The patch titled page allocator: remove a branch by assuming __GFP_HIGH == ALLOC_HIGH has been added to the -mm tree. Its filename is page-allocator-remove-a-branch-by-assuming-__gfp_high-==-alloc_high.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find out what to do about this The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: page allocator: remove a branch by assuming __GFP_HIGH == ALLOC_HIGH From: Mel Gorman <mel@xxxxxxxxx> Allocations that specify __GFP_HIGH get the ALLOC_HIGH flag. If these flags are equal to each other, we can eliminate a branch. [akpm@xxxxxxxxxxxxxxxxxxxx: Suggested the hack] Signed-off-by: Mel Gorman <mel@xxxxxxxxx> Reviewed-by: Pekka Enberg <penberg@xxxxxxxxxxxxxx> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx> Cc: Christoph Lameter <cl@xxxxxxxxxxxxxxxxxxxx> Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> Cc: Nick Piggin <nickpiggin@xxxxxxxxxxxx> Cc: Dave Hansen <dave@xxxxxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/page_alloc.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff -puN mm/page_alloc.c~page-allocator-remove-a-branch-by-assuming-__gfp_high-==-alloc_high mm/page_alloc.c --- a/mm/page_alloc.c~page-allocator-remove-a-branch-by-assuming-__gfp_high-==-alloc_high +++ a/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; _ Patches currently in -mm which might be from mel@xxxxxxxxx are vmscan-low-order-lumpy-reclaim-also-should-use-pageout_io_sync.patch page-allocator-replace-__alloc_pages_internal-with-__alloc_pages_nodemask.patch page-allocator-do-not-sanity-check-order-in-the-fast-path.patch page-allocator-do-not-sanity-check-order-in-the-fast-path-fix.patch page-allocator-do-not-check-numa-node-id-when-the-caller-knows-the-node-is-valid.patch page-allocator-check-only-once-if-the-zonelist-is-suitable-for-the-allocation.patch page-allocator-break-up-the-allocator-entry-point-into-fast-and-slow-paths.patch page-allocator-move-check-for-disabled-anti-fragmentation-out-of-fastpath.patch page-allocator-calculate-the-preferred-zone-for-allocation-only-once.patch page-allocator-calculate-the-preferred-zone-for-allocation-only-once-fix.patch page-allocator-calculate-the-migratetype-for-allocation-only-once.patch page-allocator-calculate-the-alloc_flags-for-allocation-only-once.patch page-allocator-remove-a-branch-by-assuming-__gfp_high-==-alloc_high.patch page-allocator-inline-__rmqueue_smallest.patch page-allocator-inline-buffered_rmqueue.patch page-allocator-inline-__rmqueue_fallback.patch page-allocator-do-not-call-get_pageblock_migratetype-more-than-necessary.patch page-allocator-do-not-disable-interrupts-in-free_page_mlock.patch page-allocator-do-not-setup-zonelist-cache-when-there-is-only-one-node.patch page-allocator-do-not-check-for-compound-pages-during-the-page-allocator-sanity-checks.patch page-allocator-use-allocation-flags-as-an-index-to-the-zone-watermark.patch page-allocator-update-nr_free_pages-only-as-necessary.patch page-allocator-get-the-pageblock-migratetype-without-disabling-interrupts.patch page-allocator-use-a-pre-calculated-value-instead-of-num_online_nodes-in-fast-paths.patch page-allocator-slab-use-nr_online_nodes-to-check-for-a-numa-platform.patch add-debugging-aid-for-memory-initialisation-problems.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html