[Scst-devel] [ofa-general] SRP/mlx4 interrupts throttling performance

[Cameron Harr]

Cameron Harr wrote:
> Vladislav Bolkhovitin wrote:
>>>>> I ran each test 3 times and took the averages. In order to get a 
>>>>> quick look at performance per run, I added a column in the summary 
>>>>> that sums the IOPs for each test with SRPT thread enabled and then 
>>>>> not enabled. Test 4 seems to give the best results. Here's a brief 
>>>>> summary of that summary with just SRPT thread=0:
>>>>>
>>>>> Baseline: 356226.39
>>>>> Test 1:   371217.6533
>>>>> Test 2:   370553.78
>>>>> Test 3:   373295.2033
>>>>> Test 4:   399385.2233
>>>>> Test 5:   393204.5833
>>>> Linux CPU scheduler does really impressive job!
>>>>
>>>> Interesting, will something change with:
>>>>
>>>> 1. The latest SVN. It has some changes, which might make a difference.
>>> Sorry for the delay.
>>> This is with SVN rev 673. I don't hit the high I hit before, but at 
>>> a 1.8% difference (with test 4), it's statistically noise.
>>>
>>> Test 1: 390631.5133
>>> Test 2: 386125.4133
>>> Test 3: 356268.0267
>>> Test 4: 392237.7867
>>> Test 5: 390012.1467 
> I just ran again, this time with rev 680 and am a little concerned to 
> see the drop in performance. I verified that debug is not on. I'll try 
> to start another run on 680 to see if I get similar results.
>
> Test 1:368342.41
> Test 2:366787.2067
> Test 3:345334.68
> Test 4:372684.58
> Test 5:372184.8333
I re-compiled and re-ran the tests and numbers are a little better but 
performance still seems to have gone down from 673:
Test 1:373751.66
Test 2:371242.6067
Test 3:347988.1467
Test 4:378247.31
Test 5:375616.53