From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:42990) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UeG13-0003nY-Sl for qemu-devel@nongnu.org; Sun, 19 May 2013 22:40:07 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UeG0y-00043f-VH for qemu-devel@nongnu.org; Sun, 19 May 2013 22:40:01 -0400 Received: from e28smtp04.in.ibm.com ([122.248.162.4]:34517) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UeG0y-00042G-Bb for qemu-devel@nongnu.org; Sun, 19 May 2013 22:39:56 -0400 Received: from /spool/local by e28smtp04.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 20 May 2013 08:04:44 +0530 Received: from d28relay05.in.ibm.com (d28relay05.in.ibm.com [9.184.220.62]) by d28dlp02.in.ibm.com (Postfix) with ESMTP id 77A12394004F for ; Mon, 20 May 2013 08:09:51 +0530 (IST) Received: from d28av05.in.ibm.com (d28av05.in.ibm.com [9.184.220.67]) by d28relay05.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r4K2dixB6488366 for ; Mon, 20 May 2013 08:09:45 +0530 Received: from d28av05.in.ibm.com (loopback [127.0.0.1]) by d28av05.in.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r4K2dmMf027959 for ; Mon, 20 May 2013 12:39:48 +1000 Message-ID: <51998CEA.6070709@linux.vnet.ibm.com> Date: Mon, 20 May 2013 10:39:38 +0800 From: Wenchao Xia MIME-Version: 1.0 References: <1366968675-1451-1-git-send-email-xiawenc@linux.vnet.ibm.com> <1366968675-1451-8-git-send-email-xiawenc@linux.vnet.ibm.com> <20130426144657.GB7648@stefanha-thinkpad.redhat.com> <20130429150541.298db151@redhat.com> <5181C9D4.4000905@linux.vnet.ibm.com> <20130502080206.21df203f@redhat.com> <51832636.1020900@linux.vnet.ibm.com> <518710E7.5060103@linux.vnet.ibm.com> <20130506092224.18dbac32@redhat.com> <5192EE9D.5030604@linux.vnet.ibm.com> <20130515082848.0ec7ca4c@redhat.com> <519442D1.8070402@linux.vnet.ibm.com> <20130516081740.6c7ee91c@redhat.com> <5195A457.9050402@linux.vnet.ibm.com> <20130517083038.3a0c1472@redhat.com> In-Reply-To: <20130517083038.3a0c1472@redhat.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Subject: Re: [Qemu-devel] [PATCH 7/7] block: dump to monitor for bdrv_snapshot_dump() and bdrv_image_info_dump() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Luiz Capitulino Cc: kwolf@redhat.com, phrdina@redhat.com, Stefan Hajnoczi , qemu-devel@nongnu.org, armbru@redhat.com, pbonzini@redhat.com 于 2013-5-17 20:30, Luiz Capitulino 写道: > On Fri, 17 May 2013 11:30:31 +0800 > Wenchao Xia wrote: > >> 于 2013-5-16 20:17, Luiz Capitulino 写道: >>> On Thu, 16 May 2013 10:22:09 +0800 >>> Wenchao Xia wrote: >>> >>>> 于 2013-5-15 20:28, Luiz Capitulino 写道: >>>>> On Wed, 15 May 2013 10:10:37 +0800 >>>>> Wenchao Xia wrote: >>>>> >>>>>> 于 2013-5-6 21:22, Luiz Capitulino 写道: >>>>>>> On Mon, 06 May 2013 10:09:43 +0800 >>>>>>> Wenchao Xia wrote: >>>>>>> >>>>>>>> 于 2013-5-3 10:51, Wenchao Xia 写道: >>>>>>>>> 于 2013-5-2 20:02, Luiz Capitulino 写道: >>>>>>>>>> On Thu, 02 May 2013 10:05:08 +0800 >>>>>>>>>> Wenchao Xia wrote: >>>>>>>>>> >>>>>>>>>>> 于 2013-4-30 3:05, Luiz Capitulino 写道: >>>>>>>>>>>> On Fri, 26 Apr 2013 16:46:57 +0200 >>>>>>>>>>>> Stefan Hajnoczi wrote: >>>>>>>>>>>> >>>>>>>>>>>>> On Fri, Apr 26, 2013 at 05:31:15PM +0800, Wenchao Xia wrote: >>>>>>>>>>>>>> @@ -2586,10 +2585,12 @@ void do_info_snapshots(Monitor *mon, const >>>>>>>>>>>>>> QDict *qdict) >>>>>>>>>>>>>> } >>>>>>>>>>>>>> >>>>>>>>>>>>>> if (total > 0) { >>>>>>>>>>>>>> - monitor_printf(mon, "%s\n", bdrv_snapshot_dump(buf, >>>>>>>>>>>>>> sizeof(buf), NULL)); >>>>>>>>>>>>>> + bdrv_snapshot_dump(NULL); >>>>>>>>>>>>>> + monitor_printf(mon, "\n"); >>>>>>>>>>>>> >>>>>>>>>>>>> Luiz: any issue with mixing monitor_printf(mon) and >>>>>>>>>>>>> monitor_vprintf(cur_mon) calls? I guess there was a reason for >>>>>>>>>>>>> explicitly passing mon instead of relying on cur_mon. >>>>>>>>>>>> >>>>>>>>>>>> where are they being mixed? >>>>>>>>>>>> >>>>>>>>>>> bdrv_snapshot_dump() used a global variable "cur_mon" inside, >>>>>>>>>>> instead >>>>>>>>>>> of let caller pass in a explicit montior* "mon", I guess that is the >>>>>>>>>>> question. >>>>>>>>>> >>>>>>>>>> I'd have to see the code to tell, but yes, what Stefan described is the >>>>>>>>>> best practice for the Monitor. >>>>>>>>>> >>>>>>>>> I think this would not be a problem until qemu wants more than one >>>>>>>>> human monitor console, and then we may require a data structure to tell >>>>>>>>> where to output the string: stdout, *mon, or even stderr, and >>>>>>>>> error_printf() also need to be changed. >>>>>>>>> >>>>>>>> Luiz, what is your idea? I'd like to respin v2 if no issues for it. >>>>>>> >>>>>>> As I said before, I'd have to see the code to tell. But answering your comment, >>>>>>> the code does support multiple monitors. >>>>>>> >>>>>> Hi Luiz, >>>>>> Sorry to ask again, do you think method above is OK now, waiting for >>>>>> your confirm. >>>>> >>>>> Can you point me to the code in question? >>>>> >>>> Sure, it is >>>> >>>> + >>>> +/* >>>> + * Print to current monitor if we have one, else to stdout. It is >>>> similar with >>>> + * error_printf(). >>>> + * TODO just like error_vprintf() >>>> + */ >>>> +void message_printf(const char *fmt, ...) >>>> +{ >>>> + va_list ap; >>>> + >>>> + va_start(ap, fmt); >>>> + if (cur_mon) { >>>> + monitor_vprintf(cur_mon, fmt, ap); >>>> + } else { >>>> + vfprintf(stdout, fmt, ap); >>>> + } >>>> + va_end(ap); >>>> +} >>>> >>>> This function used global variable cur_mon instead of input parameter, >>>> similar to error_printf(). >>> >>> Why do you need it? Why can't you you use error_printf() for example? >>> >> error_printf() will print out to stderr in qemu-img, but stdout is >> wanted for those dump info function. > > You can refactor the code so that you can pass a FILE *stream argument to > error_vprintf() and maybe add error_printf_stream()? > The name is a bit confusing, maybe qemu_printf()? Another problem is, monitor have a buf[] instead of a FILE*, I think it need a structure include those: typdef enum QemuOutputType { QEMU_OUTPUT_TYPE_STREAM, QEMU_OUTPUT_TYPE_MONITOR, } QemuOutputType; typedef struct QemuOutput { QemuOutputType type; union { FILE *file; Monitor *mon; }; } It may brings some inconvienience to caller, but this is what I can think out now. -- Best Regards Wenchao Xia