Total latency (lat) of a workload test

[Eliezer Nebab <eliezer@integritech.solutions>]

Hello,

I have the following workload:

fio --randrepeat=1 --ioengine=libaio --direct=1 --sync=1 --name=test --filename=random_readwrite_test.fio --overwrite=1 --iodepth=64 --size=5GB --readwrite=randrw --rwmixread=50 --rwmixwrite=50 --bs=32k --runtime=60 --time_based --ramp_time=15

With the following result:

read : io=1949.4MB, bw=33249KB/s, iops=1038 , runt= 60035msec
    slat (usec): min=4 , max=30100 , avg=23.92, stdev=240.73
    clat (msec): min=1 , max=80 , avg=31.59, stdev= 8.94
     lat (msec): min=1 , max=80 , avg=31.61, stdev= 8.94

 write: io=1830.3MB, bw=31219KB/s, iops=975 , runt= 60035msec
    slat (usec): min=5 , max=30150 , avg=35.61, stdev=293.88
    clat (msec): min=1 , max=80 , avg=31.91, stdev= 8.82
     lat (msec): min=1 , max=80 , avg=31.95, stdev= 8.81

This is a 2000 iops iscsi. The read operation shows a 31.61 (msec) lat and the write operation at 31.95 (msec).  What is the correct way to interpret the total latency of this fio workload?  Do you add the read lat (31.61) plus write lat (31.95) to get the overall latency for this workload?

Thanks in advance for your input.

Eliezer