From: Mel Gorman Date: Fri, 20 May 2016 00:13:56 +0000 (-0700) Subject: mm, page_alloc: move __GFP_HARDWALL modifications out of the fastpath X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=83d4ca8148fd9092;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git mm, page_alloc: move __GFP_HARDWALL modifications out of the fastpath __GFP_HARDWALL only has meaning in the context of cpusets but the fast path always applies the flag on the first attempt. Move the manipulations into the cpuset paths where they will be masked by a static branch in the common case. With the other micro-optimisations in this series combined, the impact on a page allocator microbenchmark is 4.6.0-rc2 4.6.0-rc2 decstat-v1r20 micro-v1r20 Min alloc-odr0-1 381.00 ( 0.00%) 377.00 ( 1.05%) Min alloc-odr0-2 275.00 ( 0.00%) 273.00 ( 0.73%) Min alloc-odr0-4 229.00 ( 0.00%) 226.00 ( 1.31%) Min alloc-odr0-8 199.00 ( 0.00%) 196.00 ( 1.51%) Min alloc-odr0-16 186.00 ( 0.00%) 183.00 ( 1.61%) Min alloc-odr0-32 179.00 ( 0.00%) 175.00 ( 2.23%) Min alloc-odr0-64 174.00 ( 0.00%) 172.00 ( 1.15%) Min alloc-odr0-128 172.00 ( 0.00%) 170.00 ( 1.16%) Min alloc-odr0-256 181.00 ( 0.00%) 183.00 ( -1.10%) Min alloc-odr0-512 193.00 ( 0.00%) 191.00 ( 1.04%) Min alloc-odr0-1024 201.00 ( 0.00%) 199.00 ( 1.00%) Min alloc-odr0-2048 206.00 ( 0.00%) 204.00 ( 0.97%) Min alloc-odr0-4096 212.00 ( 0.00%) 210.00 ( 0.94%) Min alloc-odr0-8192 215.00 ( 0.00%) 213.00 ( 0.93%) Min alloc-odr0-16384 216.00 ( 0.00%) 214.00 ( 0.93%) Signed-off-by: Mel Gorman Acked-by: Vlastimil Babka Cc: Jesper Dangaard Brouer Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/mm/page_alloc.c b/mm/page_alloc.c index f9ca6cc553c7..48afc1a42bbd 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -3350,7 +3350,7 @@ __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order, struct page *page; unsigned int cpuset_mems_cookie; unsigned int alloc_flags = ALLOC_WMARK_LOW|ALLOC_FAIR; - gfp_t alloc_mask; /* The gfp_t that was actually used for allocation */ + gfp_t alloc_mask = gfp_mask; /* The gfp_t that was actually used for allocation */ struct alloc_context ac = { .high_zoneidx = gfp_zone(gfp_mask), .zonelist = zonelist, @@ -3359,6 +3359,7 @@ __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order, }; if (cpusets_enabled()) { + alloc_mask |= __GFP_HARDWALL; alloc_flags |= ALLOC_CPUSET; if (!ac.nodemask) ac.nodemask = &cpuset_current_mems_allowed; @@ -3401,7 +3402,6 @@ retry_cpuset: ac.classzone_idx = zonelist_zone_idx(preferred_zoneref); /* First allocation attempt */ - alloc_mask = gfp_mask|__GFP_HARDWALL; page = get_page_from_freelist(alloc_mask, order, alloc_flags, &ac); if (unlikely(!page)) { /* @@ -3427,8 +3427,10 @@ out: * the mask is being updated. If a page allocation is about to fail, * check if the cpuset changed during allocation and if so, retry. */ - if (unlikely(!page && read_mems_allowed_retry(cpuset_mems_cookie))) + if (unlikely(!page && read_mems_allowed_retry(cpuset_mems_cookie))) { + alloc_mask = gfp_mask; goto retry_cpuset; + } return page; }