From mboxrd@z Thu Jan  1 00:00:00 1970
From: fche@redhat.com (Frank Ch. Eigler)
Subject: Re: timing information with perf
Date: Mon, 16 Nov 2015 13:08:15 -0500
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In-Reply-To: <94D0C06D-C3A7-4BD1-9898-124EE0AA923D@netapp.com> (Olga Kornievskaia's message of "Thu, 12 Nov 2015 21:07:20 +0000")
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To: "Kornievskaia, Olga" <Olga.Kornievskaia@netapp.com>
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Olga.Kornievskaia wrote:

> [...] say there are two tracepoints =FCfoobar_enter=FD and
> =FCfoobar_exit=FD. Each tracepoint logs a timestamp. I=F9d like to be=
 able
> to say that on average it takes that many time-units between =FCenter=
=FD
> and =FCexit=FD tracepoints. [...]

=46or completeness, a complete systemtap implementation of this could l=
ook like:

# stap -e '
   global s, t%
   probe kernel.trace("foobar_enter") {
       t[tid()]=3Dgettimeofday_us()=20
   }
   probe kernel.trace("foobar_exit") {
       if (tid() in t) { s <<< gettimeofday_us() - t[tid()] }=20
   }
   probe timer.s(5),end {
       printf("cumulative average us: %d\n", @avg(s))=20
   }=20
'


- FChE