Messages in this thread | | | From | Måns Rullgård <> | Subject | Re: [patch] perf: ARMv7 wrong "branches" generalized instruction | Date | Wed, 10 Aug 2011 20:16:17 +0100 |
| |
Vince Weaver <vweaver1@eecs.utk.edu> writes:
> On Wed, 10 Aug 2011, Will Deacon wrote: > >> > It turns out the branches event used (ARMV7_PERFCTR_PC_WRITE) only seems >> > to count taken branches. >> >> It also counts exceptions and instructions that write to the PC. > > are those more common than not-taken branches?
Every function return and every PLT call would fall in this category.
> I'd think branch predictor statistics will be a bit off if only taken > instructions are measured.
Clearly.
-- Måns Rullgård mans@mansr.com
-- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |