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[82.69.66.36]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-43f2066d069sm221245635e9.17.2025.04.15.10.55.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 15 Apr 2025 10:56:00 -0700 (PDT) Date: Tue, 15 Apr 2025 18:55:58 +0100 From: David Laight To: Uros Bizjak Cc: linux-um@lists.infradead.org, x86@kernel.org, linux-kernel@vger.kernel.org, Richard Weinberger , Anton Ivanov , Johannes Berg , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" Subject: Re: [PATCH] um/asm: Replace "REP; NOP" with PAUSE mnemonic Message-ID: <20250415185558.112621df@pumpkin> In-Reply-To: <20250414145650.10776-1-ubizjak@gmail.com> References: <20250414145650.10776-1-ubizjak@gmail.com> X-Mailer: Claws Mail 4.1.1 (GTK 3.24.38; arm-unknown-linux-gnueabihf) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Mon, 14 Apr 2025 16:55:57 +0200 Uros Bizjak wrote: > Current minimum required version of binutils is 2.25, > which supports PAUSE instruction mnemonic. > > Replace "REP; NOP" with this proper mnemonic. > > No functional change intended. > > Signed-off-by: Uros Bizjak > Cc: Richard Weinberger > Cc: Anton Ivanov > Cc: Johannes Berg > Cc: Thomas Gleixner > Cc: Ingo Molnar > Cc: Borislav Petkov > Cc: Dave Hansen > Cc: "H. Peter Anvin" > --- > arch/x86/um/asm/processor.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/x86/um/asm/processor.h b/arch/x86/um/asm/processor.h > index 478710384b34..233a7a0d29c9 100644 > --- a/arch/x86/um/asm/processor.h > +++ b/arch/x86/um/asm/processor.h > @@ -24,7 +24,7 @@ > /* REP NOP (PAUSE) is a good thing to insert into busy-wait loops. */ > static __always_inline void rep_nop(void) > { > - __asm__ __volatile__("rep;nop": : :"memory"); > + __asm__ __volatile__("pause": : :"memory"); > } > That only makes sense if you also change the function name. David > static __always_inline void cpu_relax(void)