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From: Pasha Tatashin <pasha.tatashin@soleen.com>
Date: Wed, 5 Jun 2024 20:03:19 -0400
Message-ID: <CA+CK2bDD-S3xB4F8CHPLpUdfhTGf7=QJvoQL2XtdW3CYfiZ-GQ@mail.gmail.com>
Subject: Re: [PATCH v3] vmstat: Kernel stack usage histogram
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Shakeel Butt <shakeel.butt@linux.dev>, jpoimboe@kernel.org, kent.overstreet@linux.dev, 
	peterz@infradead.org, nphamcs@gmail.com, cerasuolodomenico@gmail.com, 
	surenb@google.com, lizhijian@fujitsu.com, willy@infradead.org, vbabka@suse.cz, 
	ziy@nvidia.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org
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On Fri, May 31, 2024 at 8:38=E2=80=AFPM Andrew Morton <akpm@linux-foundatio=
n.org> wrote:
>
> On Thu, 30 May 2024 20:14:17 -0400 Pasha Tatashin <pasha.tatashin@soleen.=
com> wrote:
>
> > > Couple of questions:
> > >
> > > 1. In future with your on-demand kstack allocation feature, will thes=
e
> > > metrics still be useful? (I think so but I want to know your take)
>
> I do think the changelog for this patch should reference the dynamic
> stack feature.  It strengthens the justification for adding this patch.

I will add a reference.

>
> > It depends on how on-demand allocation is implemented. On hardware
> > that supports faults on kernel stacks, we will have other metrics that
> > show the total number of pages allocated for stacks. On hardware where
> > faults are not supported, we will most likely have some optimization
> > where only some threads are extended, and for those, these metrics
> > will still be very useful.
>
> Also useful changelog info for this patch.
>
> Pasha, could you please prepare some additional text which I can paste
> in?  Thanks.

Yes, this makes sense, I will send a new version with the updated
commit log soon.

Thank you,
Pasha