On Fri, 9 Nov 2007 07:13:22 +0000 (GMT) Hugh Dickins <hugh@xxxxxxxxxxx> wrote: > mem_cgroup_charge_common shows a tendency to OOM without good reason, > when a memhog goes well beyond its rss limit but with plenty of swap > available. Seen on x86 but not on PowerPC; seen when the next patch > omits swapcache from memcgroup, but we presume it can happen without. > > mem_cgroup_isolate_pages is not quite satisfying reclaim's criteria > for OOM avoidance. Already it has to scan beyond the nr_to_scan limit > when it finds a !LRU page or an active page when handling inactive or > an inactive page when handling active. It needs to do exactly the same > when it finds a page from the wrong zone (the x86 tests had two zones, > the PowerPC tests had only one). > > Don't increment scan and then decrement it in these cases, just move > the incrementation down. Fix recent off-by-one when checking against > nr_to_scan. Cut out "Check if the meta page went away from under us", > presumably left over from early debugging: no amount of such checks > could save us if this list really were being updated without locking. > > This change does make the unlimited scan while holding two spinlocks > even worse - bad for latency and bad for containment; but that's a > separate issue which is better left to be fixed a little later. > Okay, I agree with this logic for scan. I'll consider some kind of optimization for avoiding all list scan because of a zone's page is not included in cgroup's lru. Maybe counting the number of active/inactive per zone (or per node) will be first help. Thanks, -Kame _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/containers
