From patchwork Fri Dec 13 15:35:42 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: SeongJae Park X-Patchwork-Id: 11291139 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id EEA836C1 for ; Fri, 13 Dec 2019 21:00:32 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id BF34D24682 for ; Fri, 13 Dec 2019 21:00:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="oWjJ6SPo" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BF34D24682 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1ifmz6-0002zs-Uq; Fri, 13 Dec 2019 15:36:04 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1ifmz6-0002zm-4i for xen-devel@lists.xenproject.org; Fri, 13 Dec 2019 15:36:04 +0000 X-Inumbo-ID: 44dbb8e6-1dbe-11ea-88e7-bc764e2007e4 Received: from mail-pf1-x442.google.com (unknown [2607:f8b0:4864:20::442]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 44dbb8e6-1dbe-11ea-88e7-bc764e2007e4; Fri, 13 Dec 2019 15:36:02 +0000 (UTC) Received: by mail-pf1-x442.google.com with SMTP id 4so1647046pfz.9 for ; Fri, 13 Dec 2019 07:36:02 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=z8JrPILmBNkuXmgh0CCRqTuGd1v6Ben6NRIYOOVYH2k=; b=oWjJ6SPormw/9aWlYAqMt0mWZxPQ/qNu7pEFrAaJhnWJ+GoTw/ZcIvbNrmZyihzCkf piyjbLAzqCzZKol0+U+KNPcroPZ39r1GHMH+f84jFUBfEzbNdiiaR3bhB23LiITOp/Zf AKE4VWpiRGOngO9qA8lIgvW8cYCVzJi27ripb4euNsHN1DOwI/z2o7Xj7zT7fneiHAFD v1V8PSNnVohEa3zIrzCxJKvCd6RZ6hQZ3D+GxfbL7sMVYjh7vC95x+PavfXmAoMDbDAX CCodyR5SRkgXQE75t9YNsiD6x+XGUAZCBU3QX892DfRtwjphqSqr73jl6lC42jabK3Jo +BRA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=z8JrPILmBNkuXmgh0CCRqTuGd1v6Ben6NRIYOOVYH2k=; b=tCfHrwU2r0bczliWgn6bFVB2U3TIvdDGx1xihQQnFXD2xSvUCZLtGOh/YrStcquCfG Ral1o9Jk/1Osek0YThMmzhAUJR0H0eVfdTgLRHampLaolBkNP0rQirYRCdBP2nHE32VA u5+k5uNGME1Xz/VRVHIr+KCDh04f7ySe2Ct0zFzb1zofMPU962hP14mOdGcGEiJ2xrlx yhprm8DWz9rzYQs/3qk6bVfRpVHjQfyDTm7lIvIfrLCXMdSb5IQ18TI53hxbxaA48U0N qU5G+cSnzdQ86O01jXLBAe4Cf295SlzSPiTk/XV8Do90G51UYBUatmzcxSxFdfs47bHm EyQw== X-Gm-Message-State: APjAAAU9LpENTS1OcSzuHCkUCEXUQJjtAvWkA7cmNklWmogpLYV4vnzT NswxwVfeSMaeUQp/GKpodng= X-Google-Smtp-Source: APXvYqy2mR1RAyt47UgDW+/8fahahEZ/8xauJw9MRhkmZdtownWeUeLWxCGXBe/tAu3OBjOgx2U/Hw== X-Received: by 2002:a65:590f:: with SMTP id f15mr17211719pgu.381.1576251361836; Fri, 13 Dec 2019 07:36:01 -0800 (PST) Received: from localhost.localdomain ([12.176.148.120]) by smtp.gmail.com with ESMTPSA id w131sm12039217pfc.16.2019.12.13.07.36.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 13 Dec 2019 07:36:01 -0800 (PST) From: SeongJae Park X-Google-Original-From: SeongJae Park To: jgross@suse.com, axboe@kernel.dk, konrad.wilk@oracle.com, roger.pau@citrix.com Date: Fri, 13 Dec 2019 15:35:42 +0000 Message-Id: <20191213153546.17425-1-sjpark@amazon.de> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 Subject: [Xen-devel] [PATCH v9 0/4] xenbus/backend: Add a memory pressure handler callback X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: linux-block@vger.kernel.org, sjpark@amazon.com, pdurrant@amazon.com, SeongJae Park , linux-kernel@vger.kernel.org, sj38.park@gmail.com, xen-devel@lists.xenproject.org Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" Granting pages consumes backend system memory. In systems configured with insufficient spare memory for those pages, it can cause a memory pressure situation. However, finding the optimal amount of the spare memory is challenging for large systems having dynamic resource utilization patterns. Also, such a static configuration might lack flexibility. To mitigate such problems, this patchset adds a memory reclaim callback to 'xenbus_driver' (patch 1) and use it to mitigate the problem in 'xen-blkback' (patch 2). The third patch is a trivial cleanup of variable names. Base Version ------------ This patch is based on v5.4. A complete tree is also available at my public git repo: https://github.com/sjp38/linux/tree/blkback_squeezing_v9 Patch History ------------- Changes from v8 (https://lore.kernel.org/xen-devel/20191213130211.24011-1-sjpark@amazon.de/) - Drop 'Reviewed-by: Juergen' from the second patch (suggested by Roger Pau Monné) - Update contact of the new module param to SeongJae Park (suggested by Roger Pau Monné) - Wordsmith the description of the parameter (suggested by Roger Pau Monné) - Fix dumb bugs (suggested by Roger Pau Monné) - Move module param definition to xenbus.c and reduce the number of lines for this change (suggested by Roger Pau Monné) - Add a comment for the new callback, reclaim_memory, as other callbacks also have - Add another trivial cleanup of xenbus.c file (4th patch) Changes from v7 (https://lore.kernel.org/xen-devel/20191211181016.14366-1-sjpark@amazon.de/) - Update sysfs-driver-xen-blkback for new parameter (suggested by Roger Pau Monné) - Use per-xen_blkif buffer_squeeze_end instead of global variable (suggested by Roger Pau Monné) Changes from v6 (https://lore.kernel.org/linux-block/20191211042428.5961-1-sjpark@amazon.de/) - Remove more unnecessary prefixes (suggested by Roger Pau Monné) - Constify a variable (suggested by Roger Pau Monné) - Rename 'reclaim' into 'reclaim_memory' (suggested by Roger Pau Monné) - More wordsmith of the commit message (suggested by Roger Pau Monné) Changes from v5 (https://lore.kernel.org/linux-block/20191210080628.5264-1-sjpark@amazon.de/) - Wordsmith the commit messages (suggested by Roger Pau Monné) - Change the reclaim callback return type (suggested by Roger Pau Monné) - Change the type of the blkback squeeze duration variable (suggested by Roger Pau Monné) - Add a patch for removal of unnecessary static variable name prefixes (suggested by Roger Pau Monné) - Fix checkpatch.pl warnings Changes from v4 (https://lore.kernel.org/xen-devel/20191209194305.20828-1-sjpark@amazon.com/) - Remove domain id parameter from the callback (suggested by Juergen Gross) - Rename xen-blkback module parameter (suggested by Stefan Nuernburger) Changes from v3 (https://lore.kernel.org/xen-devel/20191209085839.21215-1-sjpark@amazon.com/) - Add general callback in xen_driver and use it (suggested by Juergen Gross) Changes from v2 (https://lore.kernel.org/linux-block/af195033-23d5-38ed-b73b-f6e2e3b34541@amazon.com) - Rename the module parameter and variables for brevity (aggressive shrinking -> squeezing) Changes from v1 (https://lore.kernel.org/xen-devel/20191204113419.2298-1-sjpark@amazon.com/) - Adjust the description to not use the term, `arbitrarily` (suggested by Paul Durrant) - Specify time unit of the duration in the parameter description, (suggested by Maximilian Heyne) - Change default aggressive shrinking duration from 1ms to 10ms - Merge two patches into one single patch SeongJae Park (4): xenbus/backend: Add memory pressure handler callback xen/blkback: Squeeze page pools if a memory pressure is detected xen/blkback: Remove unnecessary static variable name prefixes xen/blkback: Consistently insert one empty line between functions .../ABI/testing/sysfs-driver-xen-blkback | 10 +++++ drivers/block/xen-blkback/blkback.c | 42 +++++++++---------- drivers/block/xen-blkback/common.h | 1 + drivers/block/xen-blkback/xenbus.c | 26 +++++++++--- drivers/xen/xenbus/xenbus_probe_backend.c | 32 ++++++++++++++ include/xen/xenbus.h | 1 + 6 files changed, 86 insertions(+), 26 deletions(-)