From patchwork Tue Aug 8 15:58:50 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Hajnoczi X-Patchwork-Id: 13346269 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org 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 smtp.lore.kernel.org (Postfix) with ESMTPS id D148FC001B0 for ; Tue, 8 Aug 2023 16:15:15 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qTPLw-0007Ee-8i; Tue, 08 Aug 2023 12:14:36 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qTPLu-0007EF-BR for qemu-devel@nongnu.org; Tue, 08 Aug 2023 12:14:34 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qTPLs-0007kx-7F for qemu-devel@nongnu.org; Tue, 08 Aug 2023 12:14:34 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1691511271; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=0fqPcZ7mlhuMJS4OQ3aifegGA0OtFOF7lVQ80jV5ak8=; b=OTr5i9crZiaf+BlmvI36L9F0r4mVQBG2gzO7bSQWaDzZw3vIWGeVkg1P/LSKcv/X0TlfMk eIiKK5d+RLcR2Tplm3eScVCCxpgRM8w9L+udjqW4DlqDbPeykLZRaQuRWoyBTLlh/aIinP PQzPs0fkGyITz0Hcqw+RqlBWj5xlZ5U= Received: from mimecast-mx02.redhat.com (66.187.233.73 [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-551-CeKQVaHhMVSRV9OZMzBH8w-1; Tue, 08 Aug 2023 12:14:28 -0400 X-MC-Unique: CeKQVaHhMVSRV9OZMzBH8w-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id A1A96280FECB; Tue, 8 Aug 2023 16:14:27 +0000 (UTC) Received: from localhost (unknown [10.39.193.72]) by smtp.corp.redhat.com (Postfix) with ESMTP id 038682166B25; Tue, 8 Aug 2023 16:14:26 +0000 (UTC) From: Stefan Hajnoczi To: qemu-devel@nongnu.org Cc: Kevin Wolf , Fam Zheng , qemu-block@nongnu.org, Hanna Reitz , Stefan Hajnoczi Subject: [PATCH 0/2] block: change reqs_lock to QemuMutex Date: Tue, 8 Aug 2023 11:58:50 -0400 Message-ID: <20230808155852.2745350-1-stefanha@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.6 Received-SPF: pass client-ip=170.10.129.124; envelope-from=stefanha@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org As part of the ongoing multi-queue QEMU block layer work, I found that CoMutex reqs_lock scales poorly when more IOThreads are added. These patches double IOPS in the 4 IOThreads randread benchmark that I have been running with my out-of-tree virtio-blk-iothread-vq-mapping branch (https://gitlab.com/stefanha/qemu/-/commits/virtio-blk-iothread-vq-mapping). These patches can be merged in preparation for virtio-blk multi-queue block layer support. Stefan Hajnoczi (2): block: minimize bs->reqs_lock section in tracked_request_end() block: change reqs_lock to QemuMutex include/block/block_int-common.h | 2 +- block.c | 4 +++- block/io.c | 30 ++++++++++++++++++------------ 3 files changed, 22 insertions(+), 14 deletions(-)