linux-kernel - Re: [PATCH v2 00/16] mm: remove is_swap_[pte, pmd]() + non-swap entries, introduce leaf entries

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Message-ID: <c9e3ad0e-02ef-077c-c12c-f72057eb7817@google.com>
Date: Mon, 10 Nov 2025 15:38:55 -0800 (PST)
From: Hugh Dickins <hughd@...gle.com>
To: Lorenzo Stoakes <lorenzo.stoakes@...cle.com>
cc: Chris Li <chrisl@...nel.org>, Andrew Morton <akpm@...ux-foundation.org>, 
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Subject: Re: [PATCH v2 00/16] mm: remove is_swap_[pte, pmd]() + non-swap
 entries, introduce leaf entries

On Mon, 10 Nov 2025, Lorenzo Stoakes wrote:
> On Mon, Nov 10, 2025 at 03:04:48AM -0800, Chris Li wrote:
> >
> > That is actually the reason to give the swap table change more
> > priority. Just saying.
> 
> I'm sorry but this is not a reasonable request. I am being as empathetic and
> kind as I can be here, but this series is proceeding without arbitrary delay.
> 
> I will do everything I can to accommodate any concerns or issues you may have
> here _within reason_ :)

But Lorenzo, have you even tested your series properly yet, with
swapping and folio migration and huge pages and tmpfs under load?
Please do.

I haven't had time to bisect yet, maybe there's nothing more needed
than a one-liner fix somewhere; but from my experience it is not yet
ready for inclusion in mm and next - it stops testing other folks' work.

I haven't tried today's v3, but from the cover letter of differences,
it didn't look like much of importance is fixed since v2: which
(after a profusion of "Bad swap offet entry 3ffffffffffff" messages,
not seen with v1, and probably not really serious) soon hits an Oops
or a BUG or something (as v1 did) - I don't have any logs or notes
to give yet, just forewarning before pursuing later in the day.

If you think v3 has fixed real crashes under load, please say so:
otherwise, I doubt it's worth Andrew hurrying to replace v2 by v3.

(Or have I got something bad in my build, and will have to apologize?
Or am I blaming your series - seems most likely - when it's actually
something else which came into mm in the last week?)

Hugh