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[209.85.218.46]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-a93c299ac9asm151315666b.208.2024.09.27.09.44.28 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 27 Sep 2024 09:44:28 -0700 (PDT) Received: by mail-ej1-f46.google.com with SMTP id a640c23a62f3a-a8d0d82e76aso340729966b.3 for ; Fri, 27 Sep 2024 09:44:28 -0700 (PDT) X-Forwarded-Encrypted: i=1; AJvYcCW+/ArYH2m4iVtwUE+uKb+skjyzEju/neRNa6Q1c4tbdGlIxXaPYfkDN64KkIedhL1EyAeIHG36ww==@kvack.org X-Received: by 2002:a17:907:748:b0:a7a:b73f:7584 with SMTP id a640c23a62f3a-a93c492a391mr352824766b.34.1727455468157; Fri, 27 Sep 2024 09:44:28 -0700 (PDT) MIME-Version: 1.0 References: <4167e6f5-4ff9-4aaa-915e-c1e692ac785a@efficios.com> <48992c9f-6c61-4716-977c-66e946adb399@efficios.com> <2b2aea37-06fe-40cb-8458-9408406ebda6@efficios.com> <55633835-242c-4d7f-875b-24b16f17939c@huaweicloud.com> <54487a36-f74c-46c3-aed7-fc86eaaa9ca2@huaweicloud.com> <0b262fe5-2fc5-478d-bf66-f208723238d5@efficios.com> In-Reply-To: From: Linus Torvalds Date: Fri, 27 Sep 2024 09:44:11 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [RFC PATCH 1/4] hazptr: Add initial implementation of hazard pointers To: Boqun Feng Cc: Mathieu Desnoyers , Jonas Oberhauser , linux-kernel@vger.kernel.org, rcu@vger.kernel.org, linux-mm@kvack.org, lkmm@lists.linux.dev, "Paul E. McKenney" , Frederic Weisbecker , Neeraj Upadhyay , Joel Fernandes , Josh Triplett , "Uladzislau Rezki (Sony)" , rostedt , Lai Jiangshan , Zqiang , Peter Zijlstra , Ingo Molnar , Will Deacon , Waiman Long , Mark Rutland , Thomas Gleixner , Kent Overstreet , Vlastimil Babka , maged.michael@gmail.com, Neeraj Upadhyay Content-Type: text/plain; charset="UTF-8" X-Rspam-User: X-Rspamd-Queue-Id: 934AFA0004 X-Rspamd-Server: rspam01 X-Stat-Signature: hmmbjiamgcc9o5ht97n5b9okkpambbqu X-HE-Tag: 1727455470-854772 X-HE-Meta: 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 cYv+0Xgn 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 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 Thu, 26 Sept 2024 at 18:38, Boqun Feng wrote: > > Note that ADDRESS_EQ() only hide first parameter, so this should be ADDRESS_EQ(b, a). Yeah, please stop making things unnecessarily complicated. Just use a barrier(). Please. Stop these stupid games until you can show why it matters. And by "why it matters" I mean "major difference in code generation", not some "it uses one more register and has to spill" kind of small detail. At this point, I'm not even convinced the whole hazard pointer approach makes sense. And you're not helping by making it more complicated than it needs to be. Linus