From 5154175cf1e6e7b1a2ed0295c232e60384944b3f Mon Sep 17 00:00:00 2001 From: Jason Evans Date: Tue, 19 May 2015 17:42:31 -0700 Subject: Fix performance regression in arena_palloc(). Pass large allocation requests to arena_malloc() when possible. This regression was introduced by 155bfa7da18cab0d21d87aa2dce4554166836f5d (Normalize size classes.). --- src/arena.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/src/arena.c b/src/arena.c index a053adf..a3f36b3 100644 --- a/src/arena.c +++ b/src/arena.c @@ -2175,9 +2175,20 @@ arena_palloc(tsd_t *tsd, arena_t *arena, size_t usize, size_t alignment, void *ret; if (usize <= SMALL_MAXCLASS && (alignment < PAGE || (alignment == PAGE - && (usize & PAGE_MASK) == 0))) + && (usize & PAGE_MASK) == 0))) { + /* Small; alignment doesn't require special run placement. */ ret = arena_malloc(tsd, arena, usize, zero, tcache); - else { + } else if (usize <= arena_maxclass && alignment <= PAGE) { + /* + * Large; alignment doesn't require special run placement. + * However, the cached pointer may be at a random offset from + * the base of the run, so do some bit manipulation to retrieve + * the base. + */ + ret = arena_malloc(tsd, arena, usize, zero, tcache); + if (config_cache_oblivious) + ret = (void *)((uintptr_t)ret & ~PAGE_MASK); + } else { if (likely(usize <= arena_maxclass)) { ret = arena_palloc_large(tsd, arena, usize, alignment, zero); -- cgit v0.12