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 X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, UNPARSEABLE_RELAY,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 BFDA5C3F2C6 for ; Tue, 3 Mar 2020 16:29:10 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 066EF20838 for ; Tue, 3 Mar 2020 16:29:09 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 066EF20838 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 8B6586B0006; Tue, 3 Mar 2020 11:29:09 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 8643A6B0008; Tue, 3 Mar 2020 11:29:09 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 754126B000A; Tue, 3 Mar 2020 11:29:09 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0226.hostedemail.com [216.40.44.226]) by kanga.kvack.org (Postfix) with ESMTP id 5B0B46B0006 for ; Tue, 3 Mar 2020 11:29:09 -0500 (EST) Received: from smtpin24.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 2314B10F88 for ; Tue, 3 Mar 2020 16:29:09 +0000 (UTC) X-FDA: 76554585618.24.rub25_1c41d2741180f Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin24.hostedemail.com (Postfix) with ESMTP id 49FAC39B0A for ; Tue, 3 Mar 2020 16:16:38 +0000 (UTC) X-HE-Tag: rub25_1c41d2741180f X-Filterd-Recvd-Size: 2900 Received: from out30-42.freemail.mail.aliyun.com (out30-42.freemail.mail.aliyun.com [115.124.30.42]) by imf19.hostedemail.com (Postfix) with ESMTP for ; Tue, 3 Mar 2020 16:16:33 +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=e01f04452;MF=shile.zhang@linux.alibaba.com;NM=1;PH=DS;RN=6;SR=0;TI=SMTPD_---0TrZg1ZS_1583252154; Received: from e18g09479.et15sqa.tbsite.net(mailfrom:shile.zhang@linux.alibaba.com fp:SMTPD_---0TrZg1ZS_1583252154) by smtp.aliyun-inc.com(127.0.0.1); Wed, 04 Mar 2020 00:16:24 +0800 From: Shile Zhang To: Andrew Morton , Kirill Tkhai , Pavel Tatashin Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Shile Zhang Subject: [PATCH v2 1/1] mm: fix interrupt disabled long time inside deferred_init_memmap() Date: Wed, 4 Mar 2020 00:15:51 +0800 Message-Id: <20200303161551.132263-2-shile.zhang@linux.alibaba.com> X-Mailer: git-send-email 2.24.0.rc2 In-Reply-To: <20200303161551.132263-1-shile.zhang@linux.alibaba.com> References: <20200303161551.132263-1-shile.zhang@linux.alibaba.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable 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 'CONFIG_DEFERRED_STRUCT_PAGE_INIT' is set, 'pgdatinit' kthread will initialise the deferred pages with local interrupts disabled. It is introduced by commit 3a2d7fa8a3d5 ("mm: disable interrupts while initializing deferred pages"). The local interrupt will be disabled long time inside deferred_init_memmap(), depends on memory size. On machine with NCPUS <=3D 2, the 'pgdatinit' kthread could be pined on boot CPU, then the tick timer will stuck long time, which caused the system wall time inaccuracy. For example, the dmesg shown that: [ 0.197975] node 0 initialised, 32170688 pages in 1ms Obviously, 1ms is unreasonable. Now, fix it by restore in the pending interrupts inside the while loop. The reasonable demsg shown likes: [ 1.069306] node 0 initialised, 32203456 pages in 894ms Signed-off-by: Shile Zhang --- mm/page_alloc.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 3c4eb750a199..d3f337f2e089 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1809,8 +1809,12 @@ static int __init deferred_init_memmap(void *data) * that we can avoid introducing any issues with the buddy * allocator. */ - while (spfn < epfn) + while (spfn < epfn) { nr_pages +=3D deferred_init_maxorder(&i, zone, &spfn, &epfn); + /* let in any pending interrupts */ + local_irq_restore(flags); + local_irq_save(flags); + } zone_empty: pgdat_resize_unlock(pgdat, &flags); =20 --=20 2.24.0.rc2