Re: [RFC PATCH] vm: align vma allocation and move the lock back into the struct

From: Suren Baghdasaryan
Date: Fri Aug 09 2024 - 12:57:00 EST


On Fri, Aug 9, 2024 at 3:09 PM Vlastimil Babka <vbabka@xxxxxxx> wrote:
>
> On 8/9/24 05:57, Suren Baghdasaryan wrote:
> > Maybe it has something to do with NUMA? The system I'm running has 2 NUMA nodes:
>
> I kinda doubt the NUMA aspect. Whether you allocate a vma that embeds a
> lock, or a vma and immediately the separate lock, it's unlikely they would
> end up on different nodes so from the NUMA perspective I don't see a
> difference. And if they ended up on separate nodes, it would more likely be
> worse for the case of separate locks, not better.

I have an UMA machine. Will try the test there as well. It won't
provide hard proof but at least some possible hints.