Re: [PATCH] fuse: disable default bdi strictlimiting

Re: [PATCH] fuse: disable default bdi strictlimiting

[Miklos Szeredi]

On Mon, 27 Oct 2025 at 23:39, Joanne Koong <joannelkoong@gmail.com> wrote:
> Miklos, could you share your thoughts on this? Are you in favor of
> disabling default strictlimiting? Or do you prefer to have it kept
> enabled by default, with some mount option or sysctl added for
> privileged servers to be able to disable strictlimiting + enable large
> folios if they use the writeback cache?

So what I think we should do is implement some sort of slow writer
test, and see what happens with and without strictlimit.

Tried to ask claude to do this for me, but not getting very far.

So if I take this maintainership role seriously and not let myself
drown in the details, then the logical thing to do is to delegate ;)
Which is hard (for me at least) but I'll give it a try...

Could you please check how things change if there's limited writeback
rate and we disable strictlimit?  And what happens if there are
several such instances running in parallel?

Thanks,
Miklos

Re: Re: [PATCH] fuse: disable default bdi strictlimiting

[Horst Birthelmer]

On Fri, May 08, 2026 at 11:42:10AM +0200, Miklos Szeredi wrote:
> On Mon, 27 Oct 2025 at 23:39, Joanne Koong <joannelkoong@gmail.com> wrote:
> > Miklos, could you share your thoughts on this? Are you in favor of
> > disabling default strictlimiting? Or do you prefer to have it kept
> > enabled by default, with some mount option or sysctl added for
> > privileged servers to be able to disable strictlimiting + enable large
> > folios if they use the writeback cache?
> 
> So what I think we should do is implement some sort of slow writer
> test, and see what happens with and without strictlimit.
> 
> Tried to ask claude to do this for me, but not getting very far.
> 
> So if I take this maintainership role seriously and not let myself
> drown in the details, then the logical thing to do is to delegate ;)
> Which is hard (for me at least) but I'll give it a try...
> 
> Could you please check how things change if there's limited writeback
> rate and we disable strictlimit?  And what happens if there are
> several such instances running in parallel?

We have run all kinds of workloads and tests (xfstest, too) with 
writeback enabled and strictlimiting off.

I have not noticed any problems, but we have not done any systematic
tests regarding this. We were always testing something else.
(usually performance impacts)

Thanks,
Horst