Sitsofe Wheeler <sitsofe@xxxxxxxxx> writes: > Hi, > > On Fri, 22 Feb 2019 at 16:19, Jing Booth <Jing.Booth@xxxxxxx> wrote: >> >> Hi all, >> >> In the test script shown below, it has [global] section and >> [nvme0n1] section. The test script is used to test a storage >> device. What queue depth does the storage device receive? Thanks >> >> fio --name=global --ba=16K --bs=16K --buffered=0 --ioengine=libaio >> --nice=-10 --rw=randrw --size=100% --status-interval=1 --ramp_time=2 >> --runtime=5 --time_based --rwmixread=25 --group_reporting >> --numjobs=4 --iodepth=16 --norandommap >> --random_generator=tausworthe64 --randrepeat=0 >> --percentile_list=99:99.9:99.99:99.999:99.9999:99.99999:99.999999:99.9999999 >> --name=nvme0n1 --filename=/dev/nvme0n1 --iodepth=64 > > Something like 4 if you count all jobs together (because numjobs is 4) > but you can check for yourself by looking at the submit line in the IO > depths output that fio produces. > > Did you see the warnings with the libaio engine in the > manual/documentation > (https://fio.readthedocs.io/en/latest/fio_doc.html#i-o-engine ) or the > warning in the iodepth option section > (https://fio.readthedocs.io/en/latest/fio_doc.html#cmdoption-arg-iodepth > )? He specified buffered=0. The end result will by 64 * 4 = 256. Of course, at the device things may differ due to splitting and/or merging of I/O in the kernel. Cheers, Jeff
