Re: [PATCH 0/4] move per-vma lock into vm_area_struct

Suren Baghdasaryan
2024-11-12T15:38:22Z

On Tue, Nov 12, 2024 at 1:39 AM Lorenzo Stoakes
<lorenzo.stoakes@oracle.com> wrote:
>
> On Mon, Nov 11, 2024 at 12:55:02PM -0800, Suren Baghdasaryan wrote:
> > Back when per-vma locks were introduces, vm_lock was moved out of
> > vm_area_struct in [1] because of the performance regression caused by
> > false cacheline sharing. Recent investigation [2] revealed that the
> > regressions is limited to a rather old Broadwell microarchitecture and
> > even there it can be mitigated by disabling adjacent cacheline
> > prefetching, see [3].
>
> Sorry to nag + add workload, but could you also add changes to the
> Documentation/mm/process_addrs.rst file to reflect this as part of the
> series? It'd be really cool to have the change as part of your series, so
> when it lands we update the documentation with it.
>
> This change fundamentally changes internals that are documented there so it
> makes sense to :)

Yep, I already prepared the documentation patch to be included in v2.
Sorry for missing it the first time around and thanks for the
reminder.

>
> Thanks!