A question about fio flows

Hi all,

I am working on some experiments where I need to have 12 jobs. Each
job is reading from a different file (job1 -> file1, job2 -> file2,
etc).

Now, some files should receieve more I/O than others. To implement this
bias between files, I opted for flows. Basically, I start from 100 and I
assign a percentage to each file. For example, a snippet of my fio job
file below:

[private-0]
flow=37
filename=/srv/dax/private/private-0
[private-1]
flow=23
filename=/srv/dax/private/private-1
[private-2]
flow=10
filename=/srv/dax/private/private-2
[private-3]
flow=9
filename=/srv/dax/private/private-3
[private-4]
flow=7
filename=/srv/dax/private/private-4
[private-5]
flow=3
filename=/srv/dax/private/private-5
[private-6]
flow=3
filename=/srv/dax/private/private-6

I am not sure if this is properly achieving what I want to achieve.

I have a doubt that having too many files and many flows will reduce
scheduling precision or introduce scheduling overhead. I don't know how
this feature is implemented internally, thus my question.

Can you please briefly explain how the feature works. And Do you think
this is a sane approach? If not, what better alternative can I use?

-- 
Best,
Karim
Edinburgh University