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=-6.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS 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 DD6B9C433DF for ; Thu, 9 Jul 2020 11:43:15 +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 A7A9F206DF for ; Thu, 9 Jul 2020 11:43:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Nhn0KDMD" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A7A9F206DF 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]:42532 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jtUxO-0006EM-OG for qemu-devel@archiver.kernel.org; Thu, 09 Jul 2020 07:43:14 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:56484) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jtUwj-0005nB-Ac for qemu-devel@nongnu.org; Thu, 09 Jul 2020 07:42:33 -0400 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:26141 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1jtUwh-0003r2-RJ for qemu-devel@nongnu.org; Thu, 09 Jul 2020 07:42:33 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1594294950; 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=O3AcFV4MrSzWzboIWpst2gjfaCJaL1e3u9J77xugnxY=; b=Nhn0KDMDjLpdGPQzSpOZ4L9jopjm0rCjv2YvTQsS4wA+tyuwsToGjH8Ho1Wh07PDG8eHMd 2TX9gU+09J+XpR7rCi9Uv9LHwa5lJDUoCtT9+WayQoGnFuDIJysawdUCkBe9w+jvhK/tvA GdkPpWK/a0lBrrhAQ3Uehn1kQA3DJ3E= 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-195-f9hv5HCrMtCpx7i_sNT6iw-1; Thu, 09 Jul 2020 07:42:28 -0400 X-MC-Unique: f9hv5HCrMtCpx7i_sNT6iw-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id B88E310059A2; Thu, 9 Jul 2020 11:42:27 +0000 (UTC) Received: from blackfin.pond.sub.org (ovpn-112-143.ams2.redhat.com [10.36.112.143]) by smtp.corp.redhat.com (Postfix) with ESMTPS id B9CD419D7B; Thu, 9 Jul 2020 11:42:24 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 4674A1132FD2; Thu, 9 Jul 2020 13:42:23 +0200 (CEST) From: Markus Armbruster To: Maxim Levitsky Subject: Re: [PATCH v2 2/7] Implement drain_call_rcu and use it in hmp_device_del References: <20200511160951.8733-1-mlevitsk@redhat.com> <20200511160951.8733-3-mlevitsk@redhat.com> Date: Thu, 09 Jul 2020 13:42:23 +0200 In-Reply-To: <20200511160951.8733-3-mlevitsk@redhat.com> (Maxim Levitsky's message of "Mon, 11 May 2020 19:09:46 +0300") Message-ID: <87wo3csyn4.fsf@dusky.pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.3 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=armbru@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain Received-SPF: pass client-ip=207.211.31.81; envelope-from=armbru@redhat.com; helo=us-smtp-delivery-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/07/09 04:33:23 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -30 X-Spam_score: -3.1 X-Spam_bar: --- X-Spam_report: (-3.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1, 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_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, 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: Fam Zheng , "Daniel P. =?utf-8?Q?Berrang=C3=A9?=" , Eduardo Habkost , "Michael S. Tsirkin" , qemu-devel@nongnu.org, Paolo Bonzini Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Maxim Levitsky writes: > This allows to preserve the semantics of hmp_device_del, > that the device is deleted immediatly which was changed by previos > patch that delayed this to RCU callback > > Suggested-by: Stefan Hajnoczi > Signed-off-by: Maxim Levitsky > --- > include/qemu/rcu.h | 1 + > qdev-monitor.c | 3 +++ > util/rcu.c | 33 +++++++++++++++++++++++++++++++++ > 3 files changed, 37 insertions(+) > > diff --git a/include/qemu/rcu.h b/include/qemu/rcu.h > index 570aa603eb..0e375ebe13 100644 > --- a/include/qemu/rcu.h > +++ b/include/qemu/rcu.h > @@ -133,6 +133,7 @@ struct rcu_head { > }; > > extern void call_rcu1(struct rcu_head *head, RCUCBFunc *func); > +extern void drain_call_rcu(void); > > /* The operands of the minus operator must have the same type, > * which must be the one that we specify in the cast. > diff --git a/qdev-monitor.c b/qdev-monitor.c > index 56cee1483f..70877840a2 100644 > --- a/qdev-monitor.c > +++ b/qdev-monitor.c > @@ -812,6 +812,8 @@ void qmp_device_add(QDict *qdict, QObject **ret_data, Error **errp) > return; > } > dev = qdev_device_add(opts, &local_err); > + drain_call_rcu(); > + > if (!dev) { > error_propagate(errp, local_err); > qemu_opts_del(opts); > @@ -904,6 +906,7 @@ void qmp_device_del(const char *id, Error **errp) > } > > qdev_unplug(dev, errp); > + drain_call_rcu(); > } > } > Subject claims "in hmp_device_del", code has it in qmp_device_add() and qmp_device_del(). Please advise. [...]