Re: Merge ftrace data of host and guest

From: Divya Vyas
Date: Mon Dec 22 2014 - 02:08:18 EST


Hi ,

One more thing I want to add that Yoshihiro YUNOMAE's trace-merge
script does this time synchronization. We have to calculate guest
offset and then subtract with host time .

But it is not applying on current trace-cmd report output format and
not giving desired output .

Thanks,
Divya Vyas

On Mon, Dec 22, 2014 at 12:34 PM, Divya Vyas <edivya.vyas@xxxxxxxxx> wrote:
> Hi Steven,
>
> I am sorry but I am very new to trace-cmd , that's why I didn't knew
> what you are working on it.
>
> I will explain you whole scenario , Actually I have multiple guests
> and a host and I want to see all traces on a single file with
> trace-cmd report command and may be kernelshark also .
>
> trace-cmd report -i guest.dat -i host.dat command is giving me all
> traces is single file but the timestamp is different for guest . So
> the challenge for me is to sync the timestamp of guest and host . Can
> you advise me something in this ? How can I sync gettimeofday clocks
> of guest and host ?
>
> and kernelshark doesnt take trace-cmd report input , I think it takes
> guest.dat and host.dat .
> Is there any other viewer available for ftrace ?
>
>
>
>
>
>
> On Sat, Dec 20, 2014 at 10:40 AM, Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
>> On Fri, Dec 19, 2014 at 05:52:52PM +0530, Divya Vyas wrote:
>>> Hi,
>>
>> Hi, it would be helpful if you Cc'd me. I would have responded quicker. Luckily,
>> someone noticed this email and told me about it.
>>
>>>
>>> I think it is not desired output . Ths script is written for diffrent
>>> format .ftrace format is ( trace-cmd report command generates) :
>>
>> I'm actually working on trace-cmd this week and hopefully I'll be able to release
>> 2.5 by x-mas.
>>
>> I believe that Masami is going to start continuing work on the virt guest
>> tracer for trace-cmd.
>>
>> Also, for now, for a crud way of merging, if both the gettimeofday clocks
>> of the host and guest are synced, you could do:
>>
>> guest> trace-cmd record -o guest.dat --date ...
>>
>> host> trace-cmd record -o host.dat --date ...
>>
>> and then run:
>>
>> trace-cmd report -i guest.dat -i host.dat
>>
>> and trace-cmd will merge the two. The --date will add a way to sync the trace
>> timestamps to a wall clock and that will be used to try to interleave the
>> events of both the data files.
>>
>> -- Steve
>>
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