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=-8.8 required=3.0 tests=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 6AE11C433FF for ; Tue, 30 Jul 2019 14:21:12 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (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 414CA20659 for ; Tue, 30 Jul 2019 14:21:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 414CA20659 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=virtuozzo.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:33434 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hsT03-0006mQ-D9 for qemu-devel@archiver.kernel.org; Tue, 30 Jul 2019 10:21:11 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:59355) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hsSxV-0002II-HR for qemu-devel@nongnu.org; Tue, 30 Jul 2019 10:18:34 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hsSxT-0002hq-NV for qemu-devel@nongnu.org; Tue, 30 Jul 2019 10:18:33 -0400 Received: from relay.sw.ru ([185.231.240.75]:49364) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hsSxT-0002gA-FE; Tue, 30 Jul 2019 10:18:31 -0400 Received: from [10.94.3.0] (helo=kvm.qa.sw.ru) by relay.sw.ru with esmtp (Exim 4.92) (envelope-from ) id 1hsSxP-0000jQ-EM; Tue, 30 Jul 2019 17:18:27 +0300 From: Vladimir Sementsov-Ogievskiy To: qemu-devel@nongnu.org, qemu-block@nongnu.org Date: Tue, 30 Jul 2019 17:18:22 +0300 Message-Id: <20190730141826.709849-1-vsementsov@virtuozzo.com> X-Mailer: git-send-email 2.18.0 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 185.231.240.75 Subject: [Qemu-devel] [PATCH v2 0/4] qcow2: async handling of fragmented io X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, vsementsov@virtuozzo.com, armbru@redhat.com, mreitz@redhat.com, stefanha@redhat.com, den@openvz.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Hi all! Here is an asynchronous scheme for handling fragmented qcow2 reads and writes. Both qcow2 read and write functions loops through sequential portions of data. The series aim it to parallelize these loops iterations. It improves performance for fragmented qcow2 images, I've tested it as described below. v2: changed a lot, as 1. a lot of preparations around locks, hd_qiovs, threads for encryption are done 2. I decided to create separate file with async request handling API, to reuse it for backup, stream and copy-on-read to improve their performance too. Mirror and qemu-img convert has their own async request handling, may be we'll be able finally merge all these similar code into one feature. Note that not all API calls used in qcow2, some will be needed on following steps for parallelizing other io loops. Based-on: https://github.com/stefanha/qemu/commits/block About testing: I have four 4G qcow2 images (with default 64k block size) on my ssd disk: t-seq.qcow2 - sequentially written qcow2 image t-reverse.qcow2 - filled by writing 64k portions from end to the start t-rand.qcow2 - filled by writing 64k portions (aligned) in random order t-part-rand.qcow2 - filled by shuffling order of 64k writes in 1m clusters (see source code of image generation in the end for details) and I've done several runs like the following (sequential io by 1mb chunks): out=/tmp/block; echo > $out; cat /tmp/files | while read file; do for wr in {"","-w"}; do echo "$file" $wr; ./qemu-img bench -c 4096 -d 1 -f qcow2 -n -s 1m -t none $wr "$file" | grep 'Run completed in' | awk '{print $4}' >> $out; done; done short info about parameters: -w - do writes (otherwise do reads) -c - count of blocks -s - block size -t none - disable cache -n - native aio -d 1 - don't use parallel requests provided by qemu-img bench itself results: +---------------------------+---------+---------+ | file | master | async | +---------------------------+---------+---------+ | /ssd/t-part-rand.qcow2 | 14.671 | 9.193 | +---------------------------+---------+---------+ | /ssd/t-part-rand.qcow2 -w | 11.434 | 8.621 | +---------------------------+---------+---------+ | /ssd/t-rand.qcow2 | 20.421 | 10.05 | +---------------------------+---------+---------+ | /ssd/t-rand.qcow2 -w | 11.097 | 8.915 | +---------------------------+---------+---------+ | /ssd/t-reverse.qcow2 | 17.515 | 9.407 | +---------------------------+---------+---------+ | /ssd/t-reverse.qcow2 -w | 11.255 | 8.649 | +---------------------------+---------+---------+ | /ssd/t-seq.qcow2 | 9.081 | 9.072 | +---------------------------+---------+---------+ | /ssd/t-seq.qcow2 -w | 8.761 | 8.747 | +---------------------------+---------+---------+ | /tmp/t-part-rand.qcow2 | 41.179 | 41.37 | +---------------------------+---------+---------+ | /tmp/t-part-rand.qcow2 -w | 54.097 | 55.323 | +---------------------------+---------+---------+ | /tmp/t-rand.qcow2 | 711.899 | 514.339 | +---------------------------+---------+---------+ | /tmp/t-rand.qcow2 -w | 546.259 | 642.114 | +---------------------------+---------+---------+ | /tmp/t-reverse.qcow2 | 86.065 | 96.522 | +---------------------------+---------+---------+ | /tmp/t-reverse.qcow2 -w | 46.557 | 48.499 | +---------------------------+---------+---------+ | /tmp/t-seq.qcow2 | 33.804 | 33.862 | +---------------------------+---------+---------+ | /tmp/t-seq.qcow2 -w | 34.299 | 34.233 | +---------------------------+---------+---------+ Performance gain is obvious, especially for read and especially for ssd. For hdd there is a degradation for reverse case, but this is the most impossible case and seems not critical. How images are generated: ==== gen-writes ====== #!/usr/bin/env python import random import sys size = 4 * 1024 * 1024 * 1024 block = 64 * 1024 block2 = 1024 * 1024 arg = sys.argv[1] if arg in ('rand', 'reverse', 'seq'): writes = list(range(0, size, block)) if arg == 'rand': random.shuffle(writes) elif arg == 'reverse': writes.reverse() elif arg == 'part-rand': writes = [] for off in range(0, size, block2): wr = list(range(off, off + block2, block)) random.shuffle(wr) writes.extend(wr) elif arg != 'seq': sys.exit(1) for w in writes: print 'write -P 0xff {} {}'.format(w, block) print 'q' ========================== ===== gen-test-images.sh ===== #!/bin/bash IMG_PATH=/ssd for name in seq reverse rand part-rand; do IMG=$IMG_PATH/t-$name.qcow2 echo createing $IMG ... rm -f $IMG qemu-img create -f qcow2 $IMG 4G gen-writes $name | qemu-io $IMG done ============================== Vladimir Sementsov-Ogievskiy (4): block: introduce aio task pool block/qcow2: refactor qcow2_co_preadv_part block/qcow2: refactor qcow2_co_pwritev_part block/qcow2: introduce parallel subrequest handling in read and write qapi/block-core.json | 2 +- block/aio_task.h | 52 +++++ block/aio_task.c | 119 +++++++++++ block/qcow2.c | 459 ++++++++++++++++++++++++++++--------------- block/Makefile.objs | 2 + block/trace-events | 1 + 6 files changed, 477 insertions(+), 158 deletions(-) create mode 100644 block/aio_task.h create mode 100644 block/aio_task.c -- 2.18.0