linux-kernel - Re: [PATCH 3/5] mm: add static huge zero folio

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <iputzuntgitahlu3qu2sg5zbzido43ncykcefqawjpkbnvodtn@22gzzl5t77ct>
Date: Wed, 6 Aug 2025 14:28:52 +0200
From: "Pankaj Raghav (Samsung)" <kernel@...kajraghav.com>
To: David Hildenbrand <david@...hat.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@...cle.com>, 
	Suren Baghdasaryan <surenb@...gle.com>, Ryan Roberts <ryan.roberts@....com>, 
	Baolin Wang <baolin.wang@...ux.alibaba.com>, Borislav Petkov <bp@...en8.de>, Ingo Molnar <mingo@...hat.com>, 
	"H . Peter Anvin" <hpa@...or.com>, Vlastimil Babka <vbabka@...e.cz>, Zi Yan <ziy@...dia.com>, 
	Mike Rapoport <rppt@...nel.org>, Dave Hansen <dave.hansen@...ux.intel.com>, 
	Michal Hocko <mhocko@...e.com>, Andrew Morton <akpm@...ux-foundation.org>, 
	Thomas Gleixner <tglx@...utronix.de>, Nico Pache <npache@...hat.com>, Dev Jain <dev.jain@....com>, 
	"Liam R . Howlett" <Liam.Howlett@...cle.com>, Jens Axboe <axboe@...nel.dk>, linux-kernel@...r.kernel.org, 
	linux-mm@...ck.org, willy@...radead.org, x86@...nel.org, linux-block@...r.kernel.org, 
	Ritesh Harjani <ritesh.list@...il.com>, linux-fsdevel@...r.kernel.org, 
	"Darrick J . Wong" <djwong@...nel.org>, mcgrof@...nel.org, gost.dev@...sung.com, hch@....de, 
	Pankaj Raghav <p.raghav@...sung.com>
Subject: Re: [PATCH 3/5] mm: add static huge zero folio

On Wed, Aug 06, 2025 at 02:24:28PM +0200, David Hildenbrand wrote:
> On 06.08.25 14:18, Pankaj Raghav (Samsung) wrote:
> > > We could go one step further and special case in mm_get_huge_zero_folio() +
> > > mm_put_huge_zero_folio() on CONFIG_STATIC_HUGE_ZERO_FOLIO.
> > > 
> > 
> > Hmm, but we could have also failed to allocate even though the option
> > was enabled.
> 
> Then we return huge_zero_folio, which is NULL?
> 
> Or what are you concerned about?

But don't we want to keep the "dynamic" allocation part be present even
though we failed to allocate it statically in the shrinker_init?

Mainly so that the existing users of mm_get_huge_zero_folio() are not affected by
these changes.

> 
> -- 
> Cheers,
> 
> David / dhildenb
>