Re: [PATCH] x86, perf, nmi: Disable perf if counters are not accessable

Sedat Dilek
2010-11-23T15:22:17Z

Hi,

I am seeing for a while this warning in my system-wide logs:

Nov 23 11:54:14 tbox kernel: [ 0.040335] NMI watchdog failed to
create perf event on cpu0: ffffffa1

As I saw this patch from [1], I was hoping it's also fixing my problem
on an Intel Pentium-M (Banias) Single-Core CPU:

"So I changed it to:

static bool check_hw_exists(void)
{
u64 val, val_new = 0;
int ret = 0;
val = 0xabcdUL;
ret |= checking_wrmsrl(x86_pmu.perfctr, val);
ret |= rdmsrl_safe(x86_pmu.perfctr, &val_new);
if (ret || val != val_new)
return false;
return true;
}
And have applied the patch,

Thanks Don!"

Where did you apply it? Shouldn't that be in linux-2.6-tip perf/* GIT tree?

Regards,
- Sedat -

[1] http://lkml.org/lkml/2010/11/23/121
[2] http://git.kernel.org/?p=linux/kernel/git/tip/linux-2.6-tip.git;a=summary