Re: [BUG] perf sched broken

[Corey Ashford]

On 01/12/2011 04:11 AM, Arnaldo Carvalho de Melo wrote:
> Em Wed, Jan 12, 2011 at 10:29:05AM +0100, Stephane Eranian escreveu:
> > Hi,
> >
> > I am trying to use perf sched from tip-x86 but it fails for all my attempts.
> >
> > First of, I think the event list is stale. This is not so much the
> > events themselves
> > but rather the flags.
> >
> > Looks to me like the :r modifier is not supported anymore, so a patch like the
> > one below is needed. That helps collect a trace. But then, you can dump
> > the trace.
>
> I got to this point as well, and reverting 4c635a4 did the trick for me,
> Corey, this is another report for that problem, can you take a look at
> it? Stephane, can you try doing a:
>
> git show 4c635a4 | patch -p1 -R
>
> To see if the problem is fixed?

I will have a look at this now.  Thanks for the report.

- Corey

> - Arnaldo
>
> > $ perf sched rec dd if=/dev/zero of=/dev/null count=1000000
> > 1000000+0 records in
> > 1000000+0 records out
> > 512000000 bytes (512 MB) copied, 0.589981 s, 868 MB/s
> > [ perf record: Woken up 1 times to write data ]
> > [ perf record: Captured and wrote 0.481 MB perf.data (~20997 samples) ]
> >
> > $ perf sched rep
> > run measurement overhead: 2934 nsecs
> > sleep measurement overhead: 90502 nsecs
> > the run test took 999149 nsecs
> > the sleep test took 1092248 nsecs
> >    Fatal: no trace data in the file
> >
> > $ perf sched trace -D
> >   usage: perf sched [<options>] {record|latency|map|replay|trace}
> >
> >      -i, --input<file>     input file name
> >      -v, --verbose         be more verbose (show symbol address, etc)
> >      -D, --dump-raw-trace  dump raw trace in ASCII
> >
> > Note that this is not specific to pref sched. If I use perf record directly,
> > I run into the same issue:
> > $ perf record -R -a -c 1 -e sched:sched_switch -- sleep 1
> > [ perf record: Woken up 1 times to write data ]
> > [ perf record: Captured and wrote 0.365 MB perf.data (~15962 samples) ]
> > $./perf report -D
> >    Fatal: no trace data in the file
> >
> > Now that perf trace is gone, how to I dump the trace?
>
> Good question, checking this s/trace/script/g fallout.
>
> - Arnaldo

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