diff options
| author | Tejun Heo <tj@kernel.org> | 2015-05-13 16:35:16 -0400 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2015-05-26 20:35:00 -0400 |
| commit | 7d7efec368d537226142cbe559f45797f18672f9 (patch) | |
| tree | 8b391dada2b97b66f9fbd4315b397516f13199de /include/linux/cgroup-defs.h | |
| parent | 8ab456ac3697dbd1d3eae5d5817dba941faf89ee (diff) | |
sched, cgroup: reorganize threadgroup locking
threadgroup_change_begin/end() are used to mark the beginning and end
of threadgroup modifying operations to allow code paths which require
a threadgroup to stay stable across blocking operations to synchronize
against those sections using threadgroup_lock/unlock().
It's currently implemented as a general mechanism in sched.h using
per-signal_struct rwsem; however, this never grew non-cgroup use cases
and becomes noop if !CONFIG_CGROUPS. It turns out that cgroups is
gonna be better served with a different sycnrhonization scheme and is
a bit silly to keep cgroups specific details as a general mechanism.
What's general here is identifying the places where threadgroups are
modified. This patch restructures threadgroup locking so that
threadgroup_change_begin/end() become a place where subsystems which
need to sycnhronize against threadgroup changes can hook into.
cgroup_threadgroup_change_begin/end() which operate on the
per-signal_struct rwsem are created and threadgroup_lock/unlock() are
moved to cgroup.c and made static.
This is pure reorganization which doesn't cause any functional
changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Diffstat (limited to 'include/linux/cgroup-defs.h')
| -rw-r--r-- | include/linux/cgroup-defs.h | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/include/linux/cgroup-defs.h b/include/linux/cgroup-defs.h index 55f3120fb952..1b8c93806dbd 100644 --- a/include/linux/cgroup-defs.h +++ b/include/linux/cgroup-defs.h @@ -14,6 +14,7 @@ #include <linux/mutex.h> #include <linux/rcupdate.h> #include <linux/percpu-refcount.h> +#include <linux/percpu-rwsem.h> #include <linux/workqueue.h> #ifdef CONFIG_CGROUPS @@ -460,5 +461,14 @@ struct cgroup_subsys { unsigned int depends_on; }; +void cgroup_threadgroup_change_begin(struct task_struct *tsk); +void cgroup_threadgroup_change_end(struct task_struct *tsk); + +#else /* CONFIG_CGROUPS */ + +static inline void cgroup_threadgroup_change_begin(struct task_struct *tsk) {} +static inline void cgroup_threadgroup_change_end(struct task_struct *tsk) {} + #endif /* CONFIG_CGROUPS */ + #endif /* _LINUX_CGROUP_DEFS_H */ |