On Wed 18-04-12 23:34:46, Hugh Dickins wrote: > My 9ce70c0240d0 "memcg: fix deadlock by inverting lrucare nesting" put a > nasty little bug into v3.3's version of mem_cgroup_replace_page_cache(), > sometimes used for FUSE. Replacing __mem_cgroup_commit_charge_lrucare() > by __mem_cgroup_commit_charge(), I used the "pc" pointer set up earlier: > but it's for oldpage, and needs now to be for newpage. Once oldpage was > freed, its PageCgroupUsed bit (cleared above but set again here) caused > "Bad page state" messages - and perhaps worse, being missed from newpage. > (I didn't find this by using FUSE, but in reusing the function for tmpfs.) > > Signed-off-by: Hugh Dickins <hughd@xxxxxxxxxx> Acked-by: Michal Hocko <mhocko@xxxxxxx> Thanks > Cc: stable@xxxxxxxxxxxxxxx [v3.3 only] > --- > > mm/memcontrol.c | 1 + > 1 file changed, 1 insertion(+) > > --- 3.4-rc3/mm/memcontrol.c 2012-04-15 20:47:37.151777506 -0700 > +++ linux/mm/memcontrol.c 2012-04-18 22:29:18.490639511 -0700 > @@ -3392,6 +3392,7 @@ void mem_cgroup_replace_page_cache(struc > * the newpage may be on LRU(or pagevec for LRU) already. We lock > * LRU while we overwrite pc->mem_cgroup. > */ > + pc = lookup_page_cgroup(newpage); > __mem_cgroup_commit_charge(memcg, newpage, 1, pc, type, true); > } > > > -- > 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/ . > Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ > Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a> -- Michal Hocko SUSE Labs SUSE LINUX s.r.o. Lihovarska 1060/12 190 00 Praha 9 Czech Republic -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>