tree 6ee56b3248ccd89db45f6bd8d532005fc61cc00b
parent 53e15af03be4fdaaf20802d78f141487d7272985
author Christoph Lameter <clameter@sgi.com> 1178488184 -0700
committer Linus Torvalds <torvalds@woody.linux-foundation.org> 1178565174 -0700

SLUB: Add MIN_PARTIAL

We leave a mininum of partial slabs on nodes when we search for
partial slabs on other node. Define a constant for that value.

Then modify slub to keep MIN_PARTIAL slabs around.

This avoids bad situations where a function frees the last object
in a slab (which results in the page being returned to the page
allocator) only to then allocate one again (which requires getting
a page back from the page allocator if the partial list was empty).
Keeping a couple of slabs on the partial list reduces overhead.

Empty slabs are added to the end of the partial list to insure that
partially allocated slabs are consumed first (defragmentation).

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>