From patchwork Mon Dec 16 12:45:23 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: SeongJae Park X-Patchwork-Id: 11294127 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 0EEF86C1 for ; Mon, 16 Dec 2019 12:47:07 +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 DE525206D3 for ; Mon, 16 Dec 2019 12:47:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="okF9f76X" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DE525206D3 Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=amazon.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 1igplI-0005Lt-Db; Mon, 16 Dec 2019 12:46:08 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1igplG-0005Lm-OT for xen-devel@lists.xenproject.org; Mon, 16 Dec 2019 12:46:06 +0000 X-Inumbo-ID: 0644a1ec-2002-11ea-b6f1-bc764e2007e4 Received: from smtp-fw-9101.amazon.com (unknown [207.171.184.25]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 0644a1ec-2002-11ea-b6f1-bc764e2007e4; Mon, 16 Dec 2019 12:46:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1576500367; x=1608036367; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=0TW+o5Tgcs6YL5BI1CJRd6ZjweSFLCGnKAQUOI6Qjb0=; b=okF9f76XPb3SOBdm0es33je0b2/83AmGs1uZf8QmyhFFJn+mppWR/i+6 V9m47fEmnz1beRfEt3FJxZAx+uJZxHloW+vRdZWDNBtDJI6nyQqYH1Bqm u+L02g7CIko0TybEhqvejQUgiNKGpQ/KzZ8yet3rB5i/1sLMPIUSx5x9V A=; IronPort-SDR: lj6VwkfMU5+vujBCYNe8M0EkLAMbAbxNEROEWrv98vwjyBBAwdR/cg6O5MdIo+qZudJuDWYh1d ziFbA4gV2uVw== X-IronPort-AV: E=Sophos;i="5.69,321,1571702400"; d="scan'208";a="5354767" Received: from sea32-co-svc-lb4-vlan3.sea.corp.amazon.com (HELO email-inbound-relay-2a-538b0bfb.us-west-2.amazon.com) ([10.47.23.38]) by smtp-border-fw-out-9101.sea19.amazon.com with ESMTP; 16 Dec 2019 12:45:55 +0000 Received: from EX13MTAUEA001.ant.amazon.com (pdx4-ws-svc-p6-lb7-vlan3.pdx.amazon.com [10.170.41.166]) by email-inbound-relay-2a-538b0bfb.us-west-2.amazon.com (Postfix) with ESMTPS id 4CBE5A25D6; Mon, 16 Dec 2019 12:45:54 +0000 (UTC) Received: from EX13D31EUA001.ant.amazon.com (10.43.165.15) by EX13MTAUEA001.ant.amazon.com (10.43.61.243) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Mon, 16 Dec 2019 12:45:53 +0000 Received: from u886c93fd17d25d.ant.amazon.com (10.43.160.100) by EX13D31EUA001.ant.amazon.com (10.43.165.15) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Mon, 16 Dec 2019 12:45:49 +0000 From: SeongJae Park To: , , , Date: Mon, 16 Dec 2019 13:45:23 +0100 Message-ID: <20191216124527.30306-1-sjpark@amazon.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 X-Originating-IP: [10.43.160.100] X-ClientProxiedBy: EX13D17UWC002.ant.amazon.com (10.43.162.61) To EX13D31EUA001.ant.amazon.com (10.43.165.15) Precedence: Bulk Subject: [Xen-devel] [PATCH v10 0/4] xenbus/backend: Add a memory pressure handler callback X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: linux-block@vger.kernel.org, SeongJae Park , pdurrant@amazon.com, 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 and fourth patches are trivial cleanups. 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_v10 Patch History ------------- Changes from v9 (https://lore.kernel.org/xen-devel/20191213153546.17425-1-sjpark@amazon.de/) - Add 'Reviewed-by' and 'Acked-by' from Roger Pau Monné - Update the commit message for overhead test of the 2nd path 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(-)