From: Heiko Carstens <hca@linux.ibm.com> To: Yang Shi <yang@os.amperecomputing.com> Cc: "David Hildenbrand (Arm)" <david@kernel.org>, cl@gentwo.org, dennis@kernel.org, tj@kernel.org, urezki@gmail.com, catalin.marinas@arm.com, will@kernel.org, ryan.roberts@arm.com, akpm@linux-foundation.org, gor@linux.ibm.com, agordeev@linux.ibm.com, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [RFC v1 PATCH 0/11] Optimize this_cpu_*() ops for non-x86 (ARM64 for this series) Date: Fri, 15 May 2026 18:28:04 +0200 [thread overview] Message-ID: <20260515162804.10935A18-hca@linux.ibm.com> (raw) In-Reply-To: <583d5984-fc21-4204-9845-8ceabacf823f@os.amperecomputing.com> On Wed, May 13, 2026 at 05:00:19PM -0700, Yang Shi wrote: > On 5/12/26 2:02 AM, David Hildenbrand (Arm) wrote: > > There was quite some feedback during the LSF/MM session, what's the current plan? ... > I'm not sure whether S390 folks will implement this on S390 or not, anyway > they are cc'ed. I'm not sure yet, however after I had a look at the architecture documentation a couple of weeks ago, I think it shouldn't be too hard to get this working on s390 as well. I was a bit concerned about TLB flushing, if changes to the kernel mapping happen with per-cpu page tables, but as of now I believe this shouldn't cause any harm (famous last words...).