From patchwork Mon Jan 18 07:41:26 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wu Yan X-Patchwork-Id: 12026705 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8B8C3C433E0 for ; Mon, 18 Jan 2021 07:41:51 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id DC8F022242 for ; Mon, 18 Jan 2021 07:41:50 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DC8F022242 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=tcl.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id A63646B0280; Mon, 18 Jan 2021 02:41:49 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id A14AB6B0281; Mon, 18 Jan 2021 02:41:49 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 92A426B0282; Mon, 18 Jan 2021 02:41:49 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0067.hostedemail.com [216.40.44.67]) by kanga.kvack.org (Postfix) with ESMTP id 79C416B0280 for ; Mon, 18 Jan 2021 02:41:49 -0500 (EST) Received: from smtpin13.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 31400824999B for ; Mon, 18 Jan 2021 07:41:49 +0000 (UTC) X-FDA: 77718101538.13.meal97_181682627547 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin13.hostedemail.com (Postfix) with ESMTP id 1309818140B89 for ; Mon, 18 Jan 2021 07:41:49 +0000 (UTC) X-HE-Tag: meal97_181682627547 X-Filterd-Recvd-Size: 4552 Received: from support.corp-email.com (support.corp-email.com [222.73.234.235]) by imf41.hostedemail.com (Postfix) with ESMTP for ; Mon, 18 Jan 2021 07:41:46 +0000 (UTC) Received: from ([183.47.25.45]) by support.corp-email.com ((LNX1044)) with ASMTP (SSL) id LYH00040; Mon, 18 Jan 2021 15:41:40 +0800 Received: from GCY-EXS-15.TCL.com (10.74.128.165) by GCY-EXS-07.TCL.com (10.74.128.157) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2106.2; Mon, 18 Jan 2021 15:41:40 +0800 Received: from localhost.localdomain (172.16.34.38) by GCY-EXS-15.TCL.com (10.74.128.165) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2106.2; Mon, 18 Jan 2021 15:41:39 +0800 From: Rokudo Yan To: CC: , , , , , , , , , Subject: [PATCH] mm, compaction: move high_pfn to the for loop scope. Date: Mon, 18 Jan 2021 15:41:26 +0800 Message-ID: <20210118074126.1838139-1-wu-yan@tcl.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210112142711.b82cf36abaa7ff04773e212f@linux-foundation.org> References: <20210112142711.b82cf36abaa7ff04773e212f@linux-foundation.org> MIME-Version: 1.0 X-Originating-IP: [172.16.34.38] X-ClientProxiedBy: GCY-EXS-01.TCL.com (10.74.128.151) To GCY-EXS-15.TCL.com (10.74.128.165) tUid: 2021118154140b2abbdfb168f8823bfb5153861e0b1ce X-Abuse-Reports-To: service@corp-email.com Abuse-Reports-To: service@corp-email.com X-Complaints-To: service@corp-email.com X-Report-Abuse-To: service@corp-email.com 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: In fast_isolate_freepages, high_pfn will be used if a prefered one(PFN >= low_fn) not found. But the high_pfn is not reset before searching an free area, so when it was used as freepage, it may from another free area searched before. And move_freelist_head(freelist, freepage) will have unexpected behavior(eg. corrupt the MOVABLE freelist) Unable to handle kernel paging request at virtual address dead000000000200 Mem abort info: ESR = 0x96000044 Exception class = DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 Data abort info: ISV = 0, ISS = 0x00000044 CM = 0, WnR = 1 [dead000000000200] address between user and kernel address ranges -000|list_cut_before(inline) -000|move_freelist_head(inline) -000|fast_isolate_freepages(inline) -000|isolate_freepages(inline) -000|compaction_alloc(?, ?) -001|unmap_and_move(inline) -001|migrate_pages([NSD:0xFFFFFF80088CBBD0] from = 0xFFFFFF80088CBD88, [NSD:0xFFFFFF80088CBBC8] get_new_p -002|__read_once_size(inline) -002|static_key_count(inline) -002|static_key_false(inline) -002|trace_mm_compaction_migratepages(inline) -002|compact_zone(?, [NSD:0xFFFFFF80088CBCB0] capc = 0x0) -003|kcompactd_do_work(inline) -003|kcompactd([X19] p = 0xFFFFFF93227FBC40) -004|kthread([X20] _create = 0xFFFFFFE1AFB26380) -005|ret_from_fork(asm) ---|end of frame The issue was reported on an smart phone product with 6GB ram and 3GB zram as swap device. This patch fixes the issue by reset high_pfn before searching each free area, which ensure freepage and freelist match when call move_freelist_head in fast_isolate_freepages(). Fixes: 5a811889de10f1eb ("mm, compaction: use free lists to quickly locate a migration target") Signed-off-by: Rokudo Yan Acked-by: Mel Gorman --- mm/compaction.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/mm/compaction.c b/mm/compaction.c index cc1a7f600a86..75f0e550b18f 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -1303,7 +1303,7 @@ fast_isolate_freepages(struct compact_control *cc) { unsigned int limit = min(1U, freelist_scan_limit(cc) >> 1); unsigned int nr_scanned = 0; - unsigned long low_pfn, min_pfn, high_pfn = 0, highest = 0; + unsigned long low_pfn, min_pfn, highest = 0; unsigned long nr_isolated = 0; unsigned long distance; struct page *page = NULL; @@ -1348,6 +1348,7 @@ fast_isolate_freepages(struct compact_control *cc) struct page *freepage; unsigned long flags; unsigned int order_scanned = 0; + unsigned long high_pfn = 0; if (!area->nr_free) continue;