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 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 96279C54E71 for ; Wed, 21 May 2025 15:24:36 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1uHlIH-0007xX-PV; Wed, 21 May 2025 11:23:45 -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 1uHlIF-0007xM-Ck for qemu-devel@nongnu.org; Wed, 21 May 2025 11:23:43 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1uHlI7-0003XN-D8 for qemu-devel@nongnu.org; Wed, 21 May 2025 11:23:43 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1747841012; 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: in-reply-to:in-reply-to:references:references; bh=ET53qD0Rw/eEsVRB03imsJfLnHW0LRdAFYHfhMYnBbE=; b=S3T1wkix34+WCFKzD7YkeZ04CrMxIdxcFnbp5+XC21wmWrtrT53O21O0MkIUH7UYFWyCrZ NqiTtWtolvMUW3pXsZHpbp4iSvSSPGNwtuKushRAFoilTsfGVwy0hO+5COxGwnjx12ILFn t7W2Kluy3+zGI4YvNllQyjRzalMJtZ4= Received: from mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-550-5wT6UWieMsysYV_tdb2VDg-1; Wed, 21 May 2025 11:23:31 -0400 X-MC-Unique: 5wT6UWieMsysYV_tdb2VDg-1 X-Mimecast-MFC-AGG-ID: 5wT6UWieMsysYV_tdb2VDg_1747841009 Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 25648180087E; Wed, 21 May 2025 15:23:28 +0000 (UTC) Received: from redhat.com (unknown [10.45.226.112]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 1261F30001AA; Wed, 21 May 2025 15:23:20 +0000 (UTC) Date: Wed, 21 May 2025 17:23:18 +0200 From: Kevin Wolf To: Fiona Ebner Cc: qemu-block@nongnu.org, qemu-devel@nongnu.org, den@virtuozzo.com, andrey.drobyshev@virtuozzo.com, hreitz@redhat.com, stefanha@redhat.com, eblake@redhat.com, jsnow@redhat.com, vsementsov@yandex-team.ru, xiechanglong.d@gmail.com, wencongyang2@huawei.com, berto@igalia.com, fam@euphon.net, ari@tuxera.com Subject: Re: [PATCH v2 06/24] block: mark change_aio_ctx() callback and instances as GRAPH_RDLOCK(_PTR) Message-ID: References: <20250520103012.424311-1-f.ebner@proxmox.com> <20250520103012.424311-7-f.ebner@proxmox.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250520103012.424311-7-f.ebner@proxmox.com> X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 Received-SPF: pass client-ip=170.10.133.124; envelope-from=kwolf@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -22 X-Spam_score: -2.3 X-Spam_bar: -- X-Spam_report: (-2.3 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.184, 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_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=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 Am 20.05.2025 um 12:29 hat Fiona Ebner geschrieben: > This is a small step in preparation to mark bdrv_drained_begin() as > GRAPH_UNLOCKED. More concretely, it is in preparatoin to move the > drain out of bdrv_change_aio_context() and marking that function as > GRAPH_RDLOCK. > > Signed-off-by: Fiona Ebner I noticed that all existing callers of .change_aio_ctx() apart from the one annotated only in the previous patch are in fact even GRAPH_WRLOCK. Maybe it's not important any more nowadays given that the assigned AioContext of a block node is more of a default, but traditionally I think it would have made sense to treat changing the AioContext as changing the graph, i.e. bs->aio_context could have been GRAPH_WRLOCK. Just posting this in case someone has more thoughts on it. I don't necessarily disagree with using GRAPH_RDLOCK. Reviewed-by: Kevin Wolf