Re: perf top -z not working?

[Ryan Johnson <ryan.johnson@cs.utoronto.ca>]

On 22/10/2012 9:12 AM, David Ahern wrote:
> On 10/22/12 5:50 AM, Ryan Johnson wrote:
>>>>> It seems that `perf top -z' does not behave as advertized, at
>>>>> least not on the 3.2.0-25 kernel (Ubuntu) that I'm running. The
>>>>> man page states that it should "zero history across display
>>>>> updates" but the counts still seem to accumulate (the total
>>>>> samples reported rises monotonically) and processes still show up
>>>>> in the display long after they have exited. Pressing `z' or `Z'
>>>>> seems to have no effect, either.
>>> Are you using the --tui or --stdio interface? Try with both and 
>>> check if
>>> it works in one of them, I bet the problem is with --tui.
>> --stdio does the same, so I'll have to try updating my kernel like
>> Chulmin suggested (haven't had time to do that yet)
>
> The kernel has nothing to do with the feature. From builtin-top.c, 
> this part is either not happening or more likely not happening correctly.
>
>     if (top->zero)
>         symbol__annotate_zero_histogram(symbol, top->sym_evsel->idx);
>     else
>         symbol__annotate_decay_histogram(symbol, top->sym_evsel->idx);
>
> I recall it working recently - last year or so. Can you try different 
> versions -- say 3.0, 3.2, 3.4 and latest? If you have a copy of Linus' 
> tree or Arnaldo's git tree it should not take much time.
Chulmin says his 3.0 version works. My 3.2.18 doesn't. I don't have a 
copy of the git tree on that machine, but I'll try building 3.4.x and 
tip when I get a chance. I have never built perf-tools before, though, 
so I'd appreciate tips on what might be different for building 
perf-tools compared to the kernel, and how to avoid building the 
standard kernel along the way. Hopefully it's just configure-make-install?

Regards,
Ryan