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

[Kent Overstreet <kent.overstreet@linux.dev>]

On Tue, Jul 08, 2025 at 08:22:09AM -0700, Suren Baghdasaryan wrote:
> 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.

Know anyone with expertise on the perf side?

I've been wondering (and haven't had time to check) if the CPU events
that perf consumes can report on the cacheline of the data miss, not
just the instruction we stalled on.