[Darshan-users] [Ext] Re: Issues with Fio benchmark tool being profiled with Darshan

Neeraj Rajesh nrajesh at hawk.iit.edu
Wed Jul 15 13:43:11 CDT 2020


Hello Shane

I am using the release version on the Darshan website, (3.2.1). I shall
check out the master branch to see if I can generate accurate profiles and
can report back on it.

Thank you, Stay safe
Yours Sincerely
Neeraj Rajesh

On Wed, Jul 15, 2020 at 1:35 PM Snyder, Shane <ssnyder at mcs.anl.gov> wrote:

> Hi Neeraj,
>
> It looks like FIO might be using the 'openat()' call to open the files it
> is doing I/O to, which we only recently added support for. Assuming you
> aren't already, would it be possible for you to try the master branch of
> Darshan to see whether you can generate accurate profiles using that?
>
> Thanks,
> --Shane
> ------------------------------
> *From:* Darshan-users <darshan-users-bounces at lists.mcs.anl.gov> on behalf
> of Neeraj Rajesh <nrajesh at hawk.iit.edu>
> *Sent:* Tuesday, July 14, 2020 3:15 PM
> *To:* darshan-users at lists.mcs.anl.gov <darshan-users at lists.mcs.anl.gov>
> *Subject:* [Darshan-users] Issues with Fio benchmark tool being profiled
> with Darshan
>
> Hello
>
> I am trying to profile an Fio command, where I do roughly a gigabyte of
> reads or writes or mixed at a fixed block size.
> eg.
> ```
> fio --filename=./test --size=1024MB --direct=1 --rw=randrw --bs=4k
> --ioengine=sync --iodepth=256 --numjobs=1 --name=test-job --minimal
> --stats=0
> ```
> I have tested it with the following 'ioengines':
> - sync
> - psync
> - posixaio
> - pvsync
>
> I do get a darshan file, but all of the POSIX counters are 0, except for
> POSIX_F_META_TIME, POSIX_STATS, POSIX_FILE_ALIGNMENT and POSIX_MMAPS. I
> have ensured the operation is not simultaneously doing both POSIX and STDIO.
>
> As per my configuration it should not be getting 0s especially for the
> counters POSIX_SIZE_WRITE_1K_10K, POSIX_WRITES, POSIX_READS,
> POSIX_BYTES_WRITTEN, POSIX_BYTES_READ etc.
>
> Kindly advise what to do next.
>
> Thank you for your time, Stay safe
> Yours Sincerely
> Neeraj Rajesh
>
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