On 03/05/2011 06:20 PM, Minchan Kim wrote: > On Sat, Mar 05, 2011 at 02:44:16PM +0300, Andrey Vagin wrote: >> Check zone->all_unreclaimable in all_unreclaimable(), otherwise the >> kernel may hang up, because shrink_zones() will do nothing, but >> all_unreclaimable() will say, that zone has reclaimable pages. >> >> do_try_to_free_pages() >> shrink_zones() >> for_each_zone >> if (zone->all_unreclaimable) >> continue >> if !all_unreclaimable(zonelist, sc) >> return 1 >> >> __alloc_pages_slowpath() >> retry: >> did_some_progress = do_try_to_free_pages(page) >> ... >> if (!page&& did_some_progress) >> retry; >> >> Signed-off-by: Andrey Vagin >> --- >> mm/vmscan.c | 2 ++ >> 1 files changed, 2 insertions(+), 0 deletions(-) >> >> diff --git a/mm/vmscan.c b/mm/vmscan.c >> index 6771ea7..1c056f7 100644 >> --- a/mm/vmscan.c >> +++ b/mm/vmscan.c >> @@ -2002,6 +2002,8 @@ static bool all_unreclaimable(struct zonelist *zonelist, >> >> for_each_zone_zonelist_nodemask(zone, z, zonelist, >> gfp_zone(sc->gfp_mask), sc->nodemask) { >> + if (zone->all_unreclaimable) >> + continue; >> if (!populated_zone(zone)) >> continue; >> if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL)) > > zone_reclaimable checks it. Isn't it enough? I sent one more patch [PATCH] mm: skip zombie in OOM-killer. This two patches are enough. > Does the hang up really happen or see it by code review? Yes. You can reproduce it for help the attached python program. It's not very clever:) It make the following actions in loop: 1. fork 2. mmap 3. touch memory 4. read memory 5. munmmap >> -- >> 1.7.1 >> >> -- >> To unsubscribe, send a message with 'unsubscribe linux-mm' in >> the body to majordomo@kvack.org. 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: email@kvack.org