Commit e24fc410 authored Jun 23, 2012 by Joonsoo Kim Committed by Pekka Enberg Aug 16, 2012

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>

parent 19c7ff9e

mm/slub.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -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);

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