On Sat, Nov 20, 2010 at 6:00 PM, Colin Cross <[email protected]> wrote: > The synchronize_rcu call in cgroup_attach_task can be very > expensive. All fastpath accesses to task->cgroups already > use task_lock() or cgroup_lock() to protect against updates, > and only the CGROUP_DEBUG files have RCU read-side critical > sections. > > This patch replaces rcu_read_lock() with task_lock(current) > around the debug file acceses to current->cgroups and removes > the synchronize_rcu call in cgroup_attach_task. > > Signed-off-by: Colin Cross <[email protected]> > --- > kernel/cgroup.c | 22 ++++++++-------------- > 1 files changed, 8 insertions(+), 14 deletions(-) >
This patch isn't correct, there's an rcu_dereference I missed inside task_group(), and that's the important one. _______________________________________________ Containers mailing list [email protected] https://lists.linux-foundation.org/mailman/listinfo/containers _______________________________________________ Devel mailing list [email protected] https://openvz.org/mailman/listinfo/devel
