diff options
| author | Tejun Heo <tj@kernel.org> | 2016-04-21 19:06:48 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-05-04 14:48:49 -0700 |
| commit | d52097476caeb14f4d7e3417dda08220d2813cc4 (patch) | |
| tree | e7fdd0d15a0833977162fe99e2aea17cce43b5a1 /include | |
| parent | a4e25ff31103e7c9084904418cb95596e3e9d9cf (diff) | |
cgroup, cpuset: replace cpuset_post_attach_flush() with cgroup_subsys->post_attach callback
commit 5cf1cacb49aee39c3e02ae87068fc3c6430659b0 upstream.
Since e93ad19d0564 ("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: Tejun Heo <tj@kernel.org>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/cgroup-defs.h | 1 | ||||
| -rw-r--r-- | include/linux/cpuset.h | 6 |
2 files changed, 1 insertions, 6 deletions
diff --git a/include/linux/cgroup-defs.h b/include/linux/cgroup-defs.h index a7c7f74808a4..8da263299754 100644 --- a/include/linux/cgroup-defs.h +++ b/include/linux/cgroup-defs.h @@ -434,6 +434,7 @@ struct cgroup_subsys { int (*can_attach)(struct cgroup_taskset *tset); void (*cancel_attach)(struct cgroup_taskset *tset); void (*attach)(struct cgroup_taskset *tset); + void (*post_attach)(void); int (*can_fork)(struct task_struct *task, void **priv_p); void (*cancel_fork)(struct task_struct *task, void *priv); void (*fork)(struct task_struct *task, void *priv); diff --git a/include/linux/cpuset.h b/include/linux/cpuset.h index fea160ee5803..85a868ccb493 100644 --- a/include/linux/cpuset.h +++ b/include/linux/cpuset.h @@ -137,8 +137,6 @@ static inline void set_mems_allowed(nodemask_t nodemask) task_unlock(current); } -extern void cpuset_post_attach_flush(void); - #else /* !CONFIG_CPUSETS */ static inline bool cpusets_enabled(void) { return false; } @@ -245,10 +243,6 @@ static inline bool read_mems_allowed_retry(unsigned int seq) return false; } -static inline void cpuset_post_attach_flush(void) -{ -} - #endif /* !CONFIG_CPUSETS */ #endif /* _LINUX_CPUSET_H */ |