From: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Date: Mon, 21 Jan 2013 08:01:25 +0000 (+0900)
Subject: slub: correct to calculate num of acquired objects in get_partial_node()
X-Git-Tag: omap-for-v3.10/dt-fixes-for-merge-window~15^2^2~6
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=633b076464da52b3c7bf0f62932fbfc0ea23d8b3;p=pandora-kernel.git

slub: correct to calculate num of acquired objects in get_partial_node()

There is a subtle bug when calculating a number of acquired objects.

Currently, we calculate "available = page->objects - page->inuse",
after acquire_slab() is called in get_partial_node().

In acquire_slab() with mode = 1, we always set new.inuse = page->objects.
So,

	acquire_slab(s, n, page, object == NULL);

	if (!object) {
		c->page = page;
		stat(s, ALLOC_FROM_PARTIAL);
		object = t;
		available = page->objects - page->inuse;

		!!! availabe is always 0 !!!
	...

Therfore, "available > s->cpu_partial / 2" is always false and
we always go to second iteration.
This patch correct this problem.

After that, we don't need return value of put_cpu_partial().
So remove it.

Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
---

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