Multiple jobs and fill_device

[Oleg Sivokon <oleg.sivokon@replix.io>]

Hello list,

I'm wondering how the configuration below is interpreted:

    [global]
    ioengine=libaio
    direct=1
    loops=1
    numjobs=8
    
    [write-prep]
    rw=write
    filename=/dev/sdb
    iodepth=16
    bs=16k
    fill_device=1
    stonewall=1

Will every one of the 8 jobs try to fill the device completely or will
they split the task of filling the device between themselves, where each
will do only 1/8 of filling the device?  My reading of documentation
seems to suggest the device will be filled 8 times, with jobs, possibly,
stepping on each other's toes (i.e. contesting the same block), but I'm
not sure.

Best.

Oleg