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 A304EC61DA4 for ; Mon, 6 Mar 2023 14:39:15 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pZBzY-0005hv-UV; Mon, 06 Mar 2023 09:39:08 -0500 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 1pZBzW-0005hm-Gg for qemu-devel@nongnu.org; Mon, 06 Mar 2023 09:39:06 -0500 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 1pZBzU-0006a9-VW for qemu-devel@nongnu.org; Mon, 06 Mar 2023 09:39:06 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1678113543; 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=KvwBrqlYLSgRYlLD9r1fbJPuh1IYkfg+rVXkMnOvXIM=; b=bKYG4dsjuPcatL+v+mj+7HsWjkBaOoWFxqGKb8BaroC01ymEs/Co2+IID01ZUECUsG4lmB HR4JeCfCEQmKqFSQnlY4BkTPJNOYDCGD6++b6iCPcVdKdNb1YqFGhNehA/zP7HQZaHYN0j lHeOI5f4+o7dB1mFiHq70vu3JzwA4GM= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-631-msyQ8z72NMSy_1rJLYKqdg-1; Mon, 06 Mar 2023 09:38:59 -0500 X-MC-Unique: msyQ8z72NMSy_1rJLYKqdg-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 05854858F09 for ; Mon, 6 Mar 2023 14:38:59 +0000 (UTC) Received: from localhost (unknown [10.39.195.176]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5DA7D2026D4B; Mon, 6 Mar 2023 14:38:58 +0000 (UTC) Date: Mon, 6 Mar 2023 09:38:56 -0500 From: Stefan Hajnoczi To: Paolo Bonzini Cc: qemu-devel@nongnu.org, gshan@redhat.com, eesposit@redhat.com, david@redhat.com, cohuck@redhat.com, eauger@redhat.com Subject: Re: [PATCH 6/8] aio-wait: switch to smp_mb__after_rmw() Message-ID: <20230306143856.GA51288@fedora> References: <20230303171939.237819-1-pbonzini@redhat.com> <20230303171939.237819-7-pbonzini@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="+P2yTTlLIhP94FEM" Content-Disposition: inline In-Reply-To: <20230303171939.237819-7-pbonzini@redhat.com> 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: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, 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 autolearn=ham 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 --+P2yTTlLIhP94FEM Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Mar 03, 2023 at 06:19:37PM +0100, Paolo Bonzini wrote: > The barrier comes after an atomic increment, so it is enough to use > smp_mb__after_rmw(); this avoids a double barrier on x86 systems. >=20 > Signed-off-by: Paolo Bonzini > --- > include/block/aio-wait.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) Reviewed-by: Stefan Hajnoczi --+P2yTTlLIhP94FEM Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEhpWov9P5fNqsNXdanKSrs4Grc8gFAmQF+wAACgkQnKSrs4Gr c8iJywf/dNocRuREiR1kReaxntPhqXfwH2jXfXNX8gq/Mq9CcBTF5VoU/pbcCt+5 +sdXQtyBjPJqlBrHTWdfOCPKE2NmR1ZKSKf0VrfQIFWhGmpIthsvLd4h31b7pY22 EEbtvw1peKF3k7r3X4CqHE3HphwlZnQWQepbnLDo51GrarIJxqVKr1OrAqpFE8wE me5gdEEhYoaB8wNe8aPCp8HmY9O9GcHfYzD5W4HZbbVcF+CBFrYfDCQvlxPjKHrz sAZgZJt8nkjZdPBKSb3un6XsIp7FluStguMDG4uCn0PHO9ipOh+1vODMalcgTeCJ YlzKQyN0fzFurQXVXAkXlCiimtlH0g== =FDHq -----END PGP SIGNATURE----- --+P2yTTlLIhP94FEM--