Commit d239171e authored by Mel Gorman's avatar Mel Gorman Committed by Linus Torvalds
Browse files

page allocator: replace __alloc_pages_internal() with __alloc_pages_nodemask()



The start of a large patch series to clean up and optimise the page
allocator.

The performance improvements are in a wide range depending on the exact
machine but the results I've seen so fair are approximately;

kernbench:	0	to	 0.12% (elapsed time)
		0.49%	to	 3.20% (sys time)
aim9:		-4%	to	30% (for page_test and brk_test)
tbench:		-1%	to	 4%
hackbench:	-2.5%	to	 3.45% (mostly within the noise though)
netperf-udp	-1.34%  to	 4.06% (varies between machines a bit)
netperf-tcp	-0.44%  to	 5.22% (varies between machines a bit)

I haven't sysbench figures at hand, but previously they were within the
-0.5% to 2% range.

On netperf, the client and server were bound to opposite number CPUs to
maximise the problems with cache line bouncing of the struct pages so I
expect different people to report different results for netperf depending
on their exact machine and how they ran the test (different machines, same
cpus client/server, shared cache but two threads client/server, different
socket client/server etc).

I also measured the vmlinux sizes for a single x86-based config with
CONFIG_DEBUG_INFO enabled but not CONFIG_DEBUG_VM.  The core of the
.config is based on the Debian Lenny kernel config so I expect it to be
reasonably typical.

This patch:

__alloc_pages_internal is the core page allocator function but essentially
it is an alias of __alloc_pages_nodemask.  Naming a publicly available and
exported function "internal" is also a big ugly.  This patch renames
__alloc_pages_internal() to __alloc_pages_nodemask() and deletes the old
nodemask function.

Warning - This patch renames an exported symbol.  No kernel driver is
affected by external drivers calling __alloc_pages_internal() should
change the call to __alloc_pages_nodemask() without any alteration of
parameters.
Signed-off-by: default avatarMel Gorman <mel@csn.ul.ie>
Reviewed-by: default avatarChristoph Lameter <cl@linux-foundation.org>
Reviewed-by: default avatarKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: default avatarPekka Enberg <penberg@cs.helsinki.fi>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 6c0db466
......@@ -172,24 +172,16 @@ static inline void arch_alloc_page(struct page *page, int order) { }
#endif
struct page *
__alloc_pages_internal(gfp_t gfp_mask, unsigned int order,
__alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
struct zonelist *zonelist, nodemask_t *nodemask);
static inline struct page *
__alloc_pages(gfp_t gfp_mask, unsigned int order,
struct zonelist *zonelist)
{
return __alloc_pages_internal(gfp_mask, order, zonelist, NULL);
return __alloc_pages_nodemask(gfp_mask, order, zonelist, NULL);
}
static inline struct page *
__alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
struct zonelist *zonelist, nodemask_t *nodemask)
{
return __alloc_pages_internal(gfp_mask, order, zonelist, nodemask);
}
static inline struct page *alloc_pages_node(int nid, gfp_t gfp_mask,
unsigned int order)
{
......
......@@ -1458,7 +1458,7 @@ try_next_zone:
* This is the 'heart' of the zoned buddy allocator.
*/
struct page *
__alloc_pages_internal(gfp_t gfp_mask, unsigned int order,
__alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
struct zonelist *zonelist, nodemask_t *nodemask)
{
const gfp_t wait = gfp_mask & __GFP_WAIT;
......@@ -1667,7 +1667,7 @@ nopage:
got_pg:
return page;
}
EXPORT_SYMBOL(__alloc_pages_internal);
EXPORT_SYMBOL(__alloc_pages_nodemask);
/*
* Common helper functions.
......
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