From: Hisashi Hifumi Subject: [PATCH] vmscan: set try_to_release_page's gfp_mask to 0 Date: Wed, 13 Aug 2008 11:21:16 +0900 Message-ID: <6.0.0.20.2.20080813111835.03d345b0@172.19.0.2> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-ext4@vger.kernel.org To: akpm@linux-foundation.org Return-path: Received: from serv2.oss.ntt.co.jp ([222.151.198.100]:50683 "EHLO serv2.oss.ntt.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752165AbYHMCX0 (ORCPT ); Tue, 12 Aug 2008 22:23:26 -0400 Sender: linux-ext4-owner@vger.kernel.org List-ID: Hi. shrink_page_list passes gfp_mask to try_to_release_page. When shrink_page_list is called from kswapd or buddy system, gfp_mask is set and (gfp_mask & __GFP_WAIT) and (gfp_mask & __GFP_FS) check is positive. releasepage of jbd/jbd2(ext3/4, ocfs2) and XFS use this parameter. If try_to_free_page fails due to bh busy in jbd/jbd2, jbd/jbd2 lets a thread wait for committing transaction. I think this has big performance impacts for vmscan. So I modified shrink_page_list not to pass gfp_mask to try_to_release_page in ordered to improve vmscan performance. Thanks. Signed-off-by: Hisashi Hifumi diff -Nrup linux-2.6.27-rc2.org/mm/vmscan.c linux-2.6.27-rc2.vmscan/mm/vmscan.c --- linux-2.6.27-rc2.org/mm/vmscan.c 2008-08-11 14:33:24.000000000 +0900 +++ linux-2.6.27-rc2.vmscan/mm/vmscan.c 2008-08-12 18:57:05.000000000 +0900 @@ -614,7 +614,7 @@ static unsigned long shrink_page_list(st * Otherwise, leave the page on the LRU so it is swappable. */ if (PagePrivate(page)) { - if (!try_to_release_page(page, sc->gfp_mask)) + if (!try_to_release_page(page, 0)) goto activate_locked; if (!mapping && page_count(page) == 1) { unlock_page(page);