From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 3A5F55D485; Fri, 23 Feb 2024 10:54:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708685675; cv=none; b=mXrVd7l7BkB9h9PqoLKic9xXXbGEulxBQqLxJd42mWLNP6IH3qbniEcxbuIf8OgZLsfyrwo+1/dWXkPyyxjvwOnFZJ9UqbqXQoQXY/nk3zcDTp6mUQ0tJHUM7flkRJqhxRBmix7eGMDvUKJ7Ip6y0vUDfr7GuROpNia+77y2AUc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708685675; c=relaxed/simple; bh=9dVfvruGdbgHremfgUv+pqbA8QF04s4I7tA2NqshGxU=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ZL87DyD6cXObvnHBLJGhxfAAKNFFgf+S2Bx5Rv55pFum3LZzxrp4x1Am++KSGpgDllF4/grdc9LaiK1ulwG4tATuItBdHEIfMlIQZzvERZ/vOI+sDsIF8Y9vRRCfCsHrF/OH/H1giUnAR57sSKW2VFsQfK/bXP9XQSWiJSf29yo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id E64B91596; Fri, 23 Feb 2024 02:55:10 -0800 (PST) Received: from FVFF77S0Q05N (unknown [10.57.66.180]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 3A6DE3F762; Fri, 23 Feb 2024 02:54:31 -0800 (PST) Date: Fri, 23 Feb 2024 10:54:28 +0000 From: Mark Rutland To: "Paul E. McKenney" Cc: rcu@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@meta.com, rostedt@goodmis.org, ankur.a.arora@oracle.com, tglx@linutronix.de Subject: Re: [PATCH rcu 0/4] Refactor TASKS_RCU for lazy preemption Message-ID: References: <8c938bd5-6d62-4eff-9289-13b0d7ae8e17@paulmck-laptop> Precedence: bulk X-Mailing-List: rcu@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <8c938bd5-6d62-4eff-9289-13b0d7ae8e17@paulmck-laptop> On Thu, Feb 22, 2024 at 04:26:18PM -0800, Paul E. McKenney wrote: > Hello! Hi! > This series refactors the NEED_TASKS_RCU option so that the conditional > processing is in one place in kernel/rcu/Kconfig. This makes it easier > to make sure that Tasks RCU is enabled in PREEMPT_AUTO kernels, given > that such kernels are preemptible, even if only lazily so. After all, > it takes only one lazy preemption from a trampoline to significantly > degrade your kernel's actuarial statistics. > > 1. Create NEED_TASKS_RCU to factor out enablement logic. > > 2. Select new NEED_TASKS_RCU Kconfig option. > > 3. Select new NEED_TASKS_RCU Kconfig option. > > 4. Select new NEED_TASKS_RCU Kconfig option. For the series: Acked-by: Mark Rutland Mark.