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  1. 02 May, 2016 1 commit
    • Serge Hallyn's avatar
      kernfs_path_from_node_locked: don't overwrite nlen · e99ed4de
      Serge Hallyn authored 
      We've calculated @len to be the bytes we need for '/..' entries from
@kn_from to the common ancestor, and calculated @nlen to be the extra
bytes we need to get from the common ancestor to @kn_to.  We use them
as such at the end.  But in the loop copying the actual entries, we
overwrite @nlen.  Use a temporary variable for that instead.

Without this, the return length, when the buffer is large enough, is
wrong.  (When the buffer is NULL or too small, the returned value is
correct. The buffer contents are also correct.)

Interestingly, no callers of this function are affected by this as of
yet.  However the upcoming cgroup_show_path() will be.
Signed-off-by: default avatarSerge Hallyn <serge.hallyn@ubuntu.com>
      e99ed4de
  3. 25 Apr, 2016 3 commits
    • Tejun Heo's avatar
      memcg: relocate charge moving from ->attach to ->post_attach · 264a0ae1
      Tejun Heo authored 
      Hello,

So, this ended up a lot simpler than I originally expected.  I tested
it lightly and it seems to work fine.  Petr, can you please test these
two patches w/o the lru drain drop patch and see whether the problem
is gone?

Thanks.
------ 8< ------
If charge moving is used, memcg performs relabeling of the affected
pages from its ->attach callback which is called under both
cgroup_threadgroup_rwsem and thus can't create new kthreads.  This is
fragile as various operations may depend on workqueues making forward
progress which relies on the ability to create new kthreads.

There's no reason to perform charge moving from ->attach which is deep
in the task migration path.  Move it to ->post_attach which is called
after the actual migration is finished and cgroup_threadgroup_rwsem is
dropped.

* move_charge_struct->mm is added and ->can_attach is now responsible
  for pinning and recording the target mm.  mem_cgroup_clear_mc() is
  updated accordingly.  This also simplifies mem_cgroup_move_task().

* mem_cgroup_move_task() is now called from ->post_attach instead of
  ->attach.
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: default avatarMichal Hocko <mhocko@kernel.org>
Debugged-and-tested-by: default avatarPetr Mladek <pmladek@suse.com>
Reported-by: default avatarCyril Hrubis <chrubis@suse.cz>
Reported-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
Fixes: 1ed13287 ("sched, cgroup: replace signal_struct->group_rwsem with a global percpu_rwsem")
Cc: <stable@vger.kernel.org> # 4.4+
      264a0ae1
    • Tejun Heo's avatar
      cgroup, cpuset: replace cpuset_post_attach_flush() with cgroup_subsys->post_attach callback · 5cf1cacb
      Tejun Heo authored 
      Since e93ad19d ("cpuset: make mm migration asynchronous"), cpuset
kicks off asynchronous NUMA node migration if necessary during task
migration and flushes it from cpuset_post_attach_flush() which is
called at the end of __cgroup_procs_write().  This is to avoid
performing migration with cgroup_threadgroup_rwsem write-locked which
can lead to deadlock through dependency on kworker creation.

memcg has a similar issue with charge moving, so let's convert it to
an official callback rather than the current one-off cpuset specific
function.  This patch adds cgroup_subsys->post_attach callback and
makes cpuset register cpuset_post_attach_flush() as its ->post_attach.

The conversion is mostly one-to-one except that the new callback is
called under cgroup_mutex.  This is to guarantee that no other
migration operations are started before ->post_attach callbacks are
finished.  cgroup_mutex is one of the outermost mutex in the system
and has never been and shouldn't be a problem.  We can add specialized
synchronization around __cgroup_procs_write() but I don't think
there's any noticeable benefit.
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: <stable@vger.kernel.org> # 4.4+ prerequisite for the next patch
      5cf1cacb
    • Linus Torvalds's avatar
      Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 · bcc981e9
      Linus Torvalds authored 
      Pull crypto fixes from Herbert Xu:
 "This fixes a couple of regressions in the talitos driver that were
  introduced back in 4.3.

  The first bug causes a crash when the driver's AEAD functionality is
  used while the second bug prevents its AEAD feature from working once
  you get past the first bug"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: talitos - fix AEAD tcrypt tests
  crypto: talitos - fix crash in talitos_cra_init()
      bcc981e9
  5. 24 Apr, 2016 2 commits
  7. 23 Apr, 2016 10 commits
  9. 22 Apr, 2016 24 commits
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