Messages in this thread | | | Date | Sun, 21 Nov 2010 15:02:28 -0800 | Subject | Re: [PATCH] cgroup: Remove RCU from task->cgroups | From | Colin Cross <> |
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On Sat, Nov 20, 2010 at 6:00 PM, Colin Cross <ccross@android.com> 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 <ccross@android.com> > --- > 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. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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