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h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=j5AFHTTLzxiQjtqEvFZsht+b9/H6BjM/x3RwHls947twbgJc0VGaenS9OuNnNIJOT mEjbZ+iR1nCYefAMDmIk62GyEXF0p+Wocz/2eB8/qm06XSy16S6U1PRVbyU662kBAt jLhd7uZexScAhraTfyFOENpLJ/diDU8f6Yc/ZhcY= Date: Wed, 5 Aug 2026 15:48:14 +0100 From: Mark Rutland To: "Christoph Lameter (Ampere)" Cc: "David Hildenbrand (Arm)" , Yang Shi , "Lorenzo Stoakes (ARM)" , Linus Torvalds , Ryan Roberts , dennis@kernel.org, tj@kernel.org, urezki@gmail.com, catalin.marinas@arm.com, will@kernel.org, akpm@linux-foundation.org, hca@linux.ibm.com, gor@linux.ibm.com, agordeev@linux.ibm.com, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Jason Gunthorpe Subject: Re: [RFC v2 PATCH 0/16] Optimize this_cpu_*() ops for non-x86 (ARM64 for this series) Message-ID: References: <25d1e09b-53e4-7cd5-87db-b58437e4e690@gentwo.org> <4887267b-dc26-4c33-96ca-8dff054a0d1f@kernel.org> <69f4cd9c-bd6c-4e5d-b8d1-a7be8408a57a@os.amperecomputing.com> <94c7988a-3ecf-4b26-b0a8-011bdc76283b@kernel.org> <29edec61-8f11-b9b1-3df9-2a51815ee771@gentwo.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <29edec61-8f11-b9b1-3df9-2a51815ee771@gentwo.org> X-Rspam-User: X-Rspamd-Server: rspam03 X-Stat-Signature: d75ecim785wkg4z16nq4q3ztfxeojokm X-Rspamd-Queue-Id: 438761A000F X-HE-Tag: 1785941304-159821 X-HE-Meta: U2FsdGVkX1+ASbK+6fTnLqZfLGiPV+aWoVg4C4e0POzFnwgKVllfi/KEMqybB/vPjzYun5ORgnq40I3VbKJo41Aqa23zndvb5bAg+5646C/kdY9L0DsygjBOh2bW9rlVsLkSlcW7W5bCICS15fRTpyXrK6IIlRkamAgcGFdDRf1oEX4Kn+1K4ZoCHIQdD0ef/utVILIP+fII6lY7YyoE6G0GqQAsxpKePGmWRnw2DrprPiO0ixqoW4gw5wKqDIJ/m9wAL+a1iF06O+gEgjoCAtIK4t0VbXROAzHHvbPMufYp0eq/QB3fcM6lYVzDI7WRwlcTpVMFObzME+K5JKdFdncJR1TYKkL/yh/cQSvSKnx9J4qd2BUZK1ATZFCvqxuRW1fEoFTr2pm8dLryt1IyLRDA0Kno4CW3CI1taDHoWSz+ULdgdsURCN8vUzXEibnPj4AZa2p30e71PJhKmvYuC7oczjZHmr82PxF/kMTjfcB1OXDQ1zNTz4KJGPnbpMn7dtdd9/goeI1IVA2jkXrTY7J8chlbZ/9/58qA5pRQJlFO6TG8HIFoiLtwzMnlYv4RcZqssFhs6o3sVwypojT46ZpOdYpEqTbGuXtuWmYAKzTDjcCWNs5Hg/lwFUq12X6JvXElZj+oFodzgNPqIs/c7vLaAfIC/svYGxZeLrUFX18MmXqvW8/Nhnxo/ovls/UDzg+mDm7Rc0GPGXlRTmwkgMWV3nwj/+gKjHysVjwqI7hxnGDSgOiMdS8gTCTL6O5arebwquCGa5H1/Y4Zg12UrSgLuzDtQdu4cmGGu2wYhtqJ8JXg6vRXPVV8sx4pnp81u9WMUMuunWSxwidEucpeBMVDH+mDiSoGG1FzUGLvxdIfcDMBOutjgKdxWoYU4fZ7FEkK6Y6+KMIR1opzLMXlxuXxPBZXvQV3CvLZvyLibJUYX0pTUBwuj7bu0pJBrWAsVNpDw2VCLaecGHIcgum mkf/qThy e2x7qReVmVXh9dkyqiY1vDTIZMokDUvecPibZfY7zQVUtVMdIVRFqAlyZv/tgsZDtu9YwwgdpnDVBTil/6l3Erm4RCSTPgGEMZKxAzzOV3b0IdfSNpj3EN8wRmkuaWg68IZmho5CKiiRQ68FHo6DKPYnJUmFVXaj6NBi6ZeI2VUDv87WKSF2LJj6ZrhVrKMI4+pD3udflGJhCSv98onyhoJEcSji1L5Kjux8ZvlzOrJSDwXSoj0TI/iYRwH5snUWzE0+rLTXsXHzoyKN8G6VRut/JPg== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Tue, Aug 04, 2026 at 03:35:22PM -0700, Christoph Lameter (Ampere) wrote: > > > That's really all we are asking for. If there is a measurable performance > > difference, great. Share the results or point us at them if we missed them. > > Scanning over the patchset: It seems that you are using a special > instruction that is unfamiliar to me. Which processors support that? Which patch and which instruction are you referring to? There is no information to go on here. Asking on that specific patch would be helpful. Mark.