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: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Pekka 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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/gfp.h b/include/linux/gfp.h
index 3760e7c..549ec55 100644
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h
@@ -172,24 +172,16 @@
#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)
{
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index cbed869..d58df90 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1458,7 +1458,7 @@
* 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 @@
got_pg:
return page;
}
-EXPORT_SYMBOL(__alloc_pages_internal);
+EXPORT_SYMBOL(__alloc_pages_nodemask);
/*
* Common helper functions.