Message ID | 20200610190058.10781-1-den@openvz.org (mailing list archive) |
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Headers | show
Return-Path: <SRS0=8n1M=7X=nongnu.org=qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@kernel.org> 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 BC49414E3 for <patchwork-qemu-devel@patchwork.kernel.org>; Wed, 10 Jun 2020 19:06:39 +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 9CAB7206F7 for <patchwork-qemu-devel@patchwork.kernel.org>; Wed, 10 Jun 2020 19:06:39 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9CAB7206F7 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=openvz.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Received: from localhost ([::1]:36078 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from <qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org>) id 1jj63a-0003gS-Tm for patchwork-qemu-devel@patchwork.kernel.org; Wed, 10 Jun 2020 15:06:38 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:56178) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from <den@openvz.org>) id 1jj5yP-00064k-Ls; Wed, 10 Jun 2020 15:01:17 -0400 Received: from relay.sw.ru ([185.231.240.75]:42682 helo=relay3.sw.ru) by eggs.gnu.org with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from <den@openvz.org>) id 1jj5yA-0005PW-8k; Wed, 10 Jun 2020 15:01:17 -0400 Received: from [192.168.15.9] (helo=iris.lishka.ru) by relay3.sw.ru with esmtp (Exim 4.93) (envelope-from <den@openvz.org>) id 1jj5y6-0007vZ-7m; Wed, 10 Jun 2020 22:00:58 +0300 From: "Denis V. Lunev" <den@openvz.org> To: qemu-block@nongnu.org, qemu-devel@nongnu.org Subject: [PATCH v2 0/2] qcow2: seriously improve savevm performance Date: Wed, 10 Jun 2020 22:00:56 +0300 Message-Id: <20200610190058.10781-1-den@openvz.org> X-Mailer: git-send-email 2.17.1 Received-SPF: pass client-ip=185.231.240.75; envelope-from=den@openvz.org; helo=relay3.sw.ru X-detected-operating-system: by eggs.gnu.org: First seen = 2020/06/10 14:58:35 X-ACL-Warn: Detected OS = Linux 3.11 and newer X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=_AUTOLEARN X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: <qemu-devel.nongnu.org> List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>, <mailto:qemu-devel-request@nongnu.org?subject=unsubscribe> List-Archive: <https://lists.nongnu.org/archive/html/qemu-devel> List-Post: <mailto:qemu-devel@nongnu.org> List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help> List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>, <mailto:qemu-devel-request@nongnu.org?subject=subscribe> Cc: Kevin Wolf <kwolf@redhat.com>, "Denis V . Lunev" <den@openvz.org>, Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>, Denis Plotnikov <dplotnikov@virtuozzo.com>, Max Reitz <mreitz@redhat.com> Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" <qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org> |
Series |
qcow2: seriously improve savevm performance
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expand
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This series do standard basic things: - it creates intermediate buffer for all writes from QEMU migration code to QCOW2 image, - this buffer is sent to disk asynchronously, allowing several writes to run in parallel. In general, migration code is fantastically inefficent (by observation), buffers are not aligned and sent with arbitrary pieces, a lot of time less than 100 bytes at a chunk, which results in read-modify-write operations with non-cached operations. It should also be noted that all operations are performed into unallocated image blocks, which also suffer due to partial writes to such new clusters. This patch series is an implementation of idea discussed in the RFC posted by Denis https://lists.gnu.org/archive/html/qemu-devel/2020-04/msg01925.html Results with this series over NVME are better than original code original rfc this cached: 1.79s 2.38s 1.27s non-cached: 3.29s 1.31s 0.81s Changes from v1: - patchew warning fixed - fixed validation that only 1 waiter is allowed in patch 1 Signed-off-by: Denis V. Lunev <den@openvz.org> CC: Kevin Wolf <kwolf@redhat.com> CC: Max Reitz <mreitz@redhat.com> CC: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> CC: Denis Plotnikov <dplotnikov@virtuozzo.com>