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=-10.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 37180C433E0 for ; Mon, 1 Mar 2021 15:35:36 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id B8DF664DDE for ; Mon, 1 Mar 2021 15:35:35 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B8DF664DDE Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=nvidia.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 18BE28D007C; Mon, 1 Mar 2021 10:35:35 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 13C6E8D0063; Mon, 1 Mar 2021 10:35:35 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 052388D007C; Mon, 1 Mar 2021 10:35:35 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0194.hostedemail.com [216.40.44.194]) by kanga.kvack.org (Postfix) with ESMTP id E5AC28D0063 for ; Mon, 1 Mar 2021 10:35:34 -0500 (EST) Received: from smtpin25.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id AC1CA7599 for ; Mon, 1 Mar 2021 15:35:34 +0000 (UTC) X-FDA: 77871704988.25.FE3379C Received: from hqnvemgate25.nvidia.com (hqnvemgate25.nvidia.com [216.228.121.64]) by imf06.hostedemail.com (Postfix) with ESMTP id AEFA0C0007FE for ; Mon, 1 Mar 2021 15:35:31 +0000 (UTC) Received: from hqmail.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate25.nvidia.com (using TLS: TLSv1.2, AES256-SHA) id ; Mon, 01 Mar 2021 07:35:26 -0800 Received: from [10.2.62.13] (172.20.145.6) by HQMAIL107.nvidia.com (172.20.187.13) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Mon, 1 Mar 2021 15:35:24 +0000 From: Zi Yan To: David Hildenbrand CC: , , Andrew Morton , Minchan Kim , Oscar Salvador , Michal Hocko , Vlastimil Babka Subject: Re: [PATCH v1] mm/page_alloc: drop pr_info_ratelimited() in alloc_contig_range() Date: Mon, 1 Mar 2021 10:35:22 -0500 X-Mailer: MailMate (1.14r5757) Message-ID: <395622C6-F8D9-408D-B35B-17B16F1B5E77@nvidia.com> In-Reply-To: <20210301150945.77012-1-david@redhat.com> References: <20210301150945.77012-1-david@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="=_MailMate_4DE8FF03-D3CA-4DB3-A579-7B9830E8D138_="; micalg=pgp-sha512; protocol="application/pgp-signature" X-Originating-IP: [172.20.145.6] X-ClientProxiedBy: HQMAIL111.nvidia.com (172.20.187.18) To HQMAIL107.nvidia.com (172.20.187.13) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1614612926; bh=mlhQ908O+sCee8WIaVYPJGEGthrRsdrP1NwFa/Q04FY=; h=From:To:CC:Subject:Date:X-Mailer:Message-ID:In-Reply-To: References:MIME-Version:Content-Type:X-Originating-IP: X-ClientProxiedBy; b=ONrAPlJIRGAQDmRsAIAmwk4l1cJfSksrX9LPBzg7hsJw8fGVVkME8LcwEqO09USX+ rmkOWP67PLZQT8XZoNIa7q5d1uZ2pGvBw0RonplPNF4bo0fwC3rZu81HWOafmv0z/x 96m9FMU8H9N3JMACInbdZ2J8kzJKYa9AnwuCwoOKcOrtEbKcpIRkLMF3CahxxOv2jw Lo9W2aAqSYVtSSXjpLTa5CSpj6JV+cdvGwxhpOwQFvdhMILrkPx3MljClnWdMSe4VA 3BfzEl8DGiXgSnfyhQfJMXZiGMhRhXxTs+4jrjGLwdBQXzfTzeKOhDxsu5VIvmmojN LTumdxfOTZTwA== X-Stat-Signature: 5u9h4r751eefuwpx6yqu8oh6my6amakm X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: AEFA0C0007FE Received-SPF: none (nvidia.com>: No applicable sender policy available) receiver=imf06; identity=mailfrom; envelope-from=""; helo=hqnvemgate25.nvidia.com; client-ip=216.228.121.64 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1614612931-713236 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: --=_MailMate_4DE8FF03-D3CA-4DB3-A579-7B9830E8D138_= Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On 1 Mar 2021, at 10:09, David Hildenbrand wrote: > The information that some PFNs are busy is: > a) not helpful for ordinary users: we don't even know *who* called > alloc_contig_range(). This is certainly not worth a pr_info.*(). > b) not really helpful for debugging: we don't have any details *why* > these PFNs are busy, and that is what we usually care about. > c) not complete: there are other cases where we fail alloc_contig_range= () > using different paths that are not getting recorded. > > For example, we reach this path once we succeeded in isolating pagebloc= ks, > but failed to migrate some pages - which can happen easily on > ZONE_NORMAL (i.e., has_unmovable_pages() is racy) but also on ZONE_MOVA= BLE > i.e., we would have to retry longer to migrate). > > For example via virtio-mem when unplugging memory, we can create quite > some noise (especially with ZONE_NORMAL) that is not of interest to > users - it's expected that some allocations may fail as memory is busy.= > > Let's just drop that pr_info_ratelimit() and rather implement a dynamic= > debugging mechanism in the future that can give us a better reason why > alloc_contig_range() failed on specific pages. > > Cc: Andrew Morton > Cc: Minchan Kim > Cc: Oscar Salvador > Cc: Michal Hocko > Cc: Vlastimil Babka > Signed-off-by: David Hildenbrand > --- LGTM. I agree that the printout is not quite useful. Reviewed-by: Zi Yan =E2=80=94 Best Regards, Yan Zi --=_MailMate_4DE8FF03-D3CA-4DB3-A579-7B9830E8D138_= Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQJDBAEBCgAtFiEEh7yFAW3gwjwQ4C9anbJR82th+ooFAmA9CbsPHHppeUBudmlk aWEuY29tAAoJEJ2yUfNrYfqKyb4P/1ha6j2AhTzE2u9SupGjtogS2/KnuQ1BZbia BCSikFAaAVEV17Fdm3VdajT0TKCzQCPM5xKO+PDfWyjhfeyNruvnFkISz4LmJV2R lvHTLnl2JYeEA5rJfXvu8pIJJxci/QkngYvR0yViM2P0y2mfs8+Bfz+1Z2MaQ4l+ U6yOFGQURlcuMlbFaLdU2/7qZOb2bzR0iqpvF5AuY+sK0KzpF1yL/bFKYY72KqAJ 6CZY+nID2Cn6J59qfHTX1+BLtqzn1FTjuQ+poMmRTijd31x6K/DbPidjJYNXE+qG uRwz31V4gAdflEypY5xmTKJAQp5v30FdHhINIP+KTTDnVzD9Dlfw8+tQhPFFNFv8 Lnv+Cxx/z9xAAMLmIiZ3TWpru0dNjbRd/XYlg1FViKJwKRNVGpgCuT7BgYiT148j EGHPJVgICkXgPX0ADwKRlQ/W9xEn+M622IeLHsACGQzYyJoi3XegHBQhBDNkUpFv EdTBF01KFvgJd3CQv8gVL7UZU97dll37Ef2JYGD8MsrruCCcriQn3zs0MtX/VkYn ZkubLroJ+nbZVaFtihp1Sl1I5/qrV0jna/8IUG7wsXxrZMOefV6Suu1FYmqdLQ+D gvoHHT9v+oogh727Inpv6vcQwzvJ4dCF2dYOlE2tYoEJPCT4YvmGS3mIp/sQq/NE w+FIx5Nf =DMSI -----END PGP SIGNATURE----- --=_MailMate_4DE8FF03-D3CA-4DB3-A579-7B9830E8D138_=--