linux-kernel - Re: [PATCH] kho: add support for deferred struct page init

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Message-ID: <aVP6wBYoHJQsplIl@kernel.org>
Date: Tue, 30 Dec 2025 18:16:00 +0200
From: Mike Rapoport <rppt@...nel.org>
To: Pasha Tatashin <pasha.tatashin@...een.com>
Cc: Pratyush Yadav <pratyush@...nel.org>,
	Evangelos Petrongonas <epetron@...zon.de>,
	Alexander Graf <graf@...zon.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Jason Miu <jasonmiu@...gle.com>, linux-kernel@...r.kernel.org,
	kexec@...ts.infradead.org, linux-mm@...ck.org,
	nh-open-source@...zon.com
Subject: Re: [PATCH] kho: add support for deferred struct page init

On Tue, Dec 30, 2025 at 11:05:05AM -0500, Pasha Tatashin wrote:
> On Mon, Dec 29, 2025 at 4:03 PM Pratyush Yadav <pratyush@...nel.org> wrote:
> >
> > The magic is purely sanity checking. It is not used to decide anything
> > other than to make sure this is actually a KHO page. I don't intend to
> > change that. My point is, if we make sure the KHO pages are properly
> > initialized during MM init, then restoring can actually be a very cheap
> > operation, where you only do the sanity checking. You can even put the
> > magic check behind CONFIG_KEXEC_HANDOVER_DEBUG if you want, but I think
> > it is useful enough to keep in production systems too.
> 
> It is part of a critical hotpath during blackout, should really be
> behind CONFIG_KEXEC_HANDOVER_DEBUG

Do you have the numbers? ;-)

-- 
Sincerely yours,
Mike.