From patchwork Tue Jun 29 02:41:10 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Morton X-Patchwork-Id: 12349177 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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 C71D6C11F64 for ; Tue, 29 Jun 2021 02:41:13 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 776EB61D0C for ; Tue, 29 Jun 2021 02:41:13 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 776EB61D0C Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id CB1D08D010C; Mon, 28 Jun 2021 22:41:12 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C618B8D00F0; Mon, 28 Jun 2021 22:41:12 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B02E28D010C; Mon, 28 Jun 2021 22:41:12 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0251.hostedemail.com [216.40.44.251]) by kanga.kvack.org (Postfix) with ESMTP id 8102E8D00F0 for ; Mon, 28 Jun 2021 22:41:12 -0400 (EDT) Received: from smtpin02.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 798C71F363 for ; Tue, 29 Jun 2021 02:41:12 +0000 (UTC) X-FDA: 78305209584.02.9BD53C4 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf04.hostedemail.com (Postfix) with ESMTP id 38CA6376 for ; Tue, 29 Jun 2021 02:41:12 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id 43A25611AE; Tue, 29 Jun 2021 02:41:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1624934471; bh=qxUSIKFqxFA0UeD8NL5XjNfNuRTUNkEADefjr07GDIA=; h=Date:From:To:Subject:In-Reply-To:From; b=r9koi1QweSFwrlYFrd1scM64VXrH/LzUeIgd/lTdsz/p22zRxl7iciyuFxCAG7H4d A1+45ipOOERL+5Jdny3spuHK1arE2U4i/lO294jeBObCmWSkxgyjEQu9bIk70ohMmo rtBI1lyjMIhJrjz1xK8ZaUJFUN1T5syN4rbQX7MU= Date: Mon, 28 Jun 2021 19:41:10 -0700 From: Andrew Morton To: akpm@linux-foundation.org, atomlin@redhat.com, linux-mm@kvack.org, mhocko@suse.com, mm-commits@vger.kernel.org, torvalds@linux-foundation.org, vbabka@suse.cz, willy@infradead.org Subject: [patch 151/192] mm/page_alloc: bail out on fatal signal during reclaim/compaction retry attempt Message-ID: <20210629024110.9HbnhEkvF%akpm@linux-foundation.org> In-Reply-To: <20210628193256.008961950a714730751c1423@linux-foundation.org> User-Agent: s-nail v14.8.16 Authentication-Results: imf04.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=r9koi1Qw; spf=pass (imf04.hostedemail.com: domain of akpm@linux-foundation.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org; dmarc=none X-Stat-Signature: ybcjssqsxjs9rf4pi7ay8wcjdexw7t94 X-Rspamd-Queue-Id: 38CA6376 X-Rspamd-Server: rspam06 X-HE-Tag: 1624934472-70213 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: From: Aaron Tomlin Subject: mm/page_alloc: bail out on fatal signal during reclaim/compaction retry attempt A customer experienced a low-memory situation and decided to issue a SIGKILL (i.e. a fatal signal). Instead of promptly terminating as one would expect, the aforementioned task remained unresponsive. Further investigation indicated that the task was "stuck" in the reclaim/compaction retry loop. Now, it does not make sense to retry compaction when a fatal signal is pending. In the context of try_to_compact_pages(), indeed COMPACT_SKIPPED can be returned; albeit, not every zone, on the zone list, would be considered in the case a fatal signal is found to be pending. Yet, in should_compact_retry(), given the last known compaction result, each zone, on the zone list, can be considered/or checked (see compaction_zonelist_suitable()). For example, if a zone was found to succeed, then reclaim/compaction would be tried again (notwithstanding the above). This patch ensures that compaction is not needlessly retried irrespective of the last known compaction result e.g. if it was skipped, in the unlikely case a fatal signal is found pending. So, OOM is at least attempted. Link: https://lkml.kernel.org/r/20210520142901.3371299-1-atomlin@redhat.com Signed-off-by: Aaron Tomlin Reviewed-by: Vlastimil Babka Cc: Michal Hocko Cc: Matthew Wilcox Signed-off-by: Andrew Morton --- mm/page_alloc.c | 3 +++ 1 file changed, 3 insertions(+) --- a/mm/page_alloc.c~mm-page_alloc-bail-out-on-fatal-signal-during-reclaim-compaction-retry-attempt +++ a/mm/page_alloc.c @@ -4251,6 +4251,9 @@ should_compact_retry(struct alloc_contex if (!order) return false; + if (fatal_signal_pending(current)) + return false; + if (compaction_made_progress(compact_result)) (*compaction_retries)++;