Hello, Linus.
Two fixes for cgroup.
* There still was a hole in enforcing cpuset rules, fixed by Li.
* Recent switch to global percpu_rwseom for threadgroup locking
revealed a couple issues in how percpu_rwsem is implemented and used
by cgroup. Balbir found that the read locking section was too wide
unnecessarily including operations which can often depend on IOs.
With percpu_rwsem updates (coming through a different tree) and
reduction of read locking section, all the reported locking latency
issues, including the android one, are resolved.
It looks like we can keep global percpu_rwsem locking for now. If
there actually are cases which can't be resolved, we can go back to
more complex per-signal_struct locking.
Thanks.
The following changes since commit 29b4817d4018df78086157ea3a55c1d9424a7cfc:
Linux 4.8-rc1 (2016-08-07 18:18:00 -0700)
are available in the git repository at:
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup.git for-4.8-fixes
for you to fetch changes up to 568ac888215c7fb2fabe8ea739b00ec3c1f5d440:
cgroup: reduce read locked section of cgroup_threadgroup_rwsem during fork
(2016-08-17 09:54:52 -0400)
----------------------------------------------------------------
Balbir Singh (1):
cgroup: reduce read locked section of cgroup_threadgroup_rwsem during fork
Zefan Li (1):
cpuset: make sure new tasks conform to the current config of the cpuset
kernel/cpuset.c | 15 +++++++++++++++
kernel/fork.c | 4 ++--
2 files changed, 17 insertions(+), 2 deletions(-)
--
tejun
