Re: timing information with perf

[fche@redhat.com (Frank Ch. Eigler)]

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain; charset=utf-8, Size: 677 bytes --]


Olga.Kornievskaia wrote:

> [...] say there are two tracepoints üfoobar_enterý and
> üfoobar_exitý. Each tracepoint logs a timestamp. Iùd like to be able
> to say that on average it takes that many time-units between üenterý
> and üexitý tracepoints. [...]

For completeness, a complete systemtap implementation of this could look like:

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


- FChE