From patchwork Tue Oct 26 16:23:44 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefano Garzarella X-Patchwork-Id: 12585171 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8D02CC433EF for ; Tue, 26 Oct 2021 16:26:48 +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 3763C60200 for ; Tue, 26 Oct 2021 16:26:48 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 3763C60200 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:40536 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mfPHj-00020Z-BD for qemu-devel@archiver.kernel.org; Tue, 26 Oct 2021 12:26:47 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:33312) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mfPF7-0007Tb-Jx for qemu-devel@nongnu.org; Tue, 26 Oct 2021 12:24:05 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:27531) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mfPF4-00039h-TG for qemu-devel@nongnu.org; Tue, 26 Oct 2021 12:24:05 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1635265442; 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: in-reply-to:in-reply-to:references:references; bh=vXCh4qUe77x9hH4BHdVWEe5c7Jef17EKcK+o72UZjhQ=; b=BBtUini+Z5znpeYmgvTQcNNSPgVxJZTOXd2xu4QMozP7jM4ozXNf3iIPmmpheLKEgnBzC8 28BofqpK4e00N0pBaaFPfCguZcSSdhiyjHP10TAR8MxJzqw72BPDVeX3vqB3wUrdbls/WO dKbunS3V/PMzhWlhr5dPDlByvxA+Ty4= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-595-BS1BcF0iP7CP_1FmYgEzwg-1; Tue, 26 Oct 2021 12:23:59 -0400 X-MC-Unique: BS1BcF0iP7CP_1FmYgEzwg-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 22C1D1006AA4; Tue, 26 Oct 2021 16:23:58 +0000 (UTC) Received: from steredhat.redhat.com (unknown [10.39.194.96]) by smtp.corp.redhat.com (Postfix) with ESMTP id 9827757CAA; Tue, 26 Oct 2021 16:23:56 +0000 (UTC) From: Stefano Garzarella To: qemu-devel@nongnu.org Subject: [PATCH v2 1/3] file-posix: add `aio-max-batch` option Date: Tue, 26 Oct 2021 18:23:44 +0200 Message-Id: <20211026162346.253081-2-sgarzare@redhat.com> In-Reply-To: <20211026162346.253081-1-sgarzare@redhat.com> References: <20211026162346.253081-1-sgarzare@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=sgarzare@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=216.205.24.124; envelope-from=sgarzare@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 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_LOW=-0.7, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action 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: Kevin Wolf , qemu-block@nongnu.org, Markus Armbruster , Hanna Reitz , Stefan Hajnoczi , Eric Blake Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Commit d7ddd0a161 ("linux-aio: limit the batch size using `aio-max-batch` parameter") added a way to limit the batch size of Linux AIO backend for the entire AIO context. The same AIO context can be shared by multiple devices, so latency-sensitive devices may want to limit the batch size even more to avoid increasing latency. For this reason we add the `aio-max-batch` option to the file backend, which will be used by the next commits to limit the size of batches including requests generated by this device. Suggested-by: Kevin Wolf Reviewed-by: Kevin Wolf Signed-off-by: Stefano Garzarella Reviewed-by: Stefan Hajnoczi --- Notes: v2: - @aio-max-batch documentation rewrite [Stefan, Kevin] qapi/block-core.json | 7 +++++++ block/file-posix.c | 9 +++++++++ 2 files changed, 16 insertions(+) diff --git a/qapi/block-core.json b/qapi/block-core.json index 6d3217abb6..fef76b0ea2 100644 --- a/qapi/block-core.json +++ b/qapi/block-core.json @@ -2896,6 +2896,12 @@ # for this device (default: none, forward the commands via SG_IO; # since 2.11) # @aio: AIO backend (default: threads) (since: 2.8) +# @aio-max-batch: maximum number of requests to batch together into a single +# submission in the AIO backend. The smallest value between +# this and the aio-max-batch value of the IOThread object is +# chosen. +# 0 means that the AIO backend will handle it automatically. +# (default: 0, since 6.2) # @locking: whether to enable file locking. If set to 'auto', only enable # when Open File Descriptor (OFD) locking API is available # (default: auto, since 2.10) @@ -2924,6 +2930,7 @@ '*pr-manager': 'str', '*locking': 'OnOffAuto', '*aio': 'BlockdevAioOptions', + '*aio-max-batch': 'int', '*drop-cache': {'type': 'bool', 'if': 'CONFIG_LINUX'}, '*x-check-cache-dropped': 'bool' }, diff --git a/block/file-posix.c b/block/file-posix.c index 53be0bdc1b..d655fd0c45 100644 --- a/block/file-posix.c +++ b/block/file-posix.c @@ -150,6 +150,8 @@ typedef struct BDRVRawState { uint64_t locked_perm; uint64_t locked_shared_perm; + uint64_t aio_max_batch; + int perm_change_fd; int perm_change_flags; BDRVReopenState *reopen_state; @@ -530,6 +532,11 @@ static QemuOptsList raw_runtime_opts = { .type = QEMU_OPT_STRING, .help = "host AIO implementation (threads, native, io_uring)", }, + { + .name = "aio-max-batch", + .type = QEMU_OPT_NUMBER, + .help = "AIO max batch size (0 = auto handled by AIO backend, default: 0)", + }, { .name = "locking", .type = QEMU_OPT_STRING, @@ -609,6 +616,8 @@ static int raw_open_common(BlockDriverState *bs, QDict *options, s->use_linux_io_uring = (aio == BLOCKDEV_AIO_OPTIONS_IO_URING); #endif + s->aio_max_batch = qemu_opt_get_number(opts, "aio-max-batch", 0); + locking = qapi_enum_parse(&OnOffAuto_lookup, qemu_opt_get(opts, "locking"), ON_OFF_AUTO_AUTO, &local_err);