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=-8.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 3B07BC33CA8 for ; Mon, 13 Jan 2020 09:50:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 01D222075B for ; Mon, 13 Jan 2020 09:50:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="Jkmp4Ubf" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726109AbgAMJuV (ORCPT ); Mon, 13 Jan 2020 04:50:21 -0500 Received: from smtp-fw-4101.amazon.com ([72.21.198.25]:7301 "EHLO smtp-fw-4101.amazon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725992AbgAMJuV (ORCPT ); Mon, 13 Jan 2020 04:50:21 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1578909020; x=1610445020; h=from:to:cc:subject:date:message-id:mime-version: in-reply-to:content-transfer-encoding; bh=PX1ZrZhA4CFfySGOi+tectq1AtVISPobj3q9mu2po2A=; b=Jkmp4Ubfn4RWKqT1+45vPVd296IKOSShWLxagHEoflHm9yXpRVwkdzQP 0pWu0WonTsnlJOmOHWvSGdDwUUHy+Lrj4e75lI5o/0TOFH5cP+/hUImxZ FwhdTtAGCrhodnLVVaTB7AdbVPMXctAEZVjZP7YuGUjkiP6l960d8k/tY k=; IronPort-SDR: SVAJwSqTvIC1cetRulnIw53zATgp+qtYMK4EOT5etiQow4u9t9ZNP8jyw4WBe0jb4aiDkBN7PC R+Cf6N16IMRA== X-IronPort-AV: E=Sophos;i="5.69,428,1571702400"; d="scan'208";a="12077553" Received: from iad12-co-svc-p1-lb1-vlan3.amazon.com (HELO email-inbound-relay-1a-67b371d8.us-east-1.amazon.com) ([10.43.8.6]) by smtp-border-fw-out-4101.iad4.amazon.com with ESMTP; 13 Jan 2020 09:50:19 +0000 Received: from EX13MTAUEA002.ant.amazon.com (iad55-ws-svc-p15-lb9-vlan3.iad.amazon.com [10.40.159.166]) by email-inbound-relay-1a-67b371d8.us-east-1.amazon.com (Postfix) with ESMTPS id DFF64A2B27; Mon, 13 Jan 2020 09:50:16 +0000 (UTC) Received: from EX13D31EUA001.ant.amazon.com (10.43.165.15) by EX13MTAUEA002.ant.amazon.com (10.43.61.77) with Microsoft SMTP Server (TLS) id 15.0.1236.3; Mon, 13 Jan 2020 09:50:16 +0000 Received: from u886c93fd17d25d.ant.amazon.com (10.43.160.92) by EX13D31EUA001.ant.amazon.com (10.43.165.15) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Mon, 13 Jan 2020 09:50:11 +0000 From: SeongJae Park To: SeongJae Park CC: , , , , , , , , Subject: Re: [Xen-devel] [PATCH v13 0/5] xenbus/backend: Add memory pressure handler callback Date: Mon, 13 Jan 2020 10:49:52 +0100 Message-ID: <20200113094952.30727-1-sjpark@amazon.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 In-Reply-To: <20191218183718.31719-1-sjpark@amazon.com> (raw) Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit X-Originating-IP: [10.43.160.92] X-ClientProxiedBy: EX13D27UWA001.ant.amazon.com (10.43.160.19) To EX13D31EUA001.ant.amazon.com (10.43.165.15) Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Every patch of this patchset got at least one 'Reviewed-by' or 'Acked-by' from appropriate maintainers by last Wednesday, and after that, got no comment yet. May I ask some more comments? Thanks, SeongJae Park On Wed, 18 Dec 2019 19:37:13 +0100 SeongJae Park wrote: > 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 then introduce a lock for race > condition avoidance (patch 2). After that, patch 3 applies the callback > mechanism to mitigate the problem in 'xen-blkback'. The fourth and > fifth patches are trivial cleanups; those fix nits we found during the > development of this patchset. > > Note that patches 1, 4, and 5 are not changed since v9. > > > 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/patches/blkback/buffer_squeeze/v13 > > > Patch History > ------------- > > Changes from v12 > (https://lore.kernel.org/xen-devel/20191218104232.9606-1-sjpark@amazon.com/) > - Do not unnecessarily disable interrupts (suggested by Juergen) > - Hold lock from xenbus side (suggested by Juergen) > > Changes from v11 > (https://lore.kernel.org/xen-devel/20191217160748.693-2-sjpark@amazon.com/) > - Fix wrong trylock use (reported by Juergen) > - Merge patch 3 and 4 (suggested by Juergen) > - Update test result > > Changes from v10 > (https://lore.kernel.org/xen-devel/20191216124527.30306-1-sjpark@amazon.com/) > - Fix race condition (reported by SeongJae, suggested by Juergen) > > 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 (5): > xenbus/backend: Add memory pressure handler callback > xenbus/backend: Protect xenbus callback with lock > 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 | 28 ++++++++++--- > drivers/xen/xenbus/xenbus_probe.c | 8 +++- > drivers/xen/xenbus/xenbus_probe_backend.c | 38 +++++++++++++++++ > include/xen/xenbus.h | 3 ++ > 7 files changed, 103 insertions(+), 27 deletions(-) > > -- > 2.17.1 >