Commit 8afb1474 authored by Li Zefan's avatar Li Zefan Committed by Pekka Enberg

slub: Fix calculation of cpu slabs

  /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 49e22585
("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.

Cc: <stable@vger.kernel.org> # 3.2+
Acked-by: default avatarChristoph Lameter <cl@linux.com>
Reviewed-by: default avatarWanpeng Li <liwanp@linux.vnet.ibm.com>
Signed-off-by: default avatarLi Zefan <lizefan@huawei.com>
Signed-off-by: default avatarPekka Enberg <penberg@kernel.org>
parent e1168c2c
...@@ -4299,7 +4299,13 @@ static ssize_t show_slab_objects(struct kmem_cache *s, ...@@ -4299,7 +4299,13 @@ static ssize_t show_slab_objects(struct kmem_cache *s,
page = ACCESS_ONCE(c->partial); page = ACCESS_ONCE(c->partial);
if (page) { 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; total += x;
nodes[node] += x; nodes[node] += x;
} }
......
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