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 E3450C77B73 for ; Tue, 2 May 2023 20:11:10 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ptwKg-0007QU-UU; Tue, 02 May 2023 16:10:42 -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 1ptwKe-0007Ps-OE for qemu-devel@nongnu.org; Tue, 02 May 2023 16:10:41 -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 1ptwKc-0001nj-9b for qemu-devel@nongnu.org; Tue, 02 May 2023 16:10:40 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1683058237; 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=G3M6X6Cb/uW8g9mA7FuVSmxMkf0IsGJPoGtjU0Aq7ck=; b=RZxDJe5lu4RnGcmN+KYDTrqtX7hrzuZzbT2Beipg3nNRdhCAPthdixq8qoRBt3l59wscW8 qcsgj0Zt4h1IxBUffsPO2o3AT1V9brxXxYH/02H2VCMtD8+VoZMDrUTwarfpMVchnSUVAo 6U8cRZm+2CHan+r0/c7LeYkJciKsnZA= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [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-215-bZJNyyK4N4GaEmywDujudQ-1; Tue, 02 May 2023 16:10:34 -0400 X-MC-Unique: bZJNyyK4N4GaEmywDujudQ-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 04349381D4CF; Tue, 2 May 2023 20:10:33 +0000 (UTC) Received: from localhost (unknown [10.39.192.230]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4A3BA2026D16; Tue, 2 May 2023 20:10:32 +0000 (UTC) Date: Tue, 2 May 2023 16:10:29 -0400 From: Stefan Hajnoczi To: Kevin Wolf Cc: qemu-devel@nongnu.org, Daniel =?iso-8859-1?Q?P=2E_Berrang=E9?= , Juan Quintela , Julia Suvorova , xen-devel@lists.xenproject.org, eesposit@redhat.com, Richard Henderson , Fam Zheng , "Michael S. Tsirkin" , Coiby Xu , David Woodhouse , Marcel Apfelbaum , Peter Lieven , Paul Durrant , "Richard W.M. Jones" , qemu-block@nongnu.org, Stefano Garzarella , Anthony Perard , Stefan Weil , Xie Yongji , Paolo Bonzini , Aarushi Mehta , Philippe =?iso-8859-1?Q?Mathieu-Daud=E9?= , Eduardo Habkost , Stefano Stabellini , Hanna Reitz , Ronnie Sahlberg Subject: Re: [PATCH v4 10/20] block: drain from main loop thread in bdrv_co_yield_to_drain() Message-ID: <20230502201029.GF535070@fedora> References: <20230425172716.1033562-1-stefanha@redhat.com> <20230425172716.1033562-11-stefanha@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="brpBxr+X1vKHT7XM" Content-Disposition: inline In-Reply-To: X-Scanned-By: MIMEDefang 3.1 on 10.11.54.4 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: -22 X-Spam_score: -2.3 X-Spam_bar: -- X-Spam_report: (-2.3 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.171, 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_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 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 --brpBxr+X1vKHT7XM Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, May 02, 2023 at 06:21:20PM +0200, Kevin Wolf wrote: > Am 25.04.2023 um 19:27 hat Stefan Hajnoczi geschrieben: > > For simplicity, always run BlockDevOps .drained_begin/end/poll() > > callbacks in the main loop thread. This makes it easier to implement the > > callbacks and avoids extra locks. > >=20 > > Move the function pointer declarations from the I/O Code section to the > > Global State section in block-backend-common.h. > >=20 > > Signed-off-by: Stefan Hajnoczi >=20 > If we're updating function pointers, we should probably update them in > BdrvChildClass and BlockDriver, too. I'll do that in the next revision. > This means that a non-coroutine caller can't run in an iothread, not > even the home iothread of the BlockDriverState. (I'm not sure if it was > allowed previously. I don't think we're actually doing this, but in > theory it could have worked.) Maybe put a GLOBAL_STATE_CODE() after > handling the bdrv_co_yield_to_drain() case? Or would that look too odd? >=20 > IO_OR_GS_CODE(); >=20 > if (qemu_in_coroutine()) { > bdrv_co_yield_to_drain(bs, true, parent, poll); > return; > } >=20 > GLOBAL_STATE_CODE(); That looks good to me, it makes explicit that IO_OR_GS_CODE() only applies until the end of the if statement. Stefan --brpBxr+X1vKHT7XM Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEhpWov9P5fNqsNXdanKSrs4Grc8gFAmRRbjUACgkQnKSrs4Gr c8gcCwf/T65LBfJJcwJAyvlXRfg2oJ/yZvsfJ3BZCAaupLZjx+EeDLlXwOdhSb2S GKjZnCRY+804xb2asfcWI/aD6+FfB/OtlSQmoNpLQ0rRSl0ySEwoAolto1Z9ekGZ L+Jfc76d+YxOe+NNrrZ9OzISmnofdrQVvqoJotHO/4bB0pUPvWzJG4f+ji/jy3u/ A+7u0pbN8C5zVOa6Cd3OXliYePtIv3nGH9xL8HmL/6YQD5rcPgFj2HlylhSMjRqy dY54mvDssnwZL5sI2RfogH00TesZlaXrVwMD5Mr+HJ/T5H3myPLw1Y3RCgiPVLCM WUaRx6PORhkBp198DzErfTVGl1grqQ== =G1hQ -----END PGP SIGNATURE----- --brpBxr+X1vKHT7XM--