Messages in this thread |  | | Date | Sun, 06 Jan 2013 20:48:36 -0700 | From | David Ahern <> | Subject | Re: 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
|  |