On Tue, 23 Feb 2010, KAMEZAWA Hiroyuki wrote: > Ouch, I missed to add memcontrol.h to quilt's reflesh set.. > This is updated one. Anyway, I'd like to wait for the next mmotm. > We already have several changes. > I think it would be better to just remove mem_cgroup_out_of_memory() and make it go through out_of_memory() by specifying a non-NULL pointer to a struct mem_cgroup. We don't need the duplication in code that these two functions have and then we can begin to have some consistency with how to deal with panic_on_oom. It would be much better to prefer killing current in pagefault oom conditions, as the final patch in my oom killer rewrite does, if it is killable. If not, we scan the tasklist and find another suitable candidate. If current is bound to a memcg, we pass that to select_bad_process() so that we only kill other tasks from the same cgroup. This allows us to hijack the TIF_MEMDIE bit to detect when there is a parallel pagefault oom killing when the oom killer hasn't necessarily been invoked to kill a system-wide task (it's simply killing current, by default, and giving it access to memory reserves). Then, we can change out_of_memory(), which also now handles memcg oom conditions, to always scan the tasklist first (including for mempolicy and cpuset constrained ooms), check for any candidates that have TIF_MEMDIE, and return ERR_PTR(-1UL) if so. That catches the parallel pagefault oom conditions from needlessly killing memcg tasks. panic_on_oom would only panic after the tasklist scan has completed and returned != ERR_PTR(-1UL), meaning pagefault ooms are exempt from that sysctl. Anyway, do you think it would be possible to rebase on mmotm with my oom killer rewrite patches? They're at http://www.kernel.org/pub/linux/kernel/people/rientjes/oom-killer-rewrite -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>