From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:41761) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZZa22-0001wk-Rx for qemu-devel@nongnu.org; Wed, 09 Sep 2015 03:43:03 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZZa21-0006yD-QO for qemu-devel@nongnu.org; Wed, 09 Sep 2015 03:43:02 -0400 Message-ID: <55EFE2AA.7060500@cn.fujitsu.com> Date: Wed, 9 Sep 2015 15:41:30 +0800 From: Zhu Guihua MIME-Version: 1.0 References: <1438838837-28504-1-git-send-email-bharata@linux.vnet.ibm.com> <1438838837-28504-2-git-send-email-bharata@linux.vnet.ibm.com> <20150904053124.GV6537@voom.redhat.com> <20150909055246.GD17433@in.ibm.com> In-Reply-To: <20150909055246.GD17433@in.ibm.com> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [RFC PATCH v4 01/11] exec: Remove cpu from cpus list during cpu_exec_exit() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: bharata@linux.vnet.ibm.com, David Gibson Cc: agraf@suse.de, aik@ozlabs.ru, qemu-devel@nongnu.org, mdroth@linux.vnet.ibm.com, qemu-ppc@nongnu.org, tyreld@linux.vnet.ibm.com, imammedo@redhat.com, nfont@linux.vnet.ibm.com, afaerber@suse.de On 09/09/2015 01:52 PM, Bharata B Rao wrote: > On Fri, Sep 04, 2015 at 03:31:24PM +1000, David Gibson wrote: >> On Thu, Aug 06, 2015 at 10:57:07AM +0530, Bharata B Rao wrote: >>> CPUState *cpu gets added to the cpus list during cpu_exec_init(). It >>> should be removed from cpu_exec_exit(). >>> >>> cpu_exec_init() is called from generic CPU::instance_finalize and some >>> archs like PowerPC call it from CPU unrealizefn. So ensure that we >>> dequeue the cpu only once. >>> >>> Instead of introducing a new field CPUState.queued, I could have used >>> CPUState.cpu_index to check if the cpu is already dequeued from the list. >>> Since that doesn't work for CONFIG_USER_ONLY, I had to add a new field. >>> >>> Signed-off-by: Bharata B Rao >> This seems reasonable to me, but I'm wondering how x86 cpu hotplug / >> unplug is working without it. > x86 hotplug/unplug code currently resides in Zhu's git tree > (git://github.com/zhugh/qemu). They are removing the CPU from the list > explicitly in x86 CPU's instance_finalize routine. Sorry, my git tree is git://github.com/zhuguihua/qemu Now there was no progress about topology, so we don't know what will happen in x86. I am not sure whether we will take this method finally. Thanks, Zhu > > Since we add CPU to the list in cpu_exec_init(), I thought it makes > sense to remove it in cpu_exec_exit(). > > May be it makes sense to separately purse this patch and the next one > so that other archs are also taken into account correctly. > > Regards, > Bharata. > > >