On Thu, 19 Sept 2024 at 16:15, Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote:
>
> Agreed. From the description this would seem like a good fit for
> q_usage_counter in the block layer, which currently makes creative use
> of percpu counters.
Yes, if this actually could simplify code that currently used percpu
counters, that might be lovely.
The percpu counters often perform very well, but then have huge pain
in either managing the percpu allocation, or in trying to synchronize
across CPU's.
I'd be a lot more interested in "we can fix complex code" than in "we
have crappy code in bad subsystems where we can hide the performance
impact of the subsystem not having been done right".
Linus
