg, and cgroup writeback can be
supported on cgroupv1.
Signed-off-by: NLu Jialin <lujialin4@huawei.com>
      644547a9
  7. 15 11月, 2022 1 次提交
  9. 07 9月, 2022 2 次提交
  11. 09 8月, 2022 4 次提交
  13. 06 7月, 2022 1 次提交
  15. 22 6月, 2022 1 次提交
    • T
      mm: memcontrol: add the flag_stat file · 5cda4079
      由 tatataeki 提交于 
      hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I4MC3F
CVE: NA

----------------------------------

Multiple operations on cgroups in cgroup v1 are related to the status
of the cgroup. The status of the current cgroup can be displayed in
cgroupv2, but it cannot be displayed in cgroup v1, so the
cgroup.flag_stat member is added in memory cgroup to display the
status of the current cgroup and sub-cgroups.

Testing result:
List the status of user.slice
[root@test user.slice]#cat memory.flag_stat
NO_REF 0
ONLINE 1
RELEASED 0
VISIBLE 1
DYING 0
CHILD_NO_REF 0
CHILD_ONLINE 1
CHILD_RELEASED 0
CHILD_VISIBLE 1
CHILD_DYING 0

Create a new cgroup in user.slice
[root@test user.slice]#mkdir user-test

List the current status of user.slice after operation above
[root@test user.slice]#cat memory.flag_stat
NO_REF 0
ONLINE 1
RELEASED 0
VISIBLE 1
DYING 0
CHILD_NO_REF 0
CHILD_ONLINE 2
CHILD_RELEASED 0
CHILD_VISIBLE 2
CHILD_DYING 0
Signed-off-by: Ntatataeki <shengzeyu19_98@163.com>
Reviewed-by: NKefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: NXiu Jianfeng <xiujianfeng@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
      5cda4079
  17. 07 6月, 2022 2 次提交
    • C
      memcg: introduce per-memcg reclaim interface for cgroup v1 · f698ccf8
      由 Chen Wandun 提交于 
      hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I545DF
CVE: NA

--------------------------------

introduce per-memcg reclaim interface for cgroup v1, and
disable memory reclaim for root memcg.
Signed-off-by: NChen Wandun <chenwandun@huawei.com>
Reviewed-by: NKefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
      f698ccf8
    • S
      memcg: introduce per-memcg reclaim interface · 50b7afef
      由 Shakeel Butt 提交于 
      mainline inclusion
from mainline-v5.19-rc1
commit 94968384
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I545DF
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=94968384dde15d48263bfc59d280cd71b1259d8c

--------------------------------

This patch series adds a memory.reclaim proactive reclaim interface.
The rationale behind the interface and how it works are in the first
patch.

This patch (of 4):

Introduce a memcg interface to trigger memory reclaim on a memory cgroup.

Use case: Proactive Reclaim
---------------------------

A userspace proactive reclaimer can continuously probe the memcg to
reclaim a small amount of memory.  This gives more accurate and up-to-date
workingset estimation as the LRUs are continuously sorted and can
potentially provide more deterministic memory overcommit behavior.  The
memory overcommit controller can provide more proactive response to the
changing behavior of the running applications instead of being reactive.

A userspace reclaimer's purpose in this case is not a complete replacement
for kswapd or direct reclaim, it is to proactively identify memory savings
opportunities and reclaim some amount of cold pages set by the policy to
free up the memory for more demanding jobs or scheduling new jobs.

A user space proactive reclaimer is used in Google data centers.
Additionally, Meta's TMO paper recently referenced a very similar
interface used for user space proactive reclaim:
https://dl.acm.org/doi/pdf/10.1145/3503222.3507731

Benefits of a user space reclaimer:
-----------------------------------

1) More flexible on who should be charged for the cpu of the memory
   reclaim.  For proactive reclaim, it makes more sense to be centralized.

2) More flexible on dedicating the resources (like cpu).  The memory
   overcommit controller can balance the cost between the cpu usage and
   the memory reclaimed.

3) Provides a way to the applications to keep their LRUs sorted, so,
   under memory pressure better reclaim candidates are selected.  This
   also gives more accurate and uptodate notion of working set for an
   application.

Why memory.high is not enough?
------------------------------

- memory.high can be used to trigger reclaim in a memcg and can
  potentially be used for proactive reclaim.  However there is a big
  downside in using memory.high.  It can potentially introduce high
  reclaim stalls in the target application as the allocations from the
  processes or the threads of the application can hit the temporary
  memory.high limit.

- Userspace proactive reclaimers usually use feedback loops to decide
  how much memory to proactively reclaim from a workload.  The metrics
  used for this are usually either refaults or PSI, and these metrics will
  become messy if the application gets throttled by hitting the high
  limit.

- memory.high is a stateful interface, if the userspace proactive
  reclaimer crashes for any reason while triggering reclaim it can leave
  the application in a bad state.

- If a workload is rapidly expanding, setting memory.high to proactively
  reclaim memory can result in actually reclaiming more memory than
  intended.

The benefits of such interface and shortcomings of existing interface were
further discussed in this RFC thread:
https://lore.kernel.org/linux-mm/5df21376-7dd1-bf81-8414-32a73cea45dd@google.com/

Interface:
----------

Introducing a very simple memcg interface 'echo 10M > memory.reclaim' to
trigger reclaim in the target memory cgroup.

The interface is introduced as a nested-keyed file to allow for future
optional arguments to be easily added to configure the behavior of
reclaim.

Possible Extensions:
--------------------

- This interface can be extended with an additional parameter or flags
  to allow specifying one or more types of memory to reclaim from (e.g.
  file, anon, ..).

- The interface can also be extended with a node mask to reclaim from
  specific nodes. This has use cases for reclaim-based demotion in memory
  tiering systens.

- A similar per-node interface can also be added to support proactive
  reclaim and reclaim-based demotion in systems without memcg.

- Add a timeout parameter to make it easier for user space to call the
  interface without worrying about being blocked for an undefined amount
  of time.

For now, let's keep things simple by adding the basic functionality.

[yosryahmed@google.com: worked on versions v2 onwards, refreshed to
current master, updated commit message based on recent
discussions and use cases]
Link: https://lkml.kernel.org/r/20220425190040.2475377-1-yosryahmed@google.com
Link: https://lkml.kernel.org/r/20220425190040.2475377-2-yosryahmed@google.comSigned-off-by: NShakeel Butt <shakeelb@google.com>
Co-developed-by: NYosry Ahmed <yosryahmed@google.com>
Signed-off-by: NYosry Ahmed <yosryahmed@google.com>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Acked-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NWei Xu <weixugc@google.com>
Acked-by: NRoman Gushchin <roman.gushchin@linux.dev>
Acked-by: NDavid Rientjes <rientjes@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Zefan Li <lizefan.x@bytedance.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Chen Wandun <chenwandun@huawei.com>
Cc: Vaibhav Jain <vaibhav@linux.ibm.com>
Cc: "Michal Koutn" <mkoutny@suse.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NChen Wandun <chenwandun@huawei.com>
Reviewed-by: NKefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
      50b7afef
  19. 23 5月, 2022 1 次提交
    • R
      mm: memcg: synchronize objcg lists with a dedicated spinlock · 9ba3dc33
      由 Roman Gushchin 提交于 
      stable inclusion
from stable-v5.10.102
commit 8c8385972ea96adeb9b678c9390beaa4d94c4aae
bugzilla: https://gitee.com/openeuler/kernel/issues/I567K6

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=8c8385972ea96adeb9b678c9390beaa4d94c4aae

--------------------------------

commit 0764db9b upstream.

Alexander reported a circular lock dependency revealed by the mmap1 ltp
test:

  LOCKDEP_CIRCULAR (suite: ltp, case: mtest06 (mmap1))
          WARNING: possible circular locking dependency detected
          5.17.0-20220113.rc0.git0.f2211f194038.300.fc35.s390x+debug #1 Not tainted
          ------------------------------------------------------
          mmap1/202299 is trying to acquire lock:
          00000001892c0188 (css_set_lock){..-.}-{2:2}, at: obj_cgroup_release+0x4a/0xe0
          but task is already holding lock:
          00000000ca3b3818 (&sighand->siglock){-.-.}-{2:2}, at: force_sig_info_to_task+0x38/0x180
          which lock already depends on the new lock.
          the existing dependency chain (in reverse order) is:
          -> #1 (&sighand->siglock){-.-.}-{2:2}:
                 __lock_acquire+0x604/0xbd8
                 lock_acquire.part.0+0xe2/0x238
                 lock_acquire+0xb0/0x200
                 _raw_spin_lock_irqsave+0x6a/0xd8
                 __lock_task_sighand+0x90/0x190
                 cgroup_freeze_task+0x2e/0x90
                 cgroup_migrate_execute+0x11c/0x608
                 cgroup_update_dfl_csses+0x246/0x270
                 cgroup_subtree_control_write+0x238/0x518
                 kernfs_fop_write_iter+0x13e/0x1e0
                 new_sync_write+0x100/0x190
                 vfs_write+0x22c/0x2d8
                 ksys_write+0x6c/0xf8
                 __do_syscall+0x1da/0x208
                 system_call+0x82/0xb0
          -> #0 (css_set_lock){..-.}-{2:2}:
                 check_prev_add+0xe0/0xed8
                 validate_chain+0x736/0xb20
                 __lock_acquire+0x604/0xbd8
                 lock_acquire.part.0+0xe2/0x238
                 lock_acquire+0xb0/0x200
                 _raw_spin_lock_irqsave+0x6a/0xd8
                 obj_cgroup_release+0x4a/0xe0
                 percpu_ref_put_many.constprop.0+0x150/0x168
                 drain_obj_stock+0x94/0xe8
                 refill_obj_stock+0x94/0x278
                 obj_cgroup_charge+0x164/0x1d8
                 kmem_cache_alloc+0xac/0x528
                 __sigqueue_alloc+0x150/0x308
                 __send_signal+0x260/0x550
                 send_signal+0x7e/0x348
                 force_sig_info_to_task+0x104/0x180
                 force_sig_fault+0x48/0x58
                 __do_pgm_check+0x120/0x1f0
                 pgm_check_handler+0x11e/0x180
          other info that might help us debug this:
           Possible unsafe locking scenario:
                 CPU0                    CPU1
                 ----                    ----
            lock(&sighand->siglock);
                                         lock(css_set_lock);
                                         lock(&sighand->siglock);
            lock(css_set_lock);
           *** DEADLOCK ***
          2 locks held by mmap1/202299:
           #0: 00000000ca3b3818 (&sighand->siglock){-.-.}-{2:2}, at: force_sig_info_to_task+0x38/0x180
           #1: 00000001892ad560 (rcu_read_lock){....}-{1:2}, at: percpu_ref_put_many.constprop.0+0x0/0x168
          stack backtrace:
          CPU: 15 PID: 202299 Comm: mmap1 Not tainted 5.17.0-20220113.rc0.git0.f2211f194038.300.fc35.s390x+debug #1
          Hardware name: IBM 3906 M04 704 (LPAR)
          Call Trace:
            dump_stack_lvl+0x76/0x98
            check_noncircular+0x136/0x158
            check_prev_add+0xe0/0xed8
            validate_chain+0x736/0xb20
            __lock_acquire+0x604/0xbd8
            lock_acquire.part.0+0xe2/0x238
            lock_acquire+0xb0/0x200
            _raw_spin_lock_irqsave+0x6a/0xd8
            obj_cgroup_release+0x4a/0xe0
            percpu_ref_put_many.constprop.0+0x150/0x168
            drain_obj_stock+0x94/0xe8
            refill_obj_stock+0x94/0x278
            obj_cgroup_charge+0x164/0x1d8
            kmem_cache_alloc+0xac/0x528
            __sigqueue_alloc+0x150/0x308
            __send_signal+0x260/0x550
            send_signal+0x7e/0x348
            force_sig_info_to_task+0x104/0x180
            force_sig_fault+0x48/0x58
            __do_pgm_check+0x120/0x1f0
            pgm_check_handler+0x11e/0x180
          INFO: lockdep is turned off.

In this example a slab allocation from __send_signal() caused a
refilling and draining of a percpu objcg stock, resulted in a releasing
of another non-related objcg.  Objcg release path requires taking the
css_set_lock, which is used to synchronize objcg lists.

This can create a circular dependency with the sighandler lock, which is
taken with the locked css_set_lock by the freezer code (to freeze a
task).

In general it seems that using css_set_lock to synchronize objcg lists
makes any slab allocations and deallocation with the locked css_set_lock
and any intervened locks risky.

To fix the problem and make the code more robust let's stop using
css_set_lock to synchronize objcg lists and use a new dedicated spinlock
instead.

Link: https://lkml.kernel.org/r/Yfm1IHmoGdyUR81T@carbon.dhcp.thefacebook.com
Fixes: bf4f0599 ("mm: memcg/slab: obj_cgroup API")
Signed-off-by: NRoman Gushchin <guro@fb.com>
Reported-by: NAlexander Egorenkov <egorenar@linux.ibm.com>
Tested-by: NAlexander Egorenkov <egorenar@linux.ibm.com>
Reviewed-by: NWaiman Long <longman@redhat.com>
Acked-by: NTejun Heo <tj@kernel.org>
Reviewed-by: NShakeel Butt <shakeelb@google.com>
Reviewed-by: NJeremy Linton <jeremy.linton@arm.com>
Tested-by: NJeremy Linton <jeremy.linton@arm.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NYu Liao <liaoyu15@huawei.com>
Reviewed-by: NWei Li <liwei391@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
      9ba3dc33
  21. 07 4月, 2022 2 次提交
  23. 20 3月, 2022 1 次提交
  25. 19 1月, 2022 5 次提交
  27. 07 1月, 2022 4 次提交
  29. 30 12月, 2021 1 次提交
  31. 06 12月, 2021 1 次提交
    • V
      memcg: prohibit unconditional exceeding the limit of dying tasks · 8937d4d7
      由 Vasily Averin 提交于 
      stable inclusion
from stable-5.10.80
commit 74293225f50391620aaef3507ebd6fd17e0003e1
bugzilla: 185821 https://gitee.com/openeuler/kernel/issues/I4L7CG

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=74293225f50391620aaef3507ebd6fd17e0003e1

--------------------------------

commit a4ebf1b6 upstream.

Memory cgroup charging allows killed or exiting tasks to exceed the hard
limit.  It is assumed that the amount of the memory charged by those
tasks is bound and most of the memory will get released while the task
is exiting.  This is resembling a heuristic for the global OOM situation
when tasks get access to memory reserves.  There is no global memory
shortage at the memcg level so the memcg heuristic is more relieved.

The above assumption is overly optimistic though.  E.g.  vmalloc can
scale to really large requests and the heuristic would allow that.  We
used to have an early break in the vmalloc allocator for killed tasks
but this has been reverted by commit b8c8a338 ("Revert "vmalloc:
back off when the current task is killed"").  There are likely other
similar code paths which do not check for fatal signals in an
allocation&charge loop.  Also there are some kernel objects charged to a
memcg which are not bound to a process life time.

It has been observed that it is not really hard to trigger these
bypasses and cause global OOM situation.

One potential way to address these runaways would be to limit the amount
of excess (similar to the global OOM with limited oom reserves).  This
is certainly possible but it is not really clear how much of an excess
is desirable and still protects from global OOMs as that would have to
consider the overall memcg configuration.

This patch is addressing the problem by removing the heuristic
altogether.  Bypass is only allowed for requests which either cannot
fail or where the failure is not desirable while excess should be still
limited (e.g.  atomic requests).  Implementation wise a killed or dying
task fails to charge if it has passed the OOM killer stage.  That should
give all forms of reclaim chance to restore the limit before the failure
(ENOMEM) and tell the caller to back off.

In addition, this patch renames should_force_charge() helper to
task_is_dying() because now its use is not associated witch forced
charging.

This patch depends on pagefault_out_of_memory() to not trigger
out_of_memory(), because then a memcg failure can unwind to VM_FAULT_OOM
and cause a global OOM killer.

Link: https://lkml.kernel.org/r/8f5cebbb-06da-4902-91f0-6566fc4b4203@virtuozzo.comSigned-off-by: NVasily Averin <vvs@virtuozzo.com>
Suggested-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Uladzislau Rezki <urezki@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Reviewed-by: NWeilong Chen <chenweilong@huawei.com>
Acked-by: NWeilong Chen <chenweilong@huawei.com>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
      8937d4d7
  33. 30 11月, 2021 11 次提交