Re: [PATCH 1/2] perf evsel: Fix probing of precise_ip level for default cycles event

From: Arnaldo Carvalho de Melo
Date: Wed Jun 14 2017 - 15:12:39 EST


Em Wed, Jun 14, 2017 at 04:06:01PM +0200, Ingo Molnar escreveu:
> * Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> wrote:
> > Em Wed, Jun 14, 2017 at 07:45:01AM +0200, Ingo Molnar escreveu:
> > > triton:~/tip> perf report --stdio
> > > unwind: target platform=x86 is not supported

> so it's a maximum-features build, right?

looks like

> Here's the unwind libraries:
>
> triton:~/tip> dpkg -l | grep unwind
> ii libunwind-dev 1.1-4.1ubuntu2 amd64 library to determine the call-chain of a program - development
> ii libunwind8 1.1-4.1ubuntu2 amd64 library to determine the call-chain of a program - runtime
> ii libunwind8-dev 1.1-4.1ubuntu2 amd64 library to determine the call-chain of a program - development

> libunwind-dev is installed it appears.

> Let me know if you want me to run other tests.

Couldn't reproduce so far :-\ I am trying it on a docker container with
Ubuntu 16.04, is that the version you're using, seems to be the 16.04,
at least the packages above listed are the same as in my container...

Also it would be nice to see if this is something introduced by Jiada's
patch:

Author: Jiada Wang <jiada_wang@xxxxxxxxxx>
Date: Sun Apr 9 20:02:37 2017 -0700

perf tools: Fix build with ARCH=x86_64

---------------------------

I.e. the other patch in my perf/urgent branch, does this warning go
away if you apply just the first patch in my perf/urgent branch as of
now?

Here is my testing:

root@5754d7c06d56:/# perf record -F 10000 --call-graph dwarf sleep 5
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.118 MB perf.data (14 samples) ]
root@5754d7c06d56:/# perf report --stdio --dsos '[kernel.kallsyms]' 2>&1 | head -20
# To display the perf.data header info, please use --header/--header-only options.
#
# dso: [kernel.kallsyms]
#
# Total Lost Samples: 0
#
# Samples: 14 of event 'cycles:ppp'
# Event count (approx.): 1085705
#
# Children Self Command Symbol
# ........ ........ ....... ..............................
#
28.16% 0.00% sleep [k] page_fault
|
---page_fault
do_page_fault
__do_page_fault
handle_mm_fault
|
|--17.82%--__handle_mm_fault
root@5754d7c06d56:/# grep Ubuntu /etc/os-release
NAME="Ubuntu"
PRETTY_NAME="Ubuntu 16.04.2 LTS"
root@5754d7c06d56:/#

- Arnaldo

- Arnaldo