On Thu, Jul 14, 2011 at 8:59 PM, Michal Hocko <mhocko@xxxxxxx> wrote: > memcg_oom_mutex is used to protect memcg OOM path and eventfd interface > for oom_control. None of the critical sections which it protects sleep > (eventfd_signal works from atomic context and the rest are simple linked > list resp. oom_lock atomic operations). > Mutex is also too heavy weight for those code paths because it triggers > a lot of scheduling. It also makes makes convoying effects more visible > when we have a big number of oom killing because we take the lock > mutliple times during mem_cgroup_handle_oom so we have multiple places > where many processes can sleep. > > Signed-off-by: Michal Hocko <mhocko@xxxxxxx> Quick question: How long do we expect this lock to be taken? What happens under oom? Any tests? Numbers? Balbir Singh -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>