tree 1438571d206c1d488efb8454c64ae00c51438a2e
parent c84db23c6e587d3ab00a41c51fedf758e1f6ecd4
author Benjamin LaHaise <bcrl@linux.intel.com> 1138791930 -0800
committer Linus Torvalds <torvalds@g5.osdl.org> 1138812795 -0800

[PATCH] Use 32 bit division in slab_put_obj()

Improve the performance of slab_put_obj().  Without the cast, gcc considers
ptrdiff_t a 64 bit signed integer and ends up emitting code to use a full
signed 128 bit divide on EM64T, which is substantially slower than a 32 bit
unsigned divide.

I noticed this when looking at the profile of a case where the slab balance
is just on edge and thrashes back and forth freeing a block.

Signed-off-by: Benjamin LaHaise <benjamin.c.lahaise@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>