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Received: from 77-249-17-252.cable.dynamic.v4.ziggo.nl ([77.249.17.252] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.98.2 #2 (Red Hat Linux)) id 1vuo5N-00000006hUZ-3Wje; Tue, 24 Feb 2026 08:48:06 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 48CEF30095A; Tue, 24 Feb 2026 09:48:04 +0100 (CET) Date: Tue, 24 Feb 2026 09:48:04 +0100 From: Peter Zijlstra To: Anshuman Khandual Cc: linux-arm-kernel@lists.infradead.org, Catalin Marinas , Will Deacon , Ryan Roberts , Mark Rutland , Lorenzo Stoakes , Andrew Morton , David Hildenbrand , Mike Rapoport , Linu Cherian , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , linux-perf-users@vger.kernel.org Subject: Re: [RFC V1 04/16] perf/events: Replace READ_ONCE() with standard pgtable accessors Message-ID: <20260224084804.GU1282955@noisy.programming.kicks-ass.net> References: <20260224051153.3150613-1-anshuman.khandual@arm.com> <20260224051153.3150613-5-anshuman.khandual@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260224051153.3150613-5-anshuman.khandual@arm.com> X-Rspam-User: X-Stat-Signature: kuyfm7jwntgm6frz68embbsmsihyjcqi X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: A43D620007 X-HE-Tag: 1771922889-898187 X-HE-Meta: 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 oJu3o+RD GkcCkXi4Y7kbyhN4Lk60Yq92gN2PnNpgQ9HPL65af0gBPiF80Og3hvnOn3Gb+sR6Ix4FwkcHTJ0dv4DO+a17FbRzjBBOU8jnU6KTiGCGGrm6UWKaI/yG0es0G2oehZDHVZQ9UuAorDbkMZLLJDxTe/YKLg5csDVQQ01lwqnzgK4IxbS6VK+j7W4Skr9vNjvC9d9G0I3HnDEFxfPH0Rh0pswEsoz+GnFMQjkRs2VDNmQVVJULhP1Lob2NVu03WqQamahAXEzFJZS2o634= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Tue, Feb 24, 2026 at 10:41:41AM +0530, Anshuman Khandual wrote: > Replace READ_ONCE() with standard page table accessors i.e pxdp_get() which > anyways default into READ_ONCE() in cases where platform do not override. This is a bit silly, no? All of them should always be READ_ONCE(), with the exception of pte_get() on PAE like scenarios.