Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751681AbdH1BL1 (ORCPT ); Sun, 27 Aug 2017 21:11:27 -0400 Received: from mail-pf0-f194.google.com ([209.85.192.194]:36453 "EHLO mail-pf0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751496AbdH1BL0 (ORCPT ); Sun, 27 Aug 2017 21:11:26 -0400 From: js1304@gmail.com X-Google-Original-From: iamjoonsoo.kim@lge.com To: Andrew Morton Cc: Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Mel Gorman , Vlastimil Babka Subject: [PATCH 1/2] mm/slub: wake up kswapd for initial high order allocation Date: Mon, 28 Aug 2017 10:11:14 +0900 Message-Id: <1503882675-17910-1-git-send-email-iamjoonsoo.kim@lge.com> X-Mailer: git-send-email 2.7.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1590 Lines: 43 From: Joonsoo Kim slub uses higher order allocation than it actually needs. In this case, we don't want to do direct reclaim to make such a high order page since it causes a big latency to the user. Instead, we would like to fallback lower order allocation that it actually needs. However, we also want to get this higher order page in the next time in order to get the best performance and it would be a role of the background thread like as kswapd and kcompactd. To wake up them, we should not clear __GFP_KSWAPD_RECLAIM. Unlike this intention, current code clears __GFP_KSWAPD_RECLAIM so fix it. Note that this patch does some clean up, too. __GFP_NOFAIL is cleared twice so remove one. Signed-off-by: Joonsoo Kim --- mm/slub.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/mm/slub.c b/mm/slub.c index 0dc7397..e1e442c 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -1578,8 +1578,12 @@ static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node) * so we fall-back to the minimum order allocation. */ alloc_gfp = (flags | __GFP_NOWARN | __GFP_NORETRY) & ~__GFP_NOFAIL; - if ((alloc_gfp & __GFP_DIRECT_RECLAIM) && oo_order(oo) > oo_order(s->min)) - alloc_gfp = (alloc_gfp | __GFP_NOMEMALLOC) & ~(__GFP_RECLAIM|__GFP_NOFAIL); + if (oo_order(oo) > oo_order(s->min)) { + if (alloc_gfp & __GFP_DIRECT_RECLAIM) { + alloc_gfp |= __GFP_NOMEMALLOC; + alloc_gfp &= ~__GFP_DIRECT_RECLAIM; + } + } page = alloc_slab_page(s, alloc_gfp, node, oo); if (unlikely(!page)) { -- 2.7.4