lkml.org 
[lkml]   [2013]   [Jan]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: PEBS (in perf) stopped working from 3.6 -> 3.7
On 1/4/13 6:05 PM, Steinar H. Gunderson wrote:
> On Fri, Jan 04, 2013 at 05:16:27PM -0700, David Ahern wrote:
>> Known problem. Pick one of: update perf to 3.7, add H to the command
>> (-e cycles:ppH) or apply this patch:
>> https://lkml.org/lkml/2012/12/28/384
>
> I spoke too soon. This works for cycles, but not for branch-misses:
>
> pannekake:~> sudo perf record -e branch-misses:ppH -a
>
> Error: sys_perf_event_open() syscall returned with 95 (Operation not supported) for event branch-misses:ppH. /bin/dmesg may provide additional information.
>
> No hardware sampling interrupt available. No APIC? If so then you can boot the kernel with the "lapic" boot parameter to force-enable it.
>
> Why would the two be different?

I will make a guess that is processor dependent. On an E5540 with
3.4.11-1.fc16.x86_64, 3.6.10-2.fc16.x86_64, and 3.8 I get the same
failure message.

But on a E5620, it works fine with 3.4 and 3.7 (no intermediate kernels
on that box).

David


\
 
 \ /
  Last update: 2013-01-07 05:21    [W:0.040 / U:0.844 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site