Messages in this thread | | | From | Namhyung Kim <> | Subject | Re: [BUG] perf top: -z option does not work | Date | Tue, 12 Aug 2014 17:09:17 +0900 |
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Hi Stephane,
On Tue, 12 Aug 2014 06:44:34 +0200, Stephane Eranian wrote: > Hi, > > > My understanding is that the -z option is used to only print a profile > since the last refresh. So if I have a refresh of 5s, then it prints the profile > based on the samples accumulated over the last 5 seconds.
Yep, that's what I understand about the -z behavior too.
> > The Z mode used to be available interactively. Nowadays, it seems only > avail from the cmdline. But it does not work.
Hmm.. it seems the stdio supports 'z' key but TUI don't.
> > I run a simple test. > $ sudo perf top -z > > Then for 5s I run a cycle-burning noploop program. > It shows up at the top. But when it terminates, the program still stays > at the top of the profile for a long time. This is not what I'd expect. > The noploop line should disappear in the next couple of refreshes after > the program has terminated. > > I am using tip.git and seeing the problem. But it seems, it's been there for a > long time. > > Any idea what's wrong?
Looking at the code, it only zero out the annotation info but hist entries. I guess we need to check the flag and throw out existing entries instead of decaying.
Also I wonder about the order of decaying - shouldn't it be decayed before processing current entries? It seems current code processes current entries first and then decays...
I'll prepare patches for this soon.
Thanks, Namhyung
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