From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53491) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1azilI-0003Jh-FQ for qemu-devel@nongnu.org; Mon, 09 May 2016 06:50:05 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1azilC-0006DF-Cc for qemu-devel@nongnu.org; Mon, 09 May 2016 06:50:03 -0400 Received: from [59.151.112.132] (port=64604 helo=heian.cn.fujitsu.com) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1azilA-00066X-Ak for qemu-devel@nongnu.org; Mon, 09 May 2016 06:49:58 -0400 References: <1460977906-25218-1-git-send-email-zhangchen.fnst@cn.fujitsu.com> <1460977906-25218-2-git-send-email-zhangchen.fnst@cn.fujitsu.com> <5721B379.5080809@redhat.com> <5721B8D0.3030700@redhat.com> <5721C1E8.4040409@cn.fujitsu.com> <5721C6FE.6050301@redhat.com> <5721D21C.6070202@cn.fujitsu.com> <5722C0D6.8080805@redhat.com> <572C2EB4.1090005@cn.fujitsu.com> <572C3BAF.5080106@redhat.com> From: Zhang Chen Message-ID: <57306B3C.5090000@cn.fujitsu.com> Date: Mon, 9 May 2016 18:49:32 +0800 MIME-Version: 1.0 In-Reply-To: <572C3BAF.5080106@redhat.com> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 8bit Subject: Re: [Qemu-devel] [RFC PATCH V3 1/4] colo-compare: introduce colo compare initlization List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jason Wang , qemu devel Cc: zhanghailiang , Li Zhijian , Gui jianfeng , "eddie.dong" , "Dr. David Alan Gilbert" , Yang Hongyang > + > + s->chr_sec_in = qemu_chr_find(s->sec_indev); > + if (s->chr_sec_in == NULL) { > + error_setg(errp, "Secondary IN Device '%s' not found", > + s->sec_indev); > + return; > + } > + > + s->chr_out = qemu_chr_find(s->outdev); > + if (s->chr_out == NULL) { > + error_setg(errp, "OUT Device '%s' not found", s->outdev); > + return; > + } > + > + qemu_chr_fe_claim_no_fail(s->chr_pri_in); > + qemu_chr_add_handlers(s->chr_pri_in, compare_chr_can_read, > + compare_pri_chr_in, NULL, s); > + > + qemu_chr_fe_claim_no_fail(s->chr_sec_in); > + qemu_chr_add_handlers(s->chr_sec_in, compare_chr_can_read, > + compare_sec_chr_in, NULL, s); > + >>>>>>> Btw, what's the reason of handling this in main loop? I thought it >>>>>>> would >>>>>>> be better to do this in colo thread? Otherwise, you need lots of >>>>>>> extra >>>>>>> synchronizations? >>>>>> Do you mean we should start/stop/do checkpoint it by colo-frame? >>>>> I mean we probably want to handle pri_in and sec_in in colo compare >>>>> thread. Through this way, there's no need for extra synchronization >>>>> with >>>>> main loop. >>>> I get your point, but how to do this. >>>> Now, we use qemu_chr_add_handlers to do this job. >>> You probably want to start a new main loop in colo comparing thread. >> >> IIUC, do you mean >> - remove char device read_handler >> >> ↓at colo comparing thread↓ >> while (true) { >> - blocking read packet from char device with select(2)/poll(2)... >> - compare packet >> } > Yes, something like this. > But remove qemu_chr_add_handlers I can't get fd to select/poll. How to get fd from all kinds of chardev? Thanks Zhang Chen >> This solution will lead comparing packet and reading packet in serial. >> But i don't know if this will have a good performance. > This probably won't have the best performance but it simplify lots of > things. Actually doing it in main loop will slow down all other I/O > processing. Consider colo can only handling userspace network traffic > now, we could start from this. For performance, it needs lots of other > stuff: I think the most important thing is to add vhost support. > > Thanks > >>>> Thanks >>>> zhangchen >>> >>> . >>> > > > . > -- Thanks zhangchen