From patchwork Tue Aug 11 11:10:31 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alex Shi X-Patchwork-Id: 11709079 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 D6CF914E3 for ; Tue, 11 Aug 2020 11:11:00 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id A03862075D for ; Tue, 11 Aug 2020 11:11:00 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A03862075D 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 925F38D0001; Tue, 11 Aug 2020 07:10:58 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 8D7A36B000A; Tue, 11 Aug 2020 07:10:58 -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 7EDCD8D0001; Tue, 11 Aug 2020 07:10:58 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0199.hostedemail.com [216.40.44.199]) by kanga.kvack.org (Postfix) with ESMTP id 5D6BE6B0008 for ; Tue, 11 Aug 2020 07:10:58 -0400 (EDT) Received: from smtpin07.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 1FC83181AEF0B for ; Tue, 11 Aug 2020 11:10:58 +0000 (UTC) X-FDA: 77138020596.07.legs65_0d0d33126fe2 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin07.hostedemail.com (Postfix) with ESMTP id F087A1803F9AD for ; Tue, 11 Aug 2020 11:10:57 +0000 (UTC) X-Spam-Summary: 1,0,0,,d41d8cd98f00b204,alex.shi@linux.alibaba.com,,RULES_HIT:30001:30012:30054,0,RBL:47.88.44.36:@linux.alibaba.com:.lbl8.mailshell.net-64.10.201.10 62.18.0.100;04ygkcwnsi9wbeth5ijcx844fns6topzmgmtcnji8x6qd6t3q7u8zat1raxuzyt.s8779rtxujqistzjehdwfcf3ki6oqb5p7tdydsgaoesgf8ksh77utpnui3sum8o.w-lbl8.mailshell.net-223.238.255.100;47.88.44.36-irl.urbl.hostedemail.com-127.0.0.150,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:25,LUA_SUMMARY:none X-HE-Tag: legs65_0d0d33126fe2 X-Filterd-Recvd-Size: 2894 Received: from out4436.biz.mail.alibaba.com (out4436.biz.mail.alibaba.com [47.88.44.36]) by imf37.hostedemail.com (Postfix) with ESMTP for ; Tue, 11 Aug 2020 11:10:56 +0000 (UTC) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R121e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e01422;MF=alex.shi@linux.alibaba.com;NM=1;PH=DS;RN=7;SR=0;TI=SMTPD_---0U5TLMT5_1597144252; Received: from aliy80.localdomain(mailfrom:alex.shi@linux.alibaba.com fp:SMTPD_---0U5TLMT5_1597144252) by smtp.aliyun-inc.com(127.0.0.1); Tue, 11 Aug 2020 19:10:53 +0800 From: Alex Shi To: akpm@linux-foundation.org Cc: "Kirill A. Shutemov" , Johannes Weiner , Matthew Wilcox , Hugh Dickins , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [Resend PATCH 5/6] mm/thp: remove code path which never got into Date: Tue, 11 Aug 2020 19:10:31 +0800 Message-Id: <1597144232-11370-5-git-send-email-alex.shi@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1597144232-11370-1-git-send-email-alex.shi@linux.alibaba.com> References: <1597144232-11370-1-git-send-email-alex.shi@linux.alibaba.com> X-Rspamd-Queue-Id: F087A1803F9AD X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam03 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 8cecd39bd8b7..d55e3006c63f 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -2332,17 +2332,8 @@ 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,