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Tue, 28 May 2024 13:49:39 -0700 (PDT) Date: Tue, 28 May 2024 13:49:36 -0700 From: Dennis Zhou To: "Christoph Lameter (Ampere)" , Alexey Dobriyan Cc: tj@kernel.org, linux-mm@kvack.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com Subject: Re: [PATCH] x86/percpu: fix cast in __pcpu_cast_* macros Message-ID: References: <81264b6c-fd23-2ee5-52cd-249047e317a7@linux.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <81264b6c-fd23-2ee5-52cd-249047e317a7@linux.com> X-Rspamd-Queue-Id: 8B45E160010 X-Stat-Signature: bakm5yzz5qo5i9irdub81i1791jm4tqp X-Rspam-User: X-Rspamd-Server: rspam08 X-HE-Tag: 1716929380-285253 X-HE-Meta: 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 gHISeeHI StpqfQ8KERQn+XNNSXDic3+/LBfpxbL2wo4u3aRzIqOL7Ujz+9iOYZEoacgEQGGdXK2FT0TQog6TRl8e0HnW4wkaZdMX3Pjml4tyb4ES/ABAlO2KeaAsY9ClFhNHeUGC4TXiO6QSoHCOY7nv9Aggt/jfUI2uKcNgfPapY54kNlNSZ9RR9SMIsfRdz9LEWF//iN6DRnTDnQcFGnQH9o9MzuGs4UYbTptCg6zl9eP3WDX/zzy/vE+zq2kEN2L3/KcJRRVkUz5HIKwTO93ONKOxQUL7xhTJ9lT4D4wKyUyNqFrLME2RDYvkWssIyCERHEUixmph/08IK5HBVDCIO3og9XAxByhhssnQW4jboyCfnWHh5GRgj3sXF0TGtPbgv+HRMcsTYtEPBR8Cr08uelDRUJk53Nf+9o0aTy0qxeJMCQjqKkkm0Y6ntumLcD1En2/zoo+8hxYwN19/j05WMXx87TzDq3WDX4tLJrYT/ X-Bogosity: Ham, tests=bogofilter, spamicity=0.000001, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Hi Alexey, On Tue, May 28, 2024 at 01:43:27PM -0700, Christoph Lameter (Ampere) wrote: > On Mon, 27 May 2024, Alexey Dobriyan wrote: > > > this_cpu_add(*p, x = 1); > > A side effect in a this_cpu_op? Shudder.... > At the end of the day this is Thomas' code, but I can't imagine a single use case where this is a good idea. Especially with how much fun percpu macros end up being. Thanks, Dennis