Re: What is the performance when using frame pointers in the kernel?

[Andi Kleen]

Jiri Kosina <jkosina@xxxxxxx> writes:

> On Thu, 3 Dec 2009, Peter Zijlstra wrote:
>
>> > What is the performance hit when the kernel is compiled with frame 
>> > pointers?
>> 
>> build both kernels and run your favourite workload to find out.
>
> But generally speaking, frame pointers impose quite some performance 
> penalty indeed. lmbench syscall microbenchmark can give you some hint. I 
> expect you'll see approx. 10% performance increase for various syscalls if 
> you disable them, as that's what we have measured lately.

It'll depend on the CPU. On many common cores frame pointer cause
a a few cycles stall on each function entry, but not on all.

-Andi

-- 
ak@xxxxxxxxxxxxxxx -- Speaking for myself only.
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