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=-3.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 506B8C46470 for ; Wed, 8 Aug 2018 14:26:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 02426219C9 for ; Wed, 8 Aug 2018 14:26:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 02426219C9 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727496AbeHHQpl (ORCPT ); Wed, 8 Aug 2018 12:45:41 -0400 Received: from mx2.suse.de ([195.135.220.15]:55176 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727177AbeHHQpk (ORCPT ); Wed, 8 Aug 2018 12:45:40 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id D18B5AE15; Wed, 8 Aug 2018 14:25:45 +0000 (UTC) From: Juergen Gross To: linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org, linux-block@vger.kernel.org Cc: konrad.wilk@oracle.com, roger.pau@citrix.com, axboe@kernel.dk, boris.ostrovsky@oracle.com, Juergen Gross Subject: [PATCH v2 0/5] xen/blk: persistent grant rework Date: Wed, 8 Aug 2018 16:25:23 +0200 Message-Id: <20180808142528.31029-1-jgross@suse.com> X-Mailer: git-send-email 2.13.7 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Persistent grants are used in the Xen's blkfront/blkback drivers to avoid mapping/unmapping of I/O buffers in the backend for each I/O. While this speeds up processing quite a bit there are problems related to persistent grants in some configurations: domains with multiple block devices making use of persistent grants might suffer from a lack of grants if each of the block devices experienced a high I/O load at some time. This is due to the number of persistent grants per device only to be limited by a rather high maximum value, but never being released even in case of longer times without any I/O. This series modifies xen-blkback to unmap any domU page mapped via a persistent grant after a timeout (default: 60 seconds). The timeout is set to its default value again when a persistent grant has been used for an I/O. xen-blkfront is modified to scan every 10 seconds for persistent grants not in use by blkback any more and to remove such grants. The last 3 patches are small cleanups of blkfront and blkback drivers. V2: - patch 1: added new module parameter doc - patch 1: removed PERSISTENT_GNT_WAS_ACTIVE flag - patch 2: removed global worker active flag - added new patch 4 Juergen Gross (5): xen/blkback: don't keep persistent grants too long xen/blkfront: cleanup stale persistent grants xen/blkfront: reorder tests in xlblk_init() xen/blkback: move persistent grants flags to bool xen/blkback: remove unused pers_gnts_lock from struct xen_blkif_ring Documentation/ABI/testing/sysfs-driver-xen-blkback | 10 ++ drivers/block/xen-blkback/blkback.c | 99 ++++++++++--------- drivers/block/xen-blkback/common.h | 14 +-- drivers/block/xen-blkfront.c | 110 ++++++++++++++++++--- 4 files changed, 163 insertions(+), 70 deletions(-) -- 2.13.7