profiling functions called in interrupt context

[anish singh]

On Tue, Sep 20, 2011 at 4:11 PM, Nuno Martins
<nuno.m.g.martins at gmail.com> wrote:
>
>
> 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.
kernel/Documentation/kprobes.txt
>
>
>>
>> Regards
>> Amit Nagal
>>
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>
>
>
> --
> Nuno Martins
>
>
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