Did you try current -git yet? I think it should work for both scenarios.
It's a silly bug, would be great to have confirmation that it's fixed.
Then I'll spin a new release.
On 11/20/2015 05:21 PM, Jens Axboe wrote:
And finally, there's a potential fix, if you run commit
99afcdb53dc3 or later. So please do try that as well, and
see if that behaves any better for you.
On 11/20/2015 05:03 PM, Jens Axboe wrote:
Hi,
OK, I see. Can you pull the latest -git, and then run fio
--cpuclock-test on one of the boxes where you see the issue? It should
have commit 5896d827e1e2 or later.
On Fri, Nov 20, 2015 at 3:20 PM, Akash Verma <akashv@xxxxxxxxxx
<mailto:akashv@xxxxxxxxxx>> wrote:
Hi Jens,
The issue is not seen with non-cpu clock sources, or when using a
single process (with individual threads, the only config I tried). We
only see the issue when using multiple processes and the cpu clock
source.
On Fri, Nov 20, 2015 at 11:50 AM, Jens Axboe <axboe@xxxxxxxxx
<mailto:axboe@xxxxxxxxx>> wrote:
> On 11/20/2015 12:37 PM, Caio Villela wrote:
>>
>> Hello Allen and Jens,
>>
>> Sorry for the long output, this is just in case you want the
details.
>> Here is a simple explanation for the problem. I want to run a 15
minute
>> random write, using 1 Meg requests, and measure throughput and
latency.
>> What seems to be the problem is that if the test system has a
large
>> number of drives - the system that I am testing here has 28
drives -
>> then the time accounting seems to go bad for some of the
processes.
>> What you see below is that during the 15 minutes from start, all
disks
>> are getting hit the same, as they should. Then, after 15
minutes, there
>> are 15 drives that are still running.... after 5 minutes over the
>> specified 15 minutes, there is still one drive running. Then
looking at
>> the amount of IOs sent to each drive, the ones that ran on that
excess
>> time have much more IOs. FIO still reports that all drives ran
for 15
>> minutes, although some ran for more than 20 minutes.
>>
>> We will attempt to run a single process instead of 28 instances
of FIO
>> to see if this goes away.
>
>
> Could you also check if adding clocksource=gettimeofday makes any
> difference? This sounds very odd.
>
> Assuming this was run with fio -git?
>
>
> --
> Jens Axboe
>
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