On Wed, 28 Dec 2011 16:20:25 -0800 (PST) Hugh Dickins <hughd@xxxxxxxxxx> wrote: > This patch started off as a cleanup: __split_huge_page_refcounts() has to > cope with two scenarios, when the hugepage being split is already on LRU, > and when it is not; but why does it have to split that accounting across > three different sites? Consolidate it in lru_add_page_tail(), handling > evictable and unevictable alike, and use standard add_page_to_lru_list() > when accounting is needed (when the head is not yet on LRU). > > But a recent regression in -next, I guess the removal of PageCgroupAcctLRU > test from mem_cgroup_split_huge_fixup(), makes this now a necessary fix: > under load, the MEM_CGROUP_ZSTAT count was wrapping to a huge number, > messing up reclaim calculations and causing a freeze at rmdir of cgroup. > > Add a VM_BUG_ON to mem_cgroup_lru_del_list() when we're about to wrap > that count - this has not been the only such incident. Document that > lru_add_page_tail() is for Transparent HugePages by #ifdef around it. > > Signed-off-by: Hugh Dickins <hughd@xxxxxxxxxx> seems saner. Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> Thank you. -- 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>