From patchwork Mon Aug 24 12:54:38 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alex Shi X-Patchwork-Id: 11733129 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 192DA14E5 for ; Mon, 24 Aug 2020 12:55:48 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id E4BF120706 for ; Mon, 24 Aug 2020 12:55:47 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E4BF120706 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 0F0678D0008; Mon, 24 Aug 2020 08:55:30 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 07FAC8D0001; Mon, 24 Aug 2020 08:55:29 -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 B98C28D0008; Mon, 24 Aug 2020 08:55:29 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0177.hostedemail.com [216.40.44.177]) by kanga.kvack.org (Postfix) with ESMTP id 9C8B28D0001 for ; Mon, 24 Aug 2020 08:55:29 -0400 (EDT) Received: from smtpin12.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 5E7241EF1 for ; Mon, 24 Aug 2020 12:55:29 +0000 (UTC) X-FDA: 77185458378.12.gun91_2c08ae027053 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin12.hostedemail.com (Postfix) with ESMTP id 1A4F918012603 for ; Mon, 24 Aug 2020 12:55:29 +0000 (UTC) X-Spam-Summary: 1,0,0,dfd5a99446be8b7a,d41d8cd98f00b204,alex.shi@linux.alibaba.com,,RULES_HIT:41:69:355:379:541:800:960:968:973:988:989:1260:1261:1345:1359:1381:1431:1437:1534:1541:1711:1730:1747:1777:1792:2198:2199:2393:2559:2562:2693:2731:2890:3138:3139:3140:3141:3142:3353:3865:3867:3868:3870:3871:3872:4042:4321:5007:6261:6737:6738:8660:9010:10004:11026:11473:11658:11914:12043:12048:12296:12297:12438:12555:12895:12986:13069:13148:13230:13311:13357:13846:14096:14181:14384:14394:14721:14915:21060:21080:21450:21451:21627:21740:21939:30001:30012:30054,0,RBL:115.124.30.43:@linux.alibaba.com:.lbl8.mailshell.net-64.201.201.201 62.20.2.100;04yfnegntqregn9kmc4g3ogc3xwejopzmgmtcnji8x6qd6t3q7u8zat1raxuzyt.s8779rtxujqistzjehdwfcf3ki6oqb5p7tdydsgaoesgf8ksh77utpnui3sum8o.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:none,Custom_rules:0:0:0,LFtime:26,LUA_SUMMARY:none X-HE-Tag: gun91_2c08ae027053 X-Filterd-Recvd-Size: 3182 Received: from out30-43.freemail.mail.aliyun.com (out30-43.freemail.mail.aliyun.com [115.124.30.43]) by imf22.hostedemail.com (Postfix) with ESMTP for ; Mon, 24 Aug 2020 12:55:26 +0000 (UTC) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R181e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01f04427;MF=alex.shi@linux.alibaba.com;NM=1;PH=DS;RN=21;SR=0;TI=SMTPD_---0U6k9-bl_1598273712; Received: from aliy80.localdomain(mailfrom:alex.shi@linux.alibaba.com fp:SMTPD_---0U6k9-bl_1598273712) by smtp.aliyun-inc.com(127.0.0.1); Mon, 24 Aug 2020 20:55:14 +0800 From: Alex Shi To: akpm@linux-foundation.org, mgorman@techsingularity.net, tj@kernel.org, hughd@google.com, khlebnikov@yandex-team.ru, daniel.m.jordan@oracle.com, willy@infradead.org, hannes@cmpxchg.org, lkp@intel.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, shakeelb@google.com, iamjoonsoo.kim@lge.com, richard.weiyang@gmail.com, kirill@shutemov.name, alexander.duyck@gmail.com, rong.a.chen@intel.com, mhocko@suse.com, vdavydov.dev@gmail.com, shy828301@gmail.com Subject: [PATCH v18 05/32] mm/thp: remove code path which never got into Date: Mon, 24 Aug 2020 20:54:38 +0800 Message-Id: <1598273705-69124-6-git-send-email-alex.shi@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1598273705-69124-1-git-send-email-alex.shi@linux.alibaba.com> References: <1598273705-69124-1-git-send-email-alex.shi@linux.alibaba.com> X-Rspamd-Queue-Id: 1A4F918012603 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam01 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: split_huge_page() will never call on a page which isn't on lru list, so this code never got a chance to run, and should not be run, to add tail pages on a lru list which head page isn't there. Although the bug was never triggered, it'better be removed for code correctness, and add a warn for unexpected calling. Signed-off-by: Alex Shi Reviewed-by: Kirill A. Shutemov Cc: Kirill A. Shutemov Cc: Andrew Morton Cc: Johannes Weiner Cc: Matthew Wilcox Cc: Hugh Dickins Cc: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org --- mm/huge_memory.c | 13 ++----------- 1 file changed, 2 insertions(+), 11 deletions(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 739497770a3d..247f53def87b 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -2330,17 +2330,8 @@ static void lru_add_page_tail(struct page *head, struct page *page_tail, /* page reclaim is reclaiming a huge page */ get_page(page_tail); list_add_tail(&page_tail->lru, list); - } else { - /* - * Head page has not yet been counted, as an hpage, - * so we must account for each subpage individually. - * - * Put page_tail on the list at the correct position - * so they all end up in order. - */ - add_page_to_lru_list_tail(page_tail, lruvec, - page_lru(page_tail)); - } + } else + VM_WARN_ON(!PageLRU(head)); } static void __split_huge_page_tail(struct page *head, int tail,