Re: [PATCH] backing_dev_info: introduce min_bw/max_bw limits

On Fri, 18 Jun 2021 at 10:31, Michael Stapelberg
[off-list ref] wrote:

Maybe, but I don’t have the expertise, motivation or time to
investigate this any further, let alone commit to get it done.
During our previous discussion I got the impression that nobody else
had any cycles for this either:
https://lore.kernel.org/linux-fsdevel/CANnVG6n=ySfe1gOr=0ituQidp56idGARDKHzP0hv=ERedeMrMA@mail.gmail.com/ (local)

Have you had a look at the China LSF report at
http://bardofschool.blogspot.com/2011/?
The author of the heuristic has spent significant effort and time
coming up with what we currently have in the kernel:

"""
Fengguang said he draw more than 10K performance graphs and read even
more in the past year.
"""

This implies that making changes to the heuristic will not be a quick fix.

Having a piece of kernel code sitting there that nobody is willing to
fix is certainly not a great situation to be in.

And introducing band aids is not going improve the above situation,
more likely it will prolong it even further.

Thanks,
Miklos