From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46304) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ayZOq-0003dr-0f for qemu-devel@nongnu.org; Fri, 06 May 2016 02:38:14 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ayZOe-0004Aj-2a for qemu-devel@nongnu.org; Fri, 06 May 2016 02:38:02 -0400 Received: from mx1.redhat.com ([209.132.183.28]:49336) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ayZOd-00047a-RA for qemu-devel@nongnu.org; Fri, 06 May 2016 02:37:56 -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> From: Jason Wang Message-ID: <572C3BAF.5080106@redhat.com> Date: Fri, 6 May 2016 14:37:35 +0800 MIME-Version: 1.0 In-Reply-To: <572C2EB4.1090005@cn.fujitsu.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable 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: Zhang Chen , qemu devel Cc: zhanghailiang , Li Zhijian , Gui jianfeng , "eddie.dong" , "Dr. David Alan Gilbert" , Yang Hongyang On 05/06/2016 01:42 PM, Zhang Chen wrote: > > > On 04/29/2016 10:03 AM, Jason Wang wrote: >> >> On 04/28/2016 05:04 PM, Zhang Chen wrote: >>> >>> On 04/28/2016 04:17 PM, Jason Wang wrote: >>>> On 04/28/2016 03:55 PM, Zhang Chen wrote: >>>>> On 04/28/2016 03:16 PM, Jason Wang wrote: >>>>>> On 04/28/2016 02:53 PM, Jason Wang wrote: >>>>>>> +static void compare_set_outdev(Object *obj, const char *value, >>>>>>> Error **errp) >>>>>>>> +{ >>>>>>>> + CompareState *s =3D COLO_COMPARE(obj); >>>>>>>> + >>>>>>>> + g_free(s->outdev); >>>>>>>> + s->outdev =3D g_strdup(value); >>>>>>>> +} >>>>>>>> + >>>>>>>> +/* >>>>>>>> + * called from the main thread on the primary >>>>>>>> + * to setup colo-compare. >>>>>>>> + */ >>>>>>>> +static void colo_compare_complete(UserCreatable *uc, Error >>>>>>>> **errp) >>>>>>>> +{ >>>>>>>> + CompareState *s =3D COLO_COMPARE(uc); >>>>>>>> + >>>>>>>> + if (!s->pri_indev || !s->sec_indev || !s->outdev) { >>>>>>>> + error_setg(errp, "colo compare needs 'primary_in' ," >>>>>>>> + "'secondary_in','outdev' property set"); >>>>>>>> + return; >>>>>>>> + } else if (!strcmp(s->pri_indev, s->outdev) || >>>>>>>> + !strcmp(s->sec_indev, s->outdev) || >>>>>>>> + !strcmp(s->pri_indev, s->sec_indev)) { >>>>>>>> + error_setg(errp, "'indev' and 'outdev' could not be >>>>>>>> same " >>>>>>>> + "for compare module"); >>>>>>>> + return; >>>>>>>> + } >>>>>>>> + >>>>>>>> + s->chr_pri_in =3D qemu_chr_find(s->pri_indev); >>>>>>>> + if (s->chr_pri_in =3D=3D NULL) { >>>>>>>> + error_setg(errp, "Primary IN Device '%s' not found", >>>>>>>> + s->pri_indev); >>>>>>>> + return; >>>>>>>> + } >>>>>>>> + >>>>>>>> + s->chr_sec_in =3D qemu_chr_find(s->sec_indev); >>>>>>>> + if (s->chr_sec_in =3D=3D NULL) { >>>>>>>> + error_setg(errp, "Secondary IN Device '%s' not found", >>>>>>>> + s->sec_indev); >>>>>>>> + return; >>>>>>>> + } >>>>>>>> + >>>>>>>> + s->chr_out =3D qemu_chr_find(s->outdev); >>>>>>>> + if (s->chr_out =3D=3D 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 > > =E2=86=93at colo comparing thread=E2=86=93 > while (true) { > - blocking read packet from char device with select(2)/poll(2)... > - compare packet > } Yes, something like this. > > 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 >> >> >> . >> >