[PATCH v10 00/25] Speculative page faults

[Punit Agrawal]

Hi Laurent,

Thanks for your reply.

Laurent Dufour <ldufour at linux.vnet.ibm.com> writes:

> On 02/05/2018 16:17, Punit Agrawal wrote:
>> Hi Laurent,
>> 
>> One query below -
>> 
>> Laurent Dufour <ldufour at linux.vnet.ibm.com> writes:
>> 
>> [...]
>> 
>>>
>>> Ebizzy:
>>> -------
>>> The test is counting the number of records per second it can manage, the
>>> higher is the best. I run it like this 'ebizzy -mTRp'. To get consistent
>>> result I repeated the test 100 times and measure the average result. The
>>> number is the record processes per second, the higher is the best.
>>>
>>>   		BASE		SPF		delta	
>>> 16 CPUs x86 VM	12405.52	91104.52	634.39%
>>> 80 CPUs P8 node 37880.01	76201.05	101.16%
>> 
>> How do you measure the number of records processed? Is there a specific
>> version of ebizzy that reports this? I couldn't find a way to get this
>> information with the ebizzy that's included in ltp.
>
> I'm using the original one : http://ebizzy.sourceforge.net/

Turns out I missed the records processed in the verbose output enabled
by "-vvv". Sorry for the noise.

[...]

>> 
>> A trial run showed increased fault handling when SPF is enabled on an
>> 8-core ARM64 system running 4.17-rc3. I am using a port of your x86
>> patch to enable spf on arm64.
>> 
>> SPF
>> ---
>> 
>> Performance counter stats for './ebizzy -vvvmTRp':
>> 
>>          1,322,736      faults                                                      
>>          1,299,241      software/config=11/                                         
>> 
>>       10.005348034 seconds time elapsed
>> 
>> No SPF
>> -----
>> 
>>  Performance counter stats for './ebizzy -vvvmTRp':
>> 
>>            708,916      faults
>>                  0      software/config=11/
>> 
>>       10.005807432 seconds time elapsed
>
> Thanks for sharing these good numbers !


A quick run showed 71041 (no-spf) vs 122306 (spf) records/s (~72%
improvement).

I'd like to do some runs on a slightly larger system (if I can get my
hands on one) to see how the patches behave. I'll also have a closer
look at your series - the previous comments were just somethings I
observed as part of trying the functionality on arm64.

Thanks,
Punit