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charset=us-ascii Content-Disposition: inline In-Reply-To: <20260304153949.GP972761@nvidia.com> X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 7460C180011 X-Stat-Signature: t8wq55ee8mrbgfabiajzujxx3d537afs X-Rspam-User: X-HE-Tag: 1772645119-969454 X-HE-Meta: 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 Wz2r0h5q GfKGIx/+RY7QL4ZbHi5ttU+n1gEgWqzmTYuyZqAVSVdT4Ly4gugKP0hAd4nofS834b+2Nh/UJfAAe3fZaju66hpyDcgX4gBeCHem3cSZJQbB23kCID4pY/uBjkS1C3832kj9LAcYrkV28/Au5eOZmntvy9uQdbe49vXVKMHuFKY4PSC77KpzTolUXBA== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Wed, Mar 04, 2026 at 11:39:49AM -0400, Jason Gunthorpe wrote: > On Wed, Mar 04, 2026 at 03:01:51PM +0000, Catalin Marinas wrote: > > Good point. For the AF bit, the hardware is not allowed to cache it in > > the TLB, so we can't get an AF fault for an unrelated VA nearby. > > The way we have read the spec is there is no restriction on what PTE > the HW accesses when it encounters a CONT group. Trying to find some rule in the Arm ARM, it only says that hardware AF/DBM only happens to a single entry but it is not specific about which in a contiguous range. So yeah, it's better not to assume anything. If it helps software, we could tighten the architecture but I think the benefit is marginal. -- Catalin