From d6d76c6649ec10061810780c0d2398a0232ed1d3 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Tue, 10 Sep 2013 11:43:37 +0800 Subject: [PATCH] slub: Fix calculation of cpu slabs commit 8afb1474db4701d1ab80cd8251137a3260e6913e upstream. /sys/kernel/slab/:t-0000048 # cat cpu_slabs 231 N0=16 N1=215 /sys/kernel/slab/:t-0000048 # cat slabs 145 N0=36 N1=109 See, the number of slabs is smaller than that of cpu slabs. The bug was introduced by commit 49e2258586b423684f03c278149ab46d8f8b6700 ("slub: per cpu cache for partial pages"). We should use page->pages instead of page->pobjects when calculating the number of cpu partial slabs. This also fixes the mapping of slabs and nodes. As there's no variable storing the number of total/active objects in cpu partial slabs, and we don't have user interfaces requiring those statistics, I just add WARN_ON for those cases. Acked-by: Christoph Lameter Reviewed-by: Wanpeng Li Signed-off-by: Li Zefan Signed-off-by: Pekka Enberg Signed-off-by: Greg Kroah-Hartman --- mm/slub.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/mm/slub.c b/mm/slub.c index c34bd44..deaed7b 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -4285,7 +4285,13 @@ static ssize_t show_slab_objects(struct kmem_cache *s, page = ACCESS_ONCE(c->partial); if (page) { - x = page->pobjects; + node = page_to_nid(page); + if (flags & SO_TOTAL) + WARN_ON_ONCE(1); + else if (flags & SO_OBJECTS) + WARN_ON_ONCE(1); + else + x = page->pages; total += x; nodes[node] += x; } -- 2.7.4