From patchwork Tue Aug 15 12:08:03 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Hajnoczi X-Patchwork-Id: 1821350 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: legolas.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=DGmxcwa3; dkim-atps=neutral Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4RQ96c4Sqfz1yfb for ; Tue, 15 Aug 2023 22:09:11 +1000 (AEST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qVsqP-0000KF-7E; Tue, 15 Aug 2023 08:08:17 -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 1qVsqN-0000HP-IB for qemu-devel@nongnu.org; Tue, 15 Aug 2023 08:08:15 -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 1qVsqL-00053f-9J for qemu-devel@nongnu.org; Tue, 15 Aug 2023 08:08:15 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1692101292; 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=vJ6oZfoGdjd/8MI8L03eqn4G39VqBn+QC+fNpvcZ1pI=; b=DGmxcwa3t45NzQwmmmGRYf+dgLAglpD9kJzXsXCRqACFpVYC8zTBLCNd2xQpfbIXl1nLYi g+rVxd1RGxrW+UOZwq+YrgIVy6+yJ8G6uVsCMVJaQEKf1TleU41vAdFXMMGYgh3K0XyTTB b54Z68knUDIoCkxMfHu9fqdKMcI3CX0= 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-435-o4fnwk_mMJ2TjZAJXgsVMg-1; Tue, 15 Aug 2023 08:08:08 -0400 X-MC-Unique: o4fnwk_mMJ2TjZAJXgsVMg-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 2373B3828891; Tue, 15 Aug 2023 12:08:08 +0000 (UTC) Received: from localhost (unknown [10.39.193.40]) by smtp.corp.redhat.com (Postfix) with ESMTP id 98C3B492C13; Tue, 15 Aug 2023 12:08:07 +0000 (UTC) From: Stefan Hajnoczi To: qemu-devel@nongnu.org Cc: Hanna Reitz , , Julia Suvorova , Aarushi Mehta , Stefano Garzarella , Kevin Wolf , "Michael S. Tsirkin" , Stefan Hajnoczi Subject: [PATCH 0/2] virtio-blk: use blk_io_plug_call() instead of notification BH Date: Tue, 15 Aug 2023 08:08:03 -0400 Message-ID: <20230815120805.3235166-1-stefanha@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.9 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=-0.04, 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+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Replace the seldom-used virtio-blk notification BH mechanism with blk_io_plug(). This is part of an effort to enable the multi-queue block layer in virtio-blk. The notification BH was not multi-queue friendly. The blk_io_plug() mechanism improves fio rw=randread bs=4k iodepth=64 numjobs=8 IOPS by ~9% with a single IOThread and 8 vCPUs (this is not even a multi-queue block layer configuration) compared to no completion batching. iodepth=1 decreases by ~1% but this could be noise. Benchmark details are available here: https://gitlab.com/stefanha/virt-playbooks/-/tree/blk_io_plug-irqfd Stefan Hajnoczi (2): virtio: use blk_io_plug_call() in virtio_irqfd_notify() virtio-blk: remove batch notification BH block/io_uring.c | 6 +++++ block/linux-aio.c | 4 +++ hw/block/dataplane/virtio-blk.c | 48 +-------------------------------- hw/virtio/virtio.c | 10 ++++++- 4 files changed, 20 insertions(+), 48 deletions(-)