Messages in this thread | | | Date | Mon, 22 Dec 2014 17:33:20 +0900 | From | Masami Hiramatsu <> | Subject | Re: Merge ftrace data of host and guest |
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Hi,
I'm working on trace-cmd virt-server feature. This is just a basic feature to allow trace-cmd using virtio-trace (no time synchronizing). I'll send the updated version of the series soon.
(2014/12/22 16:07), Divya Vyas wrote: > 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 .
Right, to complete this work we need trace-merge like merging feature. I assume that we can do that by passing the offset of the timestamp information with guest trace data (that is the simplest implementation).
However, currently trace-merge depends on x86 TSC, but some intel processors TSC is not stable. That is current barrier of trace-merge.
Thank you,
> > 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@gmail.com> 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@goodmis.org> 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 >>> >
-- Masami HIRAMATSU Software Platform Research Dept. Linux Technology Research Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: masami.hiramatsu.pt@hitachi.com
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