[lkml]   [2005]   [Nov]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [Perfctr-devel] Re: Enabling RDPMC in user space by default
On Tue, 2005-11-29 at 19:13 +0100, Andi Kleen wrote:
> > Where did you see that PMC0 (PERSEL0/PERFCTR0) can only be programmed
> > to count cpu cycles (i.e. cpu_clk_unhalted)? As far as I can tell from
> > the documentation, the 4 counters are symetrical and can measure
> > any event that the processor offers.
> Linux NMI watchdog does that.
> All other perfctr users are supposed to keep their fingers away
> from the watchdog (it looks like oprofile doesn't but not for much
> longer ...)

Why? Hardcoding PMC 0 to be a cycle counter seems to be a waste of a
perfectly usable performance counter. What if I want to profile four
things, none of them requiring a cycle count?

Nicholas Miell <>

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

 \ /
  Last update: 2005-11-29 22:45    [W:0.080 / U:0.884 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site