Re: [perfmon] Re: [perfmon2] perfmon2 merge news

[David Miller]

From: Andi Kleen <andi@xxxxxxxxxxxxxx>
Date: Wed, 14 Nov 2007 13:38:38 +0100

> At least for x86 and I suspect some 1other architectures we don't
> initially need a syscall at all for this. There is an instruction
> RDPMC who can read a performance counter just fine. It is also much
> faster and generally preferable for the case where a process measures
> events about itself. In fact it is essential for one of the use cases
> I would like to see perfmon used (replacement of RDTSC for cycle
> counting) 

I wouldn't even want to use a syscall for something like
that on Sparc, I'd rather give this a dedicated software
trap so that I can code it completely in assembler.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/