From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C066422652E for ; Fri, 21 Mar 2025 21:22:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742592160; cv=none; b=FaHQgHCmJ6sZwd4ljwNMz4r/nfCIQ9PG/XdknjE86U+JNdpTF7T+gQaLXi2vI5MDL6/snBSgYcOOZ9UZZ9ku6+TV/w5rWaja/RFi4p+T9raMqdkmiR2oHUu2tPYYMqo2VStxv5ER5X3NR8NM2p3zIh8Yyn6j1AGdsK9szbQPLsA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742592160; c=relaxed/simple; bh=MLoEPj1DotaiblARy+HIv8f7Oy71CnrchBnjpKyGesU=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=XtMAJeh9l1uyQC8Vo5m2yhTma7dsC5mIMdTffikSf5fnKl6GKOOsut3GZo0Difh1wJbm1myR1M5k+/mdXGnW6OKJ7g9w5LTtw2a9eWsiXTW4pHR5ih2ubS+GrWVCv4Y43wD83RU8pqqKyg9FqHCTZCVeJ1HfK06DKaSWGTJ8egk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=urekzMMt; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=EZS5gE+V; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="urekzMMt"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="EZS5gE+V" From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1742592157; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=+oNseWKuGBEgshNs5P0talv9xg+inN17z1K2AF90QsY=; b=urekzMMtfA3kTy822lbKa4nufWzR1OXLr8MKXehncBoDdm+XaFkjEu7bTZMYsxv8ltVwoi lvGqR9Z+4hyzbhRh4AC896uxdlwHvHw0veohERNmwzCmdAQ04k4q/CHT/60zHV4CdzuzTA n6YkpC/n1jRVZjiX3ycpakTyHVyDhKkoHtGemUXzU9umIyUgY056GYou5iCqFHnXf8FjpT MXxRYQ9tHrj/Lojkqh8tvOra2HYQEqECrVf9+ATCAHPRq5ctBn54mBq/86YWqdn1cU6oNr KT/foI3j5FKmu9mdRZ04kF+JZgKJ/qOzzln5uAjmxECTHSDiRZ7wmLllDx7eaA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1742592157; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=+oNseWKuGBEgshNs5P0talv9xg+inN17z1K2AF90QsY=; b=EZS5gE+VsWIJ5vRL3eP5Jndiht64acIE4ql10QAAbAlD7H53yy7I4AqzDTceNhmWCpRnL1 9Xun/0Uq9tAy9gAQ== To: Charlie Jenkins , Paul Walmsley , Palmer Dabbelt , Huacai Chen , WANG Xuerui , Peter Zijlstra , Andy Lutomirski , Alexandre Ghiti , Arnd Bergmann , Albert Ou , Alexandre Ghiti Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, loongarch@lists.linux.dev, Charlie Jenkins Subject: Re: [PATCH v6 0/4] entry: Move ret_from_fork() to C and inline syscall_exit_to_user_mode() In-Reply-To: <20250320-riscv_optimize_entry-v6-0-63e187e26041@rivosinc.com> References: <20250320-riscv_optimize_entry-v6-0-63e187e26041@rivosinc.com> Date: Fri, 21 Mar 2025 22:22:36 +0100 Message-ID: <87frj613kz.ffs@tglx> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain On Thu, Mar 20 2025 at 10:29, Charlie Jenkins wrote: > Similar to commit 221a164035fd ("entry: Move > syscall_enter_from_user_mode() to header file"), move > syscall_exit_to_user_mode() to the header file as well. > > Testing was done with the byte-unixbench [1] syscall benchmark (which > calls getpid) and QEMU. On riscv I measured a 7.09246% improvement, on > x86 a 2.98843% improvement, on loongarch a 6.07954% improvement, and on > s390 a 11.1328% improvement. > > The Intel bot also reported "kernel test robot noticed a 1.9% > improvement of stress-ng.seek.ops_per_sec" [2] > > Since this is on QEMU, I know these numbers are not perfect, but they > show a trend of general improvement across all architectures that use > the generic entry code. This looks sane now. I've bookmarked it as post-merge window material. Thanks, tglx