Re: [PATCH v2 0/4] mm: split the file's i_mmap tree for NUMA

[Huang Shijie]

On Thu, Jun 11, 2026 at 05:00:49PM +0100, Lorenzo Stoakes wrote:
> Hi Huang,
> 
> You seem to be replacing the file rmap altogether here, so you really ought
> to have sent this as an RFC so we could discuss it as a community first.
No problem.

> 
> Especially so as Pedro had publicly mentioned his plans to implement
> something similar here, so coordination would have been appreciated.
Yes. I am very happy to work with Pedro.

> 
> Anyway, as Pedro has pointed out, the code is overly complicated, it's far
> too configurable (not always a good thing), and the locking implementation
> is questionable.
I can make the code more simple. :)

> 
> You seem to be adding a whole bunch of open-coded complexity too, which is
> not something we want. Abstraction is key for the rmap.
> 
> You're also not adding any kdoc comments or really many comments at all,
> and you've not added any tests (though perhaps it's difficult given how
> core this is).
Got it.

> 
> So I would suggest that perhaps any respin should be sent as an RFC so we
> can engage in that conversation and ensure we're all on the same page?
> 
> Especially since Pedro plans to send an alternative, simpler, solution I
> believe.
> 
> It's also not helpful that you haven't examined the non-NUMA case :)
> perhaps your particular server behaves a certain way that this approach
> aids, but regresses other NUMA configurations?

emm. I ever hoped someone can help me to test this patch set on the non-NUMA
server.

It seems I should find some non-NUMA server before I send out the patch set. :)

> 
> We'd really need to be sure of this before accepting invasive changes like
> this.
Okay.

Thanks
Huang Shijie