Re: [tip:perf/core] perf tools: Allow multiple threads or processesin record, stat, top

From: David Ahern
Date: Fri Mar 02 2012 - 09:52:21 EST


That first cup of coffee is so important.

On 3/2/12 3:56 AM, Ingo Molnar wrote:
phoenix:~> perf record -a sleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.023 MB perf.data (~988 samples) ]
phoenix:~> perf report --stdio
Warning:
The perf.data file has no samples!
# ========
# captured on: Fri Mar 2 12:01:41 2012
# hostname : phoenix
# os release : 3.3.0-rc5+
# perf version : 3.3.rc5.1698.g68a63a.dirty
# arch : x86_64
# nrcpus online : 16
# nrcpus avail : 16
# cpudesc : Quad-Core AMD Opteron(tm) Processor 8356
# cpuid : AuthenticAMD,16,2,3

Would you mind adding this patch:
https://lkml.org/lkml/2012/2/29/217
and see if it fixes your problem?

Quick test with an updated tree:
$ /tmp/pbuild/perf record -a sleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.046 MB perf.data (~1990 samples) ]

$ /tmp/pbuild/perf script
<samples dumped>

$ /tmp/pbuild/perf --version
perf version perf.core.for.mingo.36.g8eedce

This is your tip.git repository, tip/perf/core branch:

[remote "tip"]
url = git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git
fetch = +refs/heads/*:refs/remotes/tip/*
[branch "tip-perf-core"]
remote = tip
merge = refs/heads/perf/core

I did noticed that this branch only shows 3.3.0-rc2 as the latest kernel version.

# total memory : 33012240 kB
# cmdline : /home/mingo/bin/perf record -a sleep 1
# event : name = cycles, type = 0, config = 0x0, config1 = 0x0, config2 = 0x0, excl_usr = 0, excl_k
# HEADER_CPU_TOPOLOGY info available, use -I to display
# HEADER_NUMA_TOPOLOGY info available, use -I to display
# ========
phoenix:~> perf --version
perf version 3.3.rc5.1698.g68a63a.dirty
phoenix:~>

The later fixes to b52956c9, such as:

6b1bee9035d4: perf tools: fix broken perf record -a mode

did not fix this system - it's still broken as of today's -tip.

Another system running the same kernel does not exhibit this
problem, so it's somehow specific to this system.

Is the other system Intel based?

David
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/