Re: [patch] perf: ARMv7 wrong "branches" generalized instruction
From: Måns Rullgård
Date: Wed Aug 10 2011 - 15:16:32 EST
Vince Weaver <vweaver1@xxxxxxxxxxxx> 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.
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/