From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:39183) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b0kQY-0005NP-Qu for qemu-devel@nongnu.org; Thu, 12 May 2016 02:48:56 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1b0kQV-0005rb-Gg for qemu-devel@nongnu.org; Thu, 12 May 2016 02:48:54 -0400 Received: from [59.151.112.132] (port=13063 helo=heian.cn.fujitsu.com) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b0kQT-0005m6-Qx for qemu-devel@nongnu.org; Thu, 12 May 2016 02:48:51 -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> <57306B3C.5090000@cn.fujitsu.com> From: Zhang Chen Message-ID: <5734275C.8070406@cn.fujitsu.com> Date: Thu, 12 May 2016 14:49:00 +0800 MIME-Version: 1.0 In-Reply-To: <57306B3C.5090000@cn.fujitsu.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 On 05/09/2016 06:49 PM, Zhang Chen wrote: > >> + >> + 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? > Hi~ jason. If we use chardev socket the fd save in QIOChannelSocket. and if we use chardev file the fd save in QIOChannelFile. Have any common method to get fd? > 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