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 X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E1DB7C31E46 for ; Wed, 12 Jun 2019 14:48:01 +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 BA9A5208CA for ; Wed, 12 Jun 2019 14:48:01 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BA9A5208CA Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:32894 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hb4Xg-0007hU-Qq for qemu-devel@archiver.kernel.org; Wed, 12 Jun 2019 10:48:00 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:53660) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hb4Tu-0006e2-Vz for qemu-devel@nongnu.org; Wed, 12 Jun 2019 10:44:08 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hb4Tt-0004JB-F3 for qemu-devel@nongnu.org; Wed, 12 Jun 2019 10:44:06 -0400 Received: from mx1.redhat.com ([209.132.183.28]:49286) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hb4Tn-00046d-Ap; Wed, 12 Jun 2019 10:43:59 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 5EAAB30860A6; Wed, 12 Jun 2019 14:43:51 +0000 (UTC) Received: from localhost (unknown [10.36.118.30]) by smtp.corp.redhat.com (Postfix) with ESMTP id 8E2DA60BF1; Wed, 12 Jun 2019 14:43:46 +0000 (UTC) Date: Wed, 12 Jun 2019 15:43:40 +0100 From: Stefan Hajnoczi To: Fam Zheng Message-ID: <20190612144340.GF19156@stefanha-x1.localdomain> References: <20190610134905.22294-1-mehta.aaru20@gmail.com> <20190610134905.22294-5-mehta.aaru20@gmail.com> <20190611111714.wshlk6fddh34atfp@debian> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="9ADF8FXzFeE7X4jE" Content-Disposition: inline In-Reply-To: <20190611111714.wshlk6fddh34atfp@debian> User-Agent: Mutt/1.11.4 (2019-03-13) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.44]); Wed, 12 Jun 2019 14:43:51 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: Re: [Qemu-devel] [PATCH v5 04/12] block/io_uring: implements interfaces for io_uring 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 , Sergio Lopez , qemu-block@nongnu.org, qemu-devel@nongnu.org, Max Reitz , saket.sinha89@gmail.com, Paolo Bonzini , Maxim Levitsky , Julia Suvorova , Aarushi Mehta , Markus Armbruster Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" --9ADF8FXzFeE7X4jE Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Jun 11, 2019 at 07:17:14PM +0800, Fam Zheng wrote: > On Mon, 06/10 19:18, Aarushi Mehta wrote: > > + /* Prevent infinite loop if submission is refused */ > > + if (ret <=3D 0) { > > + if (ret =3D=3D -EAGAIN) { > > + continue; > > + } > > + break; > > + } > > + s->io_q.in_flight +=3D ret; > > + s->io_q.in_queue -=3D ret; > > + } > > + s->io_q.blocked =3D (s->io_q.in_queue > 0); >=20 > I'm confused about s->io_q.blocked. ioq_submit is where it gets updated, = but > if it becomes true, calling ioq_submit will be fenced. So how does it get > cleared? When blocked, additional I/O requests are not submitted until the next completion. See qemu_luring_process_completions_and_submit() for the code path where ioq_submit() gets called again. Stefan --9ADF8FXzFeE7X4jE Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEhpWov9P5fNqsNXdanKSrs4Grc8gFAl0BD5wACgkQnKSrs4Gr c8gGfgf/buzOhb/HLEA21dK4NmmRkG7Zg6MZpCQ0AbzBfSnJNJdjo+it/mdr/1zK soJcpua7YweXG2/Fzm0WLj0cTfX8GmTeVg7a0MR2TmtE5fm8g+2DyD0yrqfvbj6v YPxtO3K1NCzEeujMbx6H3slqamCnSo1z2pztvaI+/TU5mkp1VSL9rsnlvsX6Q+lP w314fTD78sEDrxurKqhWJ/5esFs+5AyP0qVUK8CThxNrsIaKnnZSzcX1xYbia3LS LmvOnOOIktJ2SQvjjfzE0z5w8TdXPETqJeICmqJcpJa1u3FuYYbXbY8/Gw23HWm/ 5Vj9eqaQYbjA6tqiJ3vh57f+eZJ57w== =lXPW -----END PGP SIGNATURE----- --9ADF8FXzFeE7X4jE--