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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6543ECCA47C for ; Tue, 7 Jun 2022 19:18:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1351397AbiFGTSV (ORCPT ); Tue, 7 Jun 2022 15:18:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55124 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1355482AbiFGTQC (ORCPT ); Tue, 7 Jun 2022 15:16:02 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5A533196A9F; Tue, 7 Jun 2022 11:07:46 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id AC3EFB82349; Tue, 7 Jun 2022 18:07:31 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D65F4C385A5; Tue, 7 Jun 2022 18:07:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1654625250; bh=NC3/9I5CrW1I+k0hMZefr0X4gn8kFk31fzUXfvgDPhw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=zCk0Vh9R7yamtX87PYSauQ2MmPvuUB0tR7uAy7LWkFY4lOJjBh7yIlUq9t8u5bcty pw/0YkYwj0dLhU8zWhTWyiC2qgj+34U4pUeWnh0Br5KrPKFIgCVnmM1qRqwAC0OllU wE9sjEoSt9lf2gkvsi2uO2vE2P7rhf4pmQheAYK8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Mel Gorman , "Darrick J. Wong" , Dave Chinner , Jan Kara , Vlastimil Babka , Jesper Dangaard Brouer , Chuck Lever , Andrew Morton Subject: [PATCH 5.15 620/667] mm/page_alloc: always attempt to allocate at least one page during bulk allocation Date: Tue, 7 Jun 2022 19:04:45 +0200 Message-Id: <20220607164953.265458711@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220607164934.766888869@linuxfoundation.org> References: <20220607164934.766888869@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Mel Gorman commit c572e4888ad1be123c1516ec577ad30a700bbec4 upstream. Peter Pavlisko reported the following problem on kernel bugzilla 216007. When I try to extract an uncompressed tar archive (2.6 milion files, 760.3 GiB in size) on newly created (empty) XFS file system, after first low tens of gigabytes extracted the process hangs in iowait indefinitely. One CPU core is 100% occupied with iowait, the other CPU core is idle (on 2-core Intel Celeron G1610T). It was bisected to c9fa563072e1 ("xfs: use alloc_pages_bulk_array() for buffers") but XFS is only the messenger. The problem is that nothing is waking kswapd to reclaim some pages at a time the PCP lists cannot be refilled until some reclaim happens. The bulk allocator checks that there are some pages in the array and the original intent was that a bulk allocator did not necessarily need all the requested pages and it was best to return as quickly as possible. This was fine for the first user of the API but both NFS and XFS require the requested number of pages be available before making progress. Both could be adjusted to call the page allocator directly if a bulk allocation fails but it puts a burden on users of the API. Adjust the semantics to attempt at least one allocation via __alloc_pages() before returning so kswapd is woken if necessary. It was reported via bugzilla that the patch addressed the problem and that the tar extraction completed successfully. This may also address bug 215975 but has yet to be confirmed. BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=216007 BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=215975 Link: https://lkml.kernel.org/r/20220526091210.GC3441@techsingularity.net Fixes: 387ba26fb1cb ("mm/page_alloc: add a bulk page allocator") Signed-off-by: Mel Gorman Cc: "Darrick J. Wong" Cc: Dave Chinner Cc: Jan Kara Cc: Vlastimil Babka Cc: Jesper Dangaard Brouer Cc: Chuck Lever Cc: [5.13+] Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- mm/page_alloc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -5299,8 +5299,8 @@ unsigned long __alloc_pages_bulk(gfp_t g page = __rmqueue_pcplist(zone, 0, ac.migratetype, alloc_flags, pcp, pcp_list); if (unlikely(!page)) { - /* Try and get at least one page */ - if (!nr_populated) + /* Try and allocate at least one page */ + if (!nr_account) goto failed_irq; break; }