On Thu, 1 Nov 2012 14:58:18 -0700 (PDT) David Rientjes <rientjes@xxxxxxxxxx> wrote: > Exiting threads, those with PF_EXITING set, can pagefault and require > memory before they can make forward progress. This happens, for instance, > when a process must fault task->robust_list, a userspace structure, before > detaching its memory. > > These threads also aren't guaranteed to get access to memory reserves > unless oom killed or killed from userspace. The oom killer won't grant > memory reserves if other threads are also exiting other than current and > stalling at the same point. This prevents needlessly killing processes > when others are already exiting. > > Instead of special casing all the possible sitations between PF_EXITING > getting set and a thread detaching its mm where it may allocate memory, > which probably wouldn't get updated when a change is made to the exit > path, the solution is to give all exiting threads access to memory > reserves if they call the oom killer. This allows them to quickly > allocate, detach its mm, and free the memory it represents. Seems very sensible. > Acked-by: Minchan Kim <minchan@xxxxxxxxxx> > Tested-by: Luigi Semenzato <semenzato@xxxxxxxxxx> What did Luigi actually test? Was there some reproducible bad behavior which this patch fixes? -- 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/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>