2012-10-22 오후 11:10, Ryan Johnson 쓴 글:

On 22/10/2012 9:12 AM, David Ahern wrote:

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On 10/22/12 5:50 AM, Ryan Johnson wrote:

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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?

How about checking your "top" version first?

According to David's suggestion, it is the matter of top version.

Mine was 3.2.8. (top --version).

Regards,
Ryan