profiling functions called in interrupt context

[Nuno Martins]

On Tue, Sep 20, 2011 at 5:59 AM, Amit Nagal <helloin.amit at gmail.com> wrote:

> On Tue, Sep 20, 2011 at 10:25 AM, rohan puri <rohan.puri15 at gmail.com>
> wrote:
> >
> >
> > On Tue, Sep 20, 2011 at 10:13 AM, Amit Nagal <helloin.amit at gmail.com>
> wrote:
> >>
> >> On Tue, Sep 20, 2011 at 10:05 AM, rohan puri <rohan.puri15 at gmail.com>
> >> wrote:
> >> >
> >> >
> >> > On Tue, Sep 20, 2011 at 9:44 AM, Amit Nagal <helloin.amit at gmail.com>
> >> > wrote:
> >> >>
> >> >> Hi ,
> >> >>
> >> >> i want to measure time spend in a callback function called from
> >> >> interrupt context .
> >> >> since the time spend will be in us / ns , what kernel apis can i use
> >> >> to measure it ?
> >> >>
> >> >> also since i want to use it in interrupt context  , kernel time
> >> >> measurement apis should not sleep .
> >> >> i am using embedded arm target , and tools like OProfile  are not
> >> >> available .
> >> >>
> >> >> can i be guided which  kernel time measurement apis shall i use to
> >> >> measure time in a interrupt callback ?
> >> >>
> >> >> Regards
> >> >> Amit Nagal
> >> >
> >> > For this you can make use of ftrace.
> >> >
> >> > Refer link
> http://www.mjmwired.net/kernel/Documentation/trace/ftrace.txt
> >> >
> >> > Regards,
> >> > Rohan
> >> >
> >>
> >> Tools like ftrace are not available to me in my embedded arm target .
> >> So i want to use kernel apis to deal with time measurement in
> >> interrupt context .
> >>
> >> Regards
> >> Amit Nagal
> >
> > Hi Amit,
> >
> > I think ftrace can be enabled and used on arm arch.
> > Please Refer http://www.omappedia.org/wiki/Installing_and_Using_Ftrace
> >
> > Regards,
> > Rohan
> >
>
> Ok ,  thanks for the link . i will try the same .
>

Couldn't use ktimer, it says that is a high resolution timer inside the
kernel, you could combine ktimer with kretprobe (you assing a function prior
to the calling of your function and another when finished ). It is a
instrumentation method inside the kernel.




>
> Regards
> Amit Nagal
>
> _______________________________________________
> Kernelnewbies mailing list
> Kernelnewbies at kernelnewbies.org
> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
>



-- 
Nuno Martins
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.kernelnewbies.org/pipermail/kernelnewbies/attachments/20110920/b013755e/attachment.html