From f14f3acccbf481063d3625dc5b4b7fc1a0afa2b8 Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Thu, 13 Jan 2011 15:47:29 -0800 Subject: [PATCH] --- yaml --- r: 230825 b: refs/heads/master c: 2919bfd0758257c469abef8c26c3e516bbebb851 h: refs/heads/master i: 230823: fa216e8903f4d1c38c65d67521485be7b9b25e99 v: v3 --- [refs] | 2 +- trunk/mm/ksm.c | 12 ++++++++++++ 2 files changed, 13 insertions(+), 1 deletion(-) diff --git a/[refs] b/[refs] index 0ea4a532319c..c86d833bfffb 100644 --- a/[refs] +++ b/[refs] @@ -1,2 +1,2 @@ --- -refs/heads/master: 73ae31e5986a4c0ee84bfd13ccd9b57a98956f6f +refs/heads/master: 2919bfd0758257c469abef8c26c3e516bbebb851 diff --git a/trunk/mm/ksm.c b/trunk/mm/ksm.c index 33781de0b6bf..c2b2a94f9d67 100644 --- a/trunk/mm/ksm.c +++ b/trunk/mm/ksm.c @@ -1296,6 +1296,18 @@ static struct rmap_item *scan_get_next_rmap_item(struct page **page) slot = ksm_scan.mm_slot; if (slot == &ksm_mm_head) { + /* + * A number of pages can hang around indefinitely on per-cpu + * pagevecs, raised page count preventing write_protect_page + * from merging them. Though it doesn't really matter much, + * it is puzzling to see some stuck in pages_volatile until + * other activity jostles them out, and they also prevented + * LTP's KSM test from succeeding deterministically; so drain + * them here (here rather than on entry to ksm_do_scan(), + * so we don't IPI too often when pages_to_scan is set low). + */ + lru_add_drain_all(); + root_unstable_tree = RB_ROOT; spin_lock(&ksm_mmlist_lock);