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Peter Anvin" , Catalin Marinas , james.morse@arm.com, linux-cxl@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-acpi@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, gregkh@linuxfoundation.org, Will Deacon , Davidlohr Bueso , Yicong Yang , Yushan Wang , Lorenzo Pieralisi , Mark Rutland , Dave Hansen , Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, Andy Lutomirski Subject: Re: [PATCH v2 0/8] Cache coherency management subsystem Message-ID: <20250710105913.GB542000@noisy.programming.kicks-ass.net> References: <20250624154805.66985-1-Jonathan.Cameron@huawei.com> <20250625085204.GC1613200@noisy.programming.kicks-ass.net> <20250625093152.GZ1613376@noisy.programming.kicks-ass.net> <20250625180343.000020de@huawei.com> <20250626105530.000010be@huawei.com> <686f506020726_1d3d10069@dwillia2-xfh.jf.intel.com.notmuch> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <686f506020726_1d3d10069@dwillia2-xfh.jf.intel.com.notmuch> X-Rspam-User: X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: 1DE531C0014 X-Stat-Signature: mskiis8rdj64jpbajg6fbpu48k5bdrdp X-HE-Tag: 1752145178-517003 X-HE-Meta: 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 4Elg+rKL UAEWLkeSeoxgLkxHovy8ZKRjIwMRjUZ+V/5CQA+TBIfa/Xw1rKVYLLfyfWF7oDBrxrgFhWvxRsTuWj9k/gkK0nClc4K4G3gC60ubFAwKlQd2jRQ/AQt+s5PmaQHYjoquglnEhZSixiFc5bZCvVskG/UNIVRqhKP303bok 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 Wed, Jul 09, 2025 at 10:32:16PM -0700, dan.j.williams@intel.com wrote: > Theoretically there could be a threshold at which a CLFLUSHOPT loop is a > better option, but I would rather it be the case* that software CXL > cache management is stop-gap for early generation CXL platforms. So isn't the problem that CLFLUSH and friends take a linear address rather than a physical address? I suppose we can use our 1:1 mapping in this case, is all of CXL in the 1:1 map?