From patchwork Mon Jul 22 09:36:08 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Konstantin Khlebnikov X-Patchwork-Id: 11051883 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 09B49112C for ; Mon, 22 Jul 2019 09:36:14 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E964226E4A for ; Mon, 22 Jul 2019 09:36:13 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id DCDCE285A3; Mon, 22 Jul 2019 09:36:13 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 54ECA26E4A for ; Mon, 22 Jul 2019 09:36:13 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 43CC56B000A; Mon, 22 Jul 2019 05:36:12 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 3EDA38E0001; Mon, 22 Jul 2019 05:36:12 -0400 (EDT) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 329E96B000D; Mon, 22 Jul 2019 05:36:12 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from mail-lf1-f70.google.com (mail-lf1-f70.google.com [209.85.167.70]) by kanga.kvack.org (Postfix) with ESMTP id C46166B000A for ; Mon, 22 Jul 2019 05:36:11 -0400 (EDT) Received: by mail-lf1-f70.google.com with SMTP id p9so3528673lfo.16 for ; Mon, 22 Jul 2019 02:36:11 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:dkim-signature:subject:from:to:cc:date :message-id:user-agent:mime-version:content-transfer-encoding; bh=DL5UzA+B5XRB4qh0F2iWC5P1iVbcg0/rElIhEVtbXfg=; b=ZakYmBXiNF4VWxl4IkPVdhH6ik3JBM2vwPzyvSah5rq+Gl6EkJUrn1xC7pY63Ksg0q wgElowHUki+sOAsOfW13gfjvINYHxERguHjj2wTpfiRVOOzfstZs51jBro8LmWX2M5a0 kMpvAOVIOiPHmLRel9nCg/4YaXXYVThvtXjGiAbJgr7Gi1qxYtNZle7LWipalVBZ0KZS RTT03H4nXDU6nN6T0T7UTVgNL817tVA+lcB6FqkJC1ghmqcQS34SCCbGYSUPBsAId+eV 6u1uUVyW9KwoVHRT0cJJ2htBb2zjBSNTgTKpr49fBekJL+8a+oUSEd2mos45fUaqN40K 1Tmw== X-Gm-Message-State: APjAAAUC535k5nzZTueztlyilS3rj7zCFNkubV15b1TFTFjfPa2RVfQ0 T6/kHobhWmaXomwBGFwckZjEl8SCvyZZz1OO1ps4j4h6LkRNJjdeA6vZoejGxs5ywhYsgQEDRou IHOXD3IA3NeAvwhdjo3Ch66TonWzFZ+Mschchmnvehaqf7L1KbdmJnymyyjJqum/Dvw== X-Received: by 2002:a2e:b0f0:: with SMTP id h16mr11773623ljl.21.1563788170981; Mon, 22 Jul 2019 02:36:10 -0700 (PDT) X-Google-Smtp-Source: APXvYqxKKPn9+VpjLb+PAEsfoizk2FhsF/nva3EhZBTRj3nkW9LyO8WmKsiLq1kBs2+XoA3vFwkw X-Received: by 2002:a2e:b0f0:: with SMTP id h16mr11773582ljl.21.1563788170235; Mon, 22 Jul 2019 02:36:10 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1563788170; cv=none; d=google.com; s=arc-20160816; b=A4MyiougDIQf0GkQk7impwfPXxI5/ZEaGJe0aHmftt4ii3qZANGH8VvmmFATuQuQgy EdPhk713lZBRcE3BgPuGFdbMMtQy2NlRr53cJj3E94pMDlge4HhMAPuDnGrq60jZWJvs o57xvOWQ6DFUP0MDa/swNoojI8VWdXzjHLu7VCjUr9wEnMRgv/jTEYImoPmxPOzJeav+ +BeMr8xC42v1RT5l0AulBxihho+mNcV1u/oMvwdlK12bOWtzOFYgcWSsJiNFu8inWdvv WeDbYgPJX8eGuN00DrQTD/qRa+UqGktY3h8o3zIFwsy8A06O0jcJiDmygDlPpU0kZ4sr 4y9w== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-transfer-encoding:mime-version:user-agent:message-id:date :cc:to:from:subject:dkim-signature; bh=DL5UzA+B5XRB4qh0F2iWC5P1iVbcg0/rElIhEVtbXfg=; b=ABC0KeZyD2Z2JhgkkvtO0tmiBd6Kh5pMjRg9dGabDQsJuyLPq4REw4RP27bTMG+2C4 dvpNupPNe8bqXtOc4b56MbozsIoMvnwT0rqFNKeGU7Sg7M4+/6lrF+vWEUF1N4jVF6a0 DEe16opJceY+ET/xFRD+15EI/1BMXPuS1qNnK40vK4ztFByraCmWvom0YZillVRQ675p mrmLFcKKr2hcHcGF0wBHVAmvnqnG7FtTWyXAQWAbYhTp49MStGorBZGhvCaVD1o9JmY+ GmBwBP9CzVnIfl+92dU35afTSL7WB/kycS1w3I0WTrN//lZjiY0W7jKngXiJu+1RmcVf X6tg== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@yandex-team.ru header.s=default header.b=C4FclbtD; spf=pass (google.com: domain of khlebnikov@yandex-team.ru designates 95.108.205.193 as permitted sender) smtp.mailfrom=khlebnikov@yandex-team.ru; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=yandex-team.ru Received: from forwardcorp1o.mail.yandex.net (forwardcorp1o.mail.yandex.net. [95.108.205.193]) by mx.google.com with ESMTPS id z4si30232701lfj.82.2019.07.22.02.36.10 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 22 Jul 2019 02:36:10 -0700 (PDT) Received-SPF: pass (google.com: domain of khlebnikov@yandex-team.ru designates 95.108.205.193 as permitted sender) client-ip=95.108.205.193; Authentication-Results: mx.google.com; dkim=pass header.i=@yandex-team.ru header.s=default header.b=C4FclbtD; spf=pass (google.com: domain of khlebnikov@yandex-team.ru designates 95.108.205.193 as permitted sender) smtp.mailfrom=khlebnikov@yandex-team.ru; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=yandex-team.ru Received: from mxbackcorp2j.mail.yandex.net (mxbackcorp2j.mail.yandex.net [IPv6:2a02:6b8:0:1619::119]) by forwardcorp1o.mail.yandex.net (Yandex) with ESMTP id 8EF252E1251; Mon, 22 Jul 2019 12:36:09 +0300 (MSK) Received: from smtpcorp1o.mail.yandex.net (smtpcorp1o.mail.yandex.net [2a02:6b8:0:1a2d::30]) by mxbackcorp2j.mail.yandex.net (nwsmtp/Yandex) with ESMTP id piK2rewsgT-a8Nmo53U; Mon, 22 Jul 2019 12:36:09 +0300 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yandex-team.ru; s=default; t=1563788169; bh=DL5UzA+B5XRB4qh0F2iWC5P1iVbcg0/rElIhEVtbXfg=; h=Message-ID:Date:To:From:Subject:Cc; b=C4FclbtDQ5b7smwavzXfTwnAGBDtyvoKz3qJxF/M76PisgHI1mGKIvG4cGohU069H I+8pkq99Gy18EG8atUE+4MtHJf7ZK+4vWOcIFCuhSSGHIaGhFtECkYzI0ajGXe82Ox ixtwBZaI7SGYRKn+koCY2zzBmM5SBCVGXhL8BdLI= Authentication-Results: mxbackcorp2j.mail.yandex.net; dkim=pass header.i=@yandex-team.ru Received: from dynamic-red.dhcp.yndx.net (dynamic-red.dhcp.yndx.net [2a02:6b8:0:40c:38b3:1cdf:ad1a:1fe1]) by smtpcorp1o.mail.yandex.net (nwsmtp/Yandex) with ESMTPSA id tCVKM0ss34-a8I48tMX; Mon, 22 Jul 2019 12:36:08 +0300 (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client certificate not present) Subject: [PATCH 1/2] mm/filemap: don't initiate writeback if mapping has no dirty pages From: Konstantin Khlebnikov To: linux-mm@kvack.org, Andrew Morton , linux-kernel@vger.kernel.org Cc: Tejun Heo , Jens Axboe , Johannes Weiner Date: Mon, 22 Jul 2019 12:36:08 +0300 Message-ID: <156378816804.1087.8607636317907921438.stgit@buzz> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 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: X-Virus-Scanned: ClamAV using ClamSMTP Functions like filemap_write_and_wait_range() should do nothing if inode has no dirty pages or pages currently under writeback. But they anyway construct struct writeback_control and this does some atomic operations if CONFIG_CGROUP_WRITEBACK=y - on fast path it locks inode->i_lock and updates state of writeback ownership, on slow path might be more work. Current this path is safely avoided only when inode mapping has no pages. For example generic_file_read_iter() calls filemap_write_and_wait_range() at each O_DIRECT read - pretty hot path. This patch skips starting new writeback if mapping has no dirty tags set. If writeback is already in progress filemap_write_and_wait_range() will wait for it. Signed-off-by: Konstantin Khlebnikov Reviewed-by: Jan Kara --- mm/filemap.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/mm/filemap.c b/mm/filemap.c index d0cf700bf201..d9572593e5c7 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -408,7 +408,8 @@ int __filemap_fdatawrite_range(struct address_space *mapping, loff_t start, .range_end = end, }; - if (!mapping_cap_writeback_dirty(mapping)) + if (!mapping_cap_writeback_dirty(mapping) || + !mapping_tagged(mapping, PAGECACHE_TAG_DIRTY)) return 0; wbc_attach_fdatawrite_inode(&wbc, mapping->host); From patchwork Mon Jul 22 09:36:10 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Konstantin Khlebnikov X-Patchwork-Id: 11051885 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 26AE5112C for ; Mon, 22 Jul 2019 09:36:16 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 153F021FAD for ; 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[77.88.29.217]) by mx.google.com with ESMTPS id u1si32893739ljk.164.2019.07.22.02.36.12 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 22 Jul 2019 02:36:12 -0700 (PDT) Received-SPF: pass (google.com: domain of khlebnikov@yandex-team.ru designates 77.88.29.217 as permitted sender) client-ip=77.88.29.217; Authentication-Results: mx.google.com; dkim=pass header.i=@yandex-team.ru header.s=default header.b=DIJf1MDR; spf=pass (google.com: domain of khlebnikov@yandex-team.ru designates 77.88.29.217 as permitted sender) smtp.mailfrom=khlebnikov@yandex-team.ru; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=yandex-team.ru Received: from mxbackcorp1j.mail.yandex.net (mxbackcorp1j.mail.yandex.net [IPv6:2a02:6b8:0:1619::162]) by forwardcorp1p.mail.yandex.net (Yandex) with ESMTP id 9F3E62E0DE0; Mon, 22 Jul 2019 12:36:11 +0300 (MSK) Received: from smtpcorp1j.mail.yandex.net (smtpcorp1j.mail.yandex.net [2a02:6b8:0:1619::137]) by mxbackcorp1j.mail.yandex.net (nwsmtp/Yandex) with ESMTP id j01G7HEpSm-aB5ajCCf; Mon, 22 Jul 2019 12:36:11 +0300 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yandex-team.ru; s=default; t=1563788171; bh=lwrou0ge1fASn3VFBYr42gXUSv9B+Mk8b6WwMg4i5lM=; h=In-Reply-To:Message-ID:References:Date:To:From:Subject:Cc; b=DIJf1MDRS9k2nQaZ1DgVQQtOdHcWYktPONyBemWBggu9EEvRAg6Ds8yKgaBx5Dv6W sGFFBF2U1e2JvDzUAUEP/9sFGmg5kQO55TsEkZv26H6df3OseRxvm+jBfIpXKmXZ3k kC14yyhFJf0AahFHsm9tMubKphNZg5HHcbYzOwtU= Authentication-Results: mxbackcorp1j.mail.yandex.net; dkim=pass header.i=@yandex-team.ru Received: from dynamic-red.dhcp.yndx.net (dynamic-red.dhcp.yndx.net [2a02:6b8:0:40c:38b3:1cdf:ad1a:1fe1]) by smtpcorp1j.mail.yandex.net (nwsmtp/Yandex) with ESMTPSA id AdNDBXcM8x-aBAq2o3D; Mon, 22 Jul 2019 12:36:11 +0300 (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client certificate not present) Subject: [PATCH 2/2] mm/filemap: rewrite mapping_needs_writeback in less fancy manner From: Konstantin Khlebnikov To: linux-mm@kvack.org, Andrew Morton , linux-kernel@vger.kernel.org Cc: Tejun Heo , Jens Axboe , Johannes Weiner Date: Mon, 22 Jul 2019 12:36:10 +0300 Message-ID: <156378817069.1087.1302816672037672488.stgit@buzz> In-Reply-To: <156378816804.1087.8607636317907921438.stgit@buzz> References: <156378816804.1087.8607636317907921438.stgit@buzz> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 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: X-Virus-Scanned: ClamAV using ClamSMTP This actually checks that writeback is needed or in progress. Signed-off-by: Konstantin Khlebnikov --- mm/filemap.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/mm/filemap.c b/mm/filemap.c index d9572593e5c7..29f503ffd70b 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -618,10 +618,13 @@ int filemap_fdatawait_keep_errors(struct address_space *mapping) } EXPORT_SYMBOL(filemap_fdatawait_keep_errors); +/* Returns true if writeback might be needed or already in progress. */ static bool mapping_needs_writeback(struct address_space *mapping) { - return (!dax_mapping(mapping) && mapping->nrpages) || - (dax_mapping(mapping) && mapping->nrexceptional); + if (dax_mapping(mapping)) + return mapping->nrexceptional; + + return mapping->nrpages; } int filemap_write_and_wait(struct address_space *mapping)