[PATCH V2] powerpc/irq: Enable some more exceptions in /proc/interrupts interface
Anshuman Khandual
khandual at linux.vnet.ibm.com
Mon Jul 13 16:46:39 AEST 2015
On 07/13/2015 11:11 AM, Michael Ellerman wrote:
> On Mon, 2015-07-13 at 10:54 +0530, Anshuman Khandual wrote:
>> On 07/10/2015 12:40 PM, Michael Neuling wrote:
>>> What's the performance impact of this? If you run this test with --fp,
>>> --altivec or --vector what is the impact of adding this patch?
>>>
>>> http://ozlabs.org/~anton/junkcode/context_switch2.c
>>>
>>> eg
>>> ./context_switch2 --fp 0 0
>>
>> Please find the results here which looks similar with or without
>> the patch being applied.
>
> No they don't look similar with or without.
>
>> (A) Floating point context switches (context_switch2 --fp 0 0)
>
> If you just sort them you see:
>
> 316478 after
> 316540 after
> 316650 after
> 318448 after
> 318904 before
> 320216 before
> 321206 before
> 321308 before
> 323460 after
> 324596 before
>
>
> It looks like ~1% degradation. Please run the test more times (maybe 1000) and
> see how the numbers look.
Average of 1000 iterations looks better.
With the patch : 322599.57 (Average of 1000 results)
Without the patch : 320464.924 (Average of 1000 results)
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