On Thu, 17 Mar 2011 22:17:58 -0700 Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > On Fri, 18 Mar 2011 13:35:34 +0900 KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> wrote: > > > On Thu, 17 Mar 2011 16:53:19 -0700 > > Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > > > > > > > > Was it deliberate that mem_cgroup_out_of_memory() ignores the oom > > > notifier callbacks? > > > > > > > I'm not sure for what purpose notifier chain for oom exists. > > At a loock, it's for s390/powerpc Collaborative Memory Manager.. ? > > commit 8bc719d3cab8414938f9ea6e33b58d8810d18068 > Author: Martin Schwidefsky <schwidefsky@xxxxxxxxxx> > AuthorDate: Mon Sep 25 23:31:20 2006 -0700 > Commit: Linus Torvalds <torvalds@xxxxxxxxxxx> > CommitDate: Tue Sep 26 08:48:47 2006 -0700 > > [PATCH] out of memory notifier > > Add a notifer chain to the out of memory killer. If one of the registered > callbacks could release some memory, do not kill the process but return and > retry the allocation that forced the oom killer to run. > > The purpose of the notifier is to add a safety net in the presence of > memory ballooners. If the resource manager inflated the balloon to a size > where memory allocations can not be satisfied anymore, it is better to > deflate the balloon a bit instead of killing processes. > > The implementation for the s390 ballooner is included. > > > About memcg, notifier to userland already exists and I though I don't > > need to call CMM callbacks (for now, there is no user with memcg, I guess.) > > Seems to me that the callback should be performed. > Hmm, (for now) memory cgroup just handles user's memory, so any kernel callback cannot do anything..other than dropping file cache if some module pins it. > Or, perhaps, migrate it over to use the shrinker stuff, along with > suitable handling of the scanning priority. > Ah, yes. callback at oom is too late, I think. Thanks, -Kame -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>