slub: reduce failure of this_cpu_cmpxchg in put_cpu_partial() after unfreezing

In current implementation, after unfreezing, we doesn't touch oldpage,
so it remain 'NOT NULL'. When we call this_cpu_cmpxchg()
with this old oldpage, this_cpu_cmpxchg() is mostly be failed.

We can change value of oldpage to NULL after unfreezing,
because unfreeze_partial() ensure that all the cpu partial slabs is removed
from cpu partial list. In this time, we could expect that
this_cpu_cmpxchg is mostly succeed.

Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Joonsoo Kim <js1304@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
This commit is contained in:
Joonsoo Kim 2012-06-23 03:22:38 +09:00 коммит произвёл Pekka Enberg
Родитель 19c7ff9ecd
Коммит e24fc410f5
1 изменённых файлов: 1 добавлений и 0 удалений

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@ -1962,6 +1962,7 @@ int put_cpu_partial(struct kmem_cache *s, struct page *page, int drain)
local_irq_save(flags);
unfreeze_partials(s);
local_irq_restore(flags);
oldpage = NULL;
pobjects = 0;
pages = 0;
stat(s, CPU_PARTIAL_DRAIN);