Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1310461

Re: [PATCH] memcg: Only free spare array when readers are done

Show all headers | View raw

On Thu, Jan 14, 2016 at 02:33:52PM +0100, Martijn Coenen wrote:
> A spare array holding mem cgroup threshold events is kept around
> to make sure we can always safely deregister an event and have an
> array to store the new set of events in.
> 
> In the scenario where we're going from 1 to 0 registered events, the
> pointer to the primary array containing 1 event is copied to the spare
> slot, and then the spare slot is freed because no events are left.
> However, it is freed before calling synchronize_rcu(), which means
> readers may still be accessing threshold->primary after it is freed.
> 
> Fixed by only freeing after synchronize_rcu().
> 
> Signed-off-by: Martijn Coenen <maco@google.com>

Acked-by: Johannes Weiner <hannes@cmpxchg.org>

Back to linux.kernel | Previous | Next — Previous in thread | Find similar | Unroll thread

Thread

[PATCH] memcg: Only free spare array when readers are done Martijn Coenen <maco@google.com> - 2016-01-14 14:50 +0100
  Re: [PATCH] memcg: Only free spare array when readers are done Michal Hocko <mhocko@kernel.org> - 2016-01-14 15:40 +0100
    Re: [PATCH] memcg: Only free spare array when readers are done Martijn Coenen <maco@google.com> - 2016-01-14 16:40 +0100
  Re: [PATCH] memcg: Only free spare array when readers are done Vladimir Davydov <vdavydov@virtuozzo.com> - 2016-01-15 12:20 +0100
  Re: [PATCH] memcg: Only free spare array when readers are done Johannes Weiner <hannes@cmpxchg.org> - 2016-01-15 22:00 +0100

csiph-web