Re: [RFC] perf script: callchain handling is not useful
From: Arnaldo Carvalho de Melo
Date: Wed Aug 29 2018 - 09:54:52 EST
Em Tue, Aug 28, 2018 at 07:41:31PM -0700, Stephane Eranian escreveu:
> I am doing the following simple collection with callchain and load profiling:
> $ perf record -g -d -e cpu/event=0xd0,umask=0x81/pp my_test_program
> But when I type:
> $ perf script -F ip,addr
> I also see the callchain and it is not clear which is the IP. Further
> more parsing becomes more difficult because of multiple lines per
> sample. I understand that multiline is likely because of
> symbolization. But if I don't want symbolization, it should be
> possible to print all in one line.
Humm, to have this not break possibly existing scripts, perhaps we can
have something like:
$ perf script -F ip,-callchain,addr
And if asked explicitely for the callchain, then it gets added in the
> The current output is not very useful. You expect perf script to give
> you one line per sample and only what you want. Callchain != IP.
> I think the following should happen:
> - do not print callchain when asked for the IP. Create a callchain filter.
> - print callchain on the same line, much like what is done for brstack
> It is not clear to me why callchain and ip were lumped together.
> Any opinion on my proposal?