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?
- 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