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Peter Anvin" , Joerg Roedel , suravee.suthikulpanit@amd.com, Robin Murphy , David Woodhouse , Baolu Lu , Herbert Xu , "David S . Miller" , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , Vlastimil Babka , Roman Gushchin , Hyeonggon Yoo <42.hyeyoo@gmail.com>, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-s390@vger.kernel.org, iommu@lists.linux.dev, Linux-Arch , linux-crypto@vger.kernel.org, mpe@ellerman.id.au Subject: Re: [PATCH v3 00/11] Introduce cmpxchg128() -- aka. the demise of cmpxchg_double() Message-ID: <20230524093947.GQ83892@hirez.programming.kicks-ass.net> References: <20230515075659.118447996@infradead.org> <4975b92f-92f6-4d50-8386-9add12ddfd61@app.fastmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4975b92f-92f6-4d50-8386-9add12ddfd61@app.fastmail.com> X-Stat-Signature: oso5s4n6hki6hj3muqhc36wyjikjwqz4 X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: A4D98A0012 X-Rspam-User: X-HE-Tag: 1684921208-775819 X-HE-Meta: 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 3RNo4RO6 73qQXk2iUS5iW3f0LwXRBgBsCmRdQneMlZ3jG077kXy93AIsMnCFk1awBa73g5lrNfXby/Y/sz0FM7HHDQ5h85zSlwdrFJ89VYAeEnpe/Mm7FMoykSZyufPPC+UBPPttCcVa90U/TwQ1MFm65ZWh7PR21AKFPAX/d2h8tQAO56LCOIqBkrL+rE9CpBc9QMNgQyulu62du7jnt2zMjeBb9p1edC9/qIfJWKGIjh+oYQs9bydLhRxUtHTq3CQk3GD71KN3mpHOEJ5n8tX6llRvdbX5o2A== 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: On Mon, May 15, 2023 at 11:42:23AM +0200, Arnd Bergmann wrote: > The need for runtime feature checking in the callers on x86-64 is still > a bit awkward, but this is no worse than before. I understand that > turning this into a compile-time choice would require first settling > a larger debate about raising the default target for distros beyond > the current CONFIG_GENERIC_CPU. Looks like Power is going to be in the same boat, they can do cmpxchg128, but only for Power8+.