Re: [BUG] perf sched broken

Stephane Eranian
2011-01-12T22:38:17Z

On Wed, Jan 12, 2011 at 11:35 PM, Corey Ashford
<cjashfor@linux.vnet.ibm.com> wrote:
> On 01/12/2011 01:29 AM, Stephane Eranian wrote:
>>
>> 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.
>
> I'm currently using the master branch of
> git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip.git
>
> Without your :r patch, I do see the problem with the :r modifier, but this
> sequence
>
> $ 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
>
> is working fine for me.  I even removed /usr/bin from my search path to make
> sure /usr/bin/perf wasn't getting found during the run of ./perf.
>
> I am running on a different environment than you, though.  I am using Fedora
> 14 (2.6.35 kernel).
>
Maybe that's the problem. I was trying this on 2.6.37-tip.

> For the record, this is what I see:
> [root@oc7708135540 perf]# ./perf report -D
> WARNING: No sample_id_all support, falling back to unordered processing
>
> 0x100 [0x40]: event: 1
> .
> . ... raw event: size 64 bytes
> .  0000:  01 00 00 00 01 00 40 00 ff
>  ff ff ff 00 00 00 00  ...
> ...@.........
> .  0010:  00 00 00 00 00 00 00 00 ff
>  ff ff 9f ff ff ff ff  ...
> .............
> .  0020:  00 00 00 81 ff ff ff ff 5b
>  6b 65 72 6e 65 6c 2e  ...
> .....[kernel.
> .  0030:  6b 61 6c 6c 73 79 6d 73 5d
>  5f 74 65 78 74 00 00  kal
> lsyms]_text..
> .
> -1 -1 0x100 [0x40]: PERF_RECORD_MMAP -1/0: [0(0xffffffff9fffffff) @
> 0xffffffff81000000]: [kernel
> .kallsyms]_text
>
> 0x140 [0x38]: event: 1
> .
> . ... raw event: size 56 bytes
> .  0000:  01 00 00 00 01 00 38 00 ff
>  ff ff ff 00 00 00 00  ...
> ...8.........
> .  0010:  00 00 00 a0 ff ff ff ff ff
>  2f 00 00 00 00 00 00  ...
> ....../......
> .  0020:  00 00 00 00 00 00 00 00 5b
>  6f 75 74 70 75 74 5d  ...
> .....[output]
> .  0030:  00 00 00 00 00 00 00 00
>                        ...
> .....
> .
> -1 -1 0x140 [0x38]: PERF_RECORD_MMAP -1/0: [0xffffffffa0000000(0x2fff) @ 0]:
> [output]
>
> .. and so on ..
>
>
> I will look into the :r problem now.
>
> - Corey
>