From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9CD5BC77B60 for ; Fri, 28 Apr 2023 10:09:08 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 2F1236B0072; Fri, 28 Apr 2023 06:09:08 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 2A16A6B0074; Fri, 28 Apr 2023 06:09:08 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 190846B0075; Fri, 28 Apr 2023 06:09:08 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 0AA276B0072 for ; Fri, 28 Apr 2023 06:09:08 -0400 (EDT) Received: from smtpin17.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id CFE2EA026A for ; Fri, 28 Apr 2023 10:09:07 +0000 (UTC) X-FDA: 80730376734.17.BEBD158 Received: from out-40.mta1.migadu.com (out-40.mta1.migadu.com [95.215.58.40]) by imf03.hostedemail.com (Postfix) with ESMTP id 1058720015 for ; Fri, 28 Apr 2023 10:09:04 +0000 (UTC) Authentication-Results: imf03.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=PtApRLYm; spf=pass (imf03.hostedemail.com: domain of yajun.deng@linux.dev designates 95.215.58.40 as permitted sender) smtp.mailfrom=yajun.deng@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1682676545; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:references:dkim-signature; bh=PVAO+BlDHMujnNKZN8jYnO3UHWhcSJNRlz/2YLsn0QQ=; b=dam2ob77oB6o/7PNYXOOgerYixuhV+bR4NH6y6jcJBxfLNIcez1UfgK7MFuYXhnmYgHJrc hDG2b8QQI+UqfQybVEYhjvSEVi5TmB2TyFiupUMruxvVPVuM2vZCoT7aM1W/CkiS3SzyI7 0Cf5mn5iPnfdM+NMPX6jB7RJZk2P6oU= ARC-Authentication-Results: i=1; imf03.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=PtApRLYm; spf=pass (imf03.hostedemail.com: domain of yajun.deng@linux.dev designates 95.215.58.40 as permitted sender) smtp.mailfrom=yajun.deng@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1682676545; a=rsa-sha256; cv=none; b=Rx8Q/f9JAML6jheb26j+CLpsGpxcXzMu8u6E+ujzW4RqRkR2Uc9jZFd/iHo6qPs5BHhsGq JWqo9MaZNW6MlZsCGSwVfYVU7XIKdGL/O1qIhXa1ueod+Ew7+ALMKG3FQ+5qN3LOJocSYh e0M9km7VHLKowtXVAqYpQm2OEVxyDiM= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1682676542; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=PVAO+BlDHMujnNKZN8jYnO3UHWhcSJNRlz/2YLsn0QQ=; b=PtApRLYmSe4NU9sJuZXacjEEDoHP1mUvWTAOjzUNY7o8SF1NHkhSVS+YleS4s7lmUzGlQ2 zrmrhV1KalImjhj7cWutu7WsxuZNpJjVsJeRb98zodWiH3EZOen6rrnJff00fV2Zxzib60 OeQR9ZEO9U7Ogw+A7sH+fyNN+747kwE= From: Yajun Deng To: david@redhat.com, osalvador@suse.de, akpm@linux-foundation.org, mhocko@suse.com Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Yajun Deng Subject: [PATCH] mm/memory_hotplug: fix dead loop in offline_pages() Date: Fri, 28 Apr 2023 18:08:46 +0800 Message-Id: <20230428100846.95535-1-yajun.deng@linux.dev> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT X-Rspam-User: X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 1058720015 X-Stat-Signature: x7gtx551aitgzwg9ybe6d1bm1h8n84j3 X-HE-Tag: 1682676544-50869 X-HE-Meta: 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 UbA6k/Xp c2cushDK5KdkrPxhh6UirU7ds8jyzsr+WTcq3XsIO1TB+7wXZUsQyeXi9/JEEwqn0QJMG+mb9Qk/WZRvW2L7sSCcoasoMlj59CNrENbWLa8h6mUWtJsr7SX4fuxeRVzenuXgw 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: When migration failure in do_migrate_range() and then the scan_movable_pages() will most likely return the same movable pfn. In this case, there is no condition to bail out, they will always run like this: ... [878020.623959] migrating pfn 1727813 failed ret:1 [878020.623960] page:00000000faa9673c refcount:3 mapcount:0 mapping:00000000144ccd79 index:0x14280025 pfn:0x1727813 [878020.623962] memcg:ffffa0ff82d5a000 [878020.623962] aops:def_blk_aops ino:fd00001 [878020.623964] flags: 0x17ffffc000206a(referenced|dirty|active|workingset|private|node=0|zone=2|lastcpupid=0x1fffff) [878020.623966] raw: 0017ffffc000206a ffffb0d14f50fbd8 ffffb0d14f50fbd8 ffffa0ff9c155018 [878020.623967] raw: 0000000014280025 ffffa10327d702d8 00000003ffffffff ffffa0ff82d5a000 [878020.623968] page dumped because: migration failure [878020.626196] migrating pfn 1727813 failed ret:1 [878020.626198] page:00000000faa9673c refcount:3 mapcount:0 mapping:00000000144ccd79 index:0x14280025 pfn:0x1727813 [878020.626200] memcg:ffffa0ff82d5a000 [878020.626200] aops:def_blk_aops ino:fd00001 [878020.626202] flags: 0x17ffffc000206a(referenced|dirty|active|workingset|private|node=0|zone=2|lastcpupid=0x1fffff) [878020.626204] raw: 0017ffffc000206a ffffb0d14f50fbd8 ffffb0d14f50fbd8 ffffa0ff9c155018 [878020.626205] raw: 0000000014280025 ffffa10327d702d8 00000003ffffffff ffffa0ff82d5a000 [878020.626206] page dumped because: migration failure ... Bail out when migration failures reach 3 times. Fixes: bb8965bd82fd ("mm, memory_hotplug: deobfuscate migration part of offlining") Signed-off-by: Yajun Deng --- mm/memory_hotplug.c | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-) diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 8e0fa209d533..72dd385b8892 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1800,11 +1800,12 @@ int __ref offline_pages(unsigned long start_pfn, unsigned long nr_pages, struct zone *zone, struct memory_group *group) { const unsigned long end_pfn = start_pfn + nr_pages; - unsigned long pfn, system_ram_pages = 0; + unsigned long pfn, tmp_pfn, system_ram_pages = 0; const int node = zone_to_nid(zone); unsigned long flags; struct memory_notify arg; char *reason; + int count = 0; int ret; /* @@ -1887,12 +1888,20 @@ int __ref offline_pages(unsigned long start_pfn, unsigned long nr_pages, cond_resched(); + tmp_pfn = pfn; ret = scan_movable_pages(pfn, end_pfn, &pfn); if (!ret) { - /* - * TODO: fatal migration failures should bail - * out - */ + if (pfn == tmp_pfn) + count++; + else + count = 0; + + if (unlikely(count == 3)) { + ret = -EBUSY; + reason = "migration failure"; + goto failed_removal_isolated; + } + do_migrate_range(pfn, end_pfn); } } while (!ret); -- 2.25.1