From patchwork Tue Oct 27 17:04:20 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hui Su X-Patchwork-Id: 11861057 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 74AE9921 for ; Tue, 27 Oct 2020 17:05:15 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id C35B921D7B for ; Tue, 27 Oct 2020 17:05:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b="pTvlvA8l" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C35B921D7B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=163.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id AAE146B0072; Tue, 27 Oct 2020 13:05:13 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id A5D966B0073; Tue, 27 Oct 2020 13:05:13 -0400 (EDT) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 94CE96B0074; Tue, 27 Oct 2020 13:05:13 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0057.hostedemail.com [216.40.44.57]) by kanga.kvack.org (Postfix) with ESMTP id 66CC76B0072 for ; Tue, 27 Oct 2020 13:05:13 -0400 (EDT) Received: from smtpin23.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 04DA01EE6 for ; Tue, 27 Oct 2020 17:05:13 +0000 (UTC) X-FDA: 77418330906.23.fact18_2b0ceee2727d Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin23.hostedemail.com (Postfix) with ESMTP id 0DCF537628 for ; Tue, 27 Oct 2020 17:05:09 +0000 (UTC) X-Spam-Summary: 1,0,0,fb7fc2724907c175,d41d8cd98f00b204,sh_def@163.com,,RULES_HIT:41:355:379:582:800:960:973:988:989:1152:1260:1277:1312:1313:1314:1345:1381:1516:1518:1519:1534:1541:1568:1593:1594:1595:1596:1711:1714:1730:1747:1777:1792:2393:2559:2562:3138:3139:3140:3141:3142:3151:3866:3870:3871:4321:4605:5007:6261:6653:10004:10400:10450:10455:11026:11334:11658:11914:12048:12296:12297:12555:12895:13069:13311:13357:13439:13895:14096:14097:14181:14394:14721:19904:19999:21080:21600:21627:21990:30054,0,RBL:220.181.12.15:@163.com:.lbl8.mailshell.net-66.100.201.100 62.50.2.100;04yr4cbs6cwcue4fdmduayrisz3h9ycciuocyj6pj6yubhrdckd7kzdbgui9fz9.cchs7bqkpqubcqpgnh3ypfzya16f9e8rwkbeieeybarq3pcwjfy9yjy4jbzd1ih.w-lbl8.mailshell.net-223.238.255.100,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fp,MSBL:0,DNSBL:neutral,Custom_rules:0:0:0,LFtime:24,LUA_SUMMARY:none X-HE-Tag: fact18_2b0ceee2727d X-Filterd-Recvd-Size: 2777 Received: from m12-15.163.com (m12-15.163.com [220.181.12.15]) by imf11.hostedemail.com (Postfix) with ESMTP for ; Tue, 27 Oct 2020 17:05:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=Date:From:Subject:Message-ID:MIME-Version; bh=7iC1B g63LnwLLyjyKl+KfHw1n3wjgF5SyvewtftGbW8=; b=pTvlvA8lpXFsnDPlnTUpq VqIxb5kQGIVq+goQmwZSgck2RaXBAEeQpcA3XhbsXy09d3CLA9/2BVPdFJ41XquE fsEK9QqrAXci31PYUp4Lv8YBOokmEhkXHDI3cVQc5+LPskLXrRkI8i0aoVhVKb4d 5MC40oNMxV10/sYr4KK4Os= Received: from localhost (unknown [101.86.209.121]) by smtp11 (Coremail) with SMTP id D8CowADHlfIUU5hfgOmYFA--.51943S2; Wed, 28 Oct 2020 01:04:20 +0800 (CST) Date: Wed, 28 Oct 2020 01:04:20 +0800 From: Hui Su To: akpm@linux-foundation.org, gustavo@embeddedor.com, sh_def@163.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH] mm/list_lru: optimize condition of exiting the loop Message-ID: <20201027170420.GA61326@rlk> MIME-Version: 1.0 Content-Disposition: inline X-CM-TRANSID: D8CowADHlfIUU5hfgOmYFA--.51943S2 X-Coremail-Antispam: 1Uf129KBjvJXoWrtryDtr47uF1fur4UJrW8WFg_yoW8Jr4Upa n09rW7KFyxXF48u3y8J39ruF10grWUCrW7KrZruw1jyw13JFZxX39FkrW2qF98XFWxXFyf GryDCF45uF4UGwUanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x07UJwIkUUUUU= X-Originating-IP: [101.86.209.121] X-CM-SenderInfo: xvkbvvri6rljoofrz/1tbiIBTKX10TB9dVFAAAs+ X-Bogosity: Ham, tests=bogofilter, spamicity=0.300051, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: In list_lru_walk(), nr_to_walk type is 'unsigned long', so nr_to_walk won't be '< 0'. In list_lru_walk_node(), nr_to_walk type is 'unsigned long', so *nr_to_walk won't be '< 0' too. We can use '!nr_to_walk' instead of 'nr_to_walk <= 0', which is more precise. Signed-off-by: Hui Su --- include/linux/list_lru.h | 2 +- mm/list_lru.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/include/linux/list_lru.h b/include/linux/list_lru.h index 9dcaa3e582c9..b7bc4a2636b9 100644 --- a/include/linux/list_lru.h +++ b/include/linux/list_lru.h @@ -214,7 +214,7 @@ list_lru_walk(struct list_lru *lru, list_lru_walk_cb isolate, for_each_node_state(nid, N_NORMAL_MEMORY) { isolated += list_lru_walk_node(lru, nid, isolate, cb_arg, &nr_to_walk); - if (nr_to_walk <= 0) + if (!nr_to_walk) break; } return isolated; diff --git a/mm/list_lru.c b/mm/list_lru.c index 5aa6e44bc2ae..39b8d467159d 100644 --- a/mm/list_lru.c +++ b/mm/list_lru.c @@ -304,7 +304,7 @@ unsigned long list_lru_walk_node(struct list_lru *lru, int nid, nr_to_walk); spin_unlock(&nlru->lock); - if (*nr_to_walk <= 0) + if (!*nr_to_walk) break; } }