Re: PEBS (in perf) stopped working from 3.6 -> 3.7

From: David Ahern
Date: Sun Jan 06 2013 - 22:48:30 EST

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:

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).

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at