log_offset seems to be getting ignores

[garengllc]

The log_offset flag seems to be getting ignored as well as defaulting to on.

My command is:

sudo LD_PRELOAD=/home/jason/epiq/speed/spdk/examples/nvme/fio_plugin/fio_plugin /home/jason/epiq/speed/fio/fio --name=write --ioengine=spdk --iodepth=4 --rw=write --bs=4k --direct=1 --runtime=3s --numjobs=8 --group_reporting --thread=1 --filename='trtype=PCIe traddr=0000.3b.00.0 ns=1' --log_offset=0 --write_bw_log=fio-test --write_iops_log=fio-test --write_lat_log=fio-test --per_job_logs=0

I am on fio-3.18. Leaving "--log_offset=0" off the command does the same thing.

And example snippet of fio-test_bw.log looks like:

0, 82732, 1, 4096, 0
0, 6509, 1, 4096, 0
0, 6486, 1, 4096, 0
0, 6477, 1, 4096, 0
0, 134215, 1, 4096, 0
0, 149707, 1, 4096, 0
0, 92350, 1, 4096, 0
0, 91044, 1, 4096, 0
0, 135777, 1, 4096, 0
0, 136597, 1, 4096, 0
0, 107763, 1, 4096, 0
0, 106761, 1, 4096, 0
0, 132065, 1, 4096, 0
0, 132299, 1, 4096, 0
0, 82889, 1, 4096, 0
0, 83694, 1, 4096, 0

Which of course means that tools/plot/fio2gnuplot doesn't work:

1 files Selected with pattern '*_bw.log'
 |-> fio-test_bw.log

Traceback (most recent call last):
  File "tools/plot/fio2gnuplot", line 532, in <module>
    sys.exit(main(sys.argv))
  File "tools/plot/fio2gnuplot", line 510, in main
    blk_size=compute_temp_file(fio_data_file,disk_perf,gnuplot_output_dir,min_time,max_time)
  File "tools/plot/fio2gnuplot", line 201, in compute_temp_file
    time, perf, x, block_size = line[1]
ValueError: too many values to unpack

[pzoxiuv]

I think that last column isn't the offset but rather the priority bit which was introduced in b2a432b. It doesn't look like that commit lets you disable it.

You can easily patch fio2gnuplot to handle the extra column though: pzoxiuv@94b940a

[sitsofe]

@pzoxiuv If your patch is generic would you like to submit it as a pull request?

[sitsofe]

@trinof Could you submit a documentation update to

fio/HOWTO

Line 4161 in 14060eb

Log File Formats

and https://github.com/axboe/fio/blob/master/fio.1#L3861 in the light of the high priority bit logging change?

[trinof]

Sure, I'll send a small patch out

[sitsofe]

Ping @pzoxiuv - would you like to submit a pull request?