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From: Lorenzo Stoakes <ljs@kernel.org>
To: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: "Oscar Salvador (SUSE)" <osalvador@kernel.org>,
	 Andrew Morton <akpm@linux-foundation.org>,
	David Hildenbrand <david@redhat.com>,
	 Anshuman Khandual <anshuman.khandual@arm.com>,
	Oscar Salvador <osalvador@suse.de>,
	 Wei Yang <richard.weiyang@gmail.com>,
	linux-s390@vger.kernel.org, linux-mm@kvack.org,
	 linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3] mm/page_vma_mapped_walk: Use ptep_get_lockless() for lockless access
Date: Mon, 1 Jun 2026 10:36:33 +0100	[thread overview]
Message-ID: <ah1SmDJFAcGdBVvU@lucifer> (raw)
In-Reply-To: <07baafe4-7d1c-42b0-9103-3e5666770061-agordeev@linux.ibm.com>

On Thu, May 28, 2026 at 04:30:36PM +0200, Alexander Gordeev wrote:
> On Thu, May 28, 2026 at 04:14:03PM +0200, Oscar Salvador (SUSE) wrote:
> > On Thu, May 28, 2026 at 12:24:35PM +0100, Lorenzo Stoakes wrote:
> > > On Thu, May 28, 2026 at 09:55:07AM +0200, Alexander Gordeev wrote:
> > > > Switch from ptep_get() to ptep_get_lockless() accessor for
> > > > PTE reads when no lock is taken.
> > >
> > > This is an insufficient commit message that's just saying what you're doing,
> > > which isn't very useful.
> > >
> > > Please explain why you're doing this and what the benefit is please.
> >
> > Maybe something like
> >
> > "When not holding the lock, there is a chance that the pte gets modified
> >  under our feet, so we need to use the lockless API to make sure that
> >  the entries remain consistent during the read."
>
> I would gladly use this, if it makes sense for everyone.
>
> @Lorenzo?

Sounds good to me! Thanks

>
> > Only arm64 makes use of it though, due to the contpte stuff and being
> > unable to do it atomically.
>
> Thanks!
>
> > --
> > Oscar Salvador
> > SUSE Labs

Cheers, Lorenzo


  reply	other threads:[~2026-06-01  9:36 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-05-28  7:55 [PATCH v3] mm/page_vma_mapped_walk: Use ptep_get_lockless() for lockless access Alexander Gordeev
2026-05-28  9:09 ` Wei Yang
2026-05-28 11:24 ` Lorenzo Stoakes
2026-05-28 14:14   ` Oscar Salvador (SUSE)
2026-05-28 14:30     ` Alexander Gordeev
2026-06-01  9:36       ` Lorenzo Stoakes [this message]
2026-05-29 17:34 ` Oscar Salvador (SUSE)
2026-06-01 12:10 ` David Hildenbrand (Arm)
2026-06-01 12:15 ` Lorenzo Stoakes

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