Re: [PATCH mm-next] alloc_tag: add total bytes allocation information

[Suren Baghdasaryan <surenb@google.com>]

On Tue, Jul 8, 2025 at 8:13 AM Kent Overstreet
<kent.overstreet@linux.dev> wrote:
>
> On Tue, Jul 08, 2025 at 07:38:40AM -0700, Suren Baghdasaryan wrote:
> > Why not just use what we already have?
> >
> > awk '{sum += $1} END {print sum}' /proc/allocinfo
>
> For this sure, but there've been several feature requests - the per numa
> node stats is the big one that I think would justify a more extensible
> ioctl interface. We don't want to change the existing /proc/allocinfo
> for that.

I see. About the NUMA awareness patch proposed at
https://lore.kernel.org/all/20250610233053.973796-1-cachen@purestorage.com/,
I'm checking with other teams at Google whether this would be useful.
For Android which always uses a single NUMA node that's obviously not
very interesting but for others it might be. Will follow up on that
thread once I have some more info.

>
> The big thing on my mind is starting to come up with an API for getting
> this into other userspace tooling; if we could eventually figure how to
> to teach perf to do the address -> owner lookup for cache misses that
> would be huge.