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=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 CB39FC04AAF for ; Tue, 21 May 2019 02:29:54 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id A38042171F for ; Tue, 21 May 2019 02:29:54 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A38042171F 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 ([127.0.0.1]:45233 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hSuXJ-0007Ka-KH for qemu-devel@archiver.kernel.org; Mon, 20 May 2019 22:29:53 -0400 Received: from eggs.gnu.org ([209.51.188.92]:46510) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hSuWU-00071h-NE for qemu-devel@nongnu.org; Mon, 20 May 2019 22:29:03 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hSuWT-0005HZ-Tr for qemu-devel@nongnu.org; Mon, 20 May 2019 22:29:02 -0400 Received: from mx1.redhat.com ([209.132.183.28]:60324) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hSuWT-0005H5-OG for qemu-devel@nongnu.org; Mon, 20 May 2019 22:29:01 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id B36DC37EE7 for ; Tue, 21 May 2019 02:29:00 +0000 (UTC) Received: from xz-x1 (dhcp-15-205.nay.redhat.com [10.66.15.205]) by smtp.corp.redhat.com (Postfix) with ESMTPS id BFA075D9C8; Tue, 21 May 2019 02:28:58 +0000 (UTC) Date: Tue, 21 May 2019 10:28:56 +0800 From: Peter Xu To: Paolo Bonzini Message-ID: <20190521022856.GQ16681@xz-x1> References: <20190520030839.6795-1-peterx@redhat.com> <20190520030839.6795-4-peterx@redhat.com> <30752917-8ec0-492c-bba2-e6a31a56e858@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <30752917-8ec0-492c-bba2-e6a31a56e858@redhat.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Tue, 21 May 2019 02:29:00 +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 v2 03/15] migration: No need to take rcu during sync_dirty_bitmap 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: Laurent Vivier , qemu-devel@nongnu.org, "Dr . David Alan Gilbert" , Juan Quintela Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Mon, May 20, 2019 at 12:48:01PM +0200, Paolo Bonzini wrote: > On 20/05/19 05:08, Peter Xu wrote: > > cpu_physical_memory_sync_dirty_bitmap() has one RAMBlock* as > > parameter, which means that it must be with RCU read lock held > > already. Taking it again inside seems redundant. Removing it. > > Instead comment on the functions about the RCU read lock. > > > > Reviewed-by: Paolo Bonzini > > Signed-off-by: Peter Xu > > --- > > include/exec/ram_addr.h | 5 +---- > > migration/ram.c | 1 + > > 2 files changed, 2 insertions(+), 4 deletions(-) > > > > diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h > > index 139ad79390..993fb760f3 100644 > > --- a/include/exec/ram_addr.h > > +++ b/include/exec/ram_addr.h > > @@ -408,6 +408,7 @@ static inline void cpu_physical_memory_clear_dirty_range(ram_addr_t start, > > } > > > > > > +/* Must be with rcu read lock held */ > > The usual way to spell this is "Called within RCU critical section.", > otherwise the patch looks good. Sure, I'm switching to this with the r-b kept. Thanks, -- Peter Xu