Messages in this thread Patch in this message | | | From | Mel Gorman <> | Subject | [PATCH 10/22] Remove a branch by assuming __GFP_HIGH == ALLOC_HIGH | Date | Wed, 22 Apr 2009 14:53:15 +0100 |
| |
Allocations that specify __GFP_HIGH get the ALLOC_HIGH flag. If these flags are equal to each other, we can eliminate a branch.
[akpm@linux-foundation.org: Suggested the hack] Signed-off-by: Mel Gorman <mel@csn.ul.ie> Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> --- mm/page_alloc.c | 6 ++++-- 1 files changed, 4 insertions(+), 2 deletions(-)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 0d23795..4f9cdaa 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1619,14 +1619,16 @@ gfp_to_alloc_flags(gfp_t gfp_mask) int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET; const gfp_t wait = gfp_mask & __GFP_WAIT; + /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */ + BUILD_BUG_ON(__GFP_HIGH != ALLOC_HIGH); + /* * The caller may dip into page reserves a bit more if the caller * cannot run direct reclaim, or if the caller has realtime scheduling * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH). */ - if (gfp_mask & __GFP_HIGH) - alloc_flags |= ALLOC_HIGH; + alloc_flags |= (gfp_mask & __GFP_HIGH); if (!wait) { alloc_flags |= ALLOC_HARDER; -- 1.5.6.5
| |