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[82.69.66.36]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-49895f4e6ffsm15149402f8f.16.2026.11.12.04.09.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 12 Nov 2026 04:09:34 -0800 (PST) Date: Thu, 12 Nov 2026 12:09:28 +0000 From: David Laight To: Yunhui Cui Cc: pjw@kernel.org, palmer@dabbelt.com, aou@eecs.berkeley.edu, alex@ghiti.fr, dennis@kernel.org, tj@kernel.org, cl@gentwo.org, oleg@redhat.com, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, eddyz87@gmail.com, memxor@gmail.com, martin.lau@linux.dev, song@kernel.org, yonghong.song@linux.dev, jolsa@kernel.org, emil@etsalapatis.com, ihor.solodrai@linux.dev, bjorn@kernel.org, pulehui@huawei.com, puranjay@kernel.org, broonie@kernel.org, dave@stgolabs.net, jszhang@kernel.org, tglx@kernel.org, conor.dooley@microchip.com, thuth@redhat.com, ajones@ventanamicro.com, ben.dooks@codethink.co.uk, rkrcmar@ventanamicro.com, samuel.holland@sifive.com, zong.li@sifive.com, debug@rivosinc.com, seanwascoding@gmail.com, andybnac@gmail.com, menglong8.dong@gmail.com, cyrilbur@tenstorrent.com, wangruikang@iscas.ac.cn, atishp@rivosinc.com, apatel@ventanamicro.com, arnd@arndb.de, nathan@kernel.org, nick.desaulniers+lkml@gmail.com, morbo@google.com, justinstitt@google.com, qingfang.deng@siflower.com.cn, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, bpf@vger.kernel.org, linux-arch@vger.kernel.org, llvm@lists.linux.dev Subject: Re: [PATCH v10 5/9] riscv: implement preemptible this_cpu add_return operations Message-ID: <20261112120928.24145d44@pumpkin> In-Reply-To: <20261112104149.38589-6-cuiyunhui@bytedance.com> References: <20261112104149.38589-1-cuiyunhui@bytedance.com> <20261112104149.38589-6-cuiyunhui@bytedance.com> X-Mailer: Claws Mail 4.1.1 (GTK 3.24.38; arm-unknown-linux-gnueabihf) X-Mailing-List: bpf@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Thu, 12 Nov 2026 18:41:45 +0800 Yunhui Cui wrote: > Apply the recoverable per-CPU address handling to add-return operations. > > Native-width AMOs return the old value, so derive the new value required > by the percpu API from the operand. Use Zabha for subword operations when > available, or a masked LR/SC sequence that returns the updated field. I can't help feeling that some of this code is the same as that for normal atomic accesses. Can they me merged? David