From patchwork Mon May 28 07:19:56 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Xu X-Patchwork-Id: 921345 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=2001:4830:134:3::11; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=redhat.com Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 40vT270Y07z9s08 for ; Mon, 28 May 2018 17:26:54 +1000 (AEST) Received: from localhost ([::1]:54595 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fNCYO-0005xQ-JN for incoming@patchwork.ozlabs.org; Mon, 28 May 2018 03:26:52 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35544) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fNCS3-0001H4-B9 for qemu-devel@nongnu.org; Mon, 28 May 2018 03:20:20 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fNCRy-0003d1-Qq for qemu-devel@nongnu.org; Mon, 28 May 2018 03:20:19 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:46244 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fNCRy-0003cf-MB for qemu-devel@nongnu.org; Mon, 28 May 2018 03:20:14 -0400 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 mx1.redhat.com (Postfix) with ESMTPS id 54A59818BAF3 for ; Mon, 28 May 2018 07:20:14 +0000 (UTC) Received: from xz-mi.redhat.com (ovpn-12-93.pek2.redhat.com [10.72.12.93]) by smtp.corp.redhat.com (Postfix) with ESMTP id 651912026DEF; Mon, 28 May 2018 07:20:11 +0000 (UTC) From: Peter Xu To: qemu-devel@nongnu.org Date: Mon, 28 May 2018 15:19:56 +0800 Message-Id: <20180528071958.17053-4-peterx@redhat.com> In-Reply-To: <20180528071958.17053-1-peterx@redhat.com> References: <20180528071958.17053-1-peterx@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.4 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Mon, 28 May 2018 07:20:14 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Mon, 28 May 2018 07:20:14 +0000 (UTC) for IP:'10.11.54.4' DOMAIN:'int-mx04.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'peterx@redhat.com' RCPT:'' X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 66.187.233.73 Subject: [Qemu-devel] [PATCH v8 3/5] monitor: more comments on lock-free elements X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Markus Armbruster , peterx@redhat.com, "Dr . David Alan Gilbert" , Stefan Hajnoczi , =?utf-8?q?Marc-Andr=C3=A9_Lureau?= Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" Add some explicit comments for both Readline and cpu_set/cpu_get helpers that they do not need the mon_lock protection. Signed-off-by: Peter Xu --- monitor.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/monitor.c b/monitor.c index d6c3c08932..f23178951e 100644 --- a/monitor.c +++ b/monitor.c @@ -207,7 +207,15 @@ struct Monitor { int suspend_cnt; /* Needs to be accessed atomically */ bool skip_flush; bool use_io_thr; + + /* + * State used only in the thread "owning" the monitor. + * If @use_io_thr, this is mon_global.mon_iothread. + * Else, it's the main thread. + * These members can be safely accessed without locks. + */ ReadLineState *rs; + MonitorQMP qmp; gchar *mon_cpu_path; BlockCompletionFunc *password_completion_cb; @@ -1313,7 +1321,7 @@ void qmp_qmp_capabilities(bool has_enable, QMPCapabilityList *enable, cur_mon->qmp.commands = &qmp_commands; } -/* set the current CPU defined by the user */ +/* Set the current CPU defined by the user. Callers must hold BQL. */ int monitor_set_cpu(int cpu_index) { CPUState *cpu; @@ -1327,6 +1335,7 @@ int monitor_set_cpu(int cpu_index) return 0; } +/* Callers must hold BQL. */ static CPUState *mon_get_cpu_sync(bool synchronize) { CPUState *cpu;