From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 4380F33FE01; Tue, 16 Dec 2025 07:18:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765869504; cv=none; b=J8mgAzTmlgd+3QiGo3/jCnso/Jqx6MXgR/80h4x4qMWW3HeV0zRjaFVy5PvzDqLKjFETHKkSLj1TMkS/qKpi2uYKw+Y4wMwePHlCuXaGCTuav4l8ygeCzsk0OQq8y/ZY+AC02Klm8OeO1G3XQPpy5hI4JbavLUocvceMIsab7gY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765869504; c=relaxed/simple; bh=AEYGuJEEEYmmmJXdme01cBI/6wB0Oph/64QmJVnKM74=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=Rmg5JlQhfUNRC/j81B8CHSenqIN6mjjMSR6CmuaQOke7ORHQpcVh2k+ZAgmC75tq+/IS0zk+ishbMVT8KFZq1NYcek7+4qfPl7t3LcI2J2d89XC/lB82Xfw8BwM0ngVWnujuAwTU4Z7KQ7npFZzBGyA0re2JGPX/24fqnlqITZc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=dmxmx1Fv; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="dmxmx1Fv" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Sender:Reply-To:Content-ID:Content-Description; bh=VJk0H7KdNrMiS7Qd0o8Uv7On5HN+SnJoFk1KRPPZ2Fk=; b=dmxmx1FvSFfIFY4oXSCMwCTj4E Kdd5MnIDvEdswcqw5moYk5tkJaCZhgePsa7byaHwEzuOA1YaJP3k0KZT7XZCW7dlWb7XoRrEutpzn eeB4duKxzfKocD6L293ywFFHXaK/0UL4/IePKqs0LziPBKuVnzqOYo9BjTCNZANmaYc6bTBZstGTj Nso8/WqieagrlwDHrjeE3Cdr6xAhMuIq2q4RGhYvY07Lab2BHJpGpfTtuqth68r2claDzuWk+FC1l vOY8Qy1a8Z9xztVkBKwBrEujkwweQ46kdN6xKSnJdxS1CEsShyl0rIE9n140ZYx7ooBHd7KcofxHP DUpc3DOg==; Received: from [50.53.43.113] (helo=[192.168.254.34]) by bombadil.infradead.org with esmtpsa (Exim 4.98.2 #2 (Red Hat Linux)) id 1vVPK5-00000004pyN-2hXc; Tue, 16 Dec 2025 07:18:17 +0000 Message-ID: Date: Mon, 15 Dec 2025 23:18:16 -0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [patch V6 07/11] rseq: Implement time slice extension enforcement timer To: Thomas Gleixner , LKML Cc: Mathieu Desnoyers , "Paul E. McKenney" , Boqun Feng , Jonathan Corbet , Prakash Sangappa , Madadi Vineeth Reddy , K Prateek Nayak , Steven Rostedt , Sebastian Andrzej Siewior , Arnd Bergmann , linux-arch@vger.kernel.org, Peter Zijlstra , Ron Geva , Waiman Long References: <20251215155615.870031952@linutronix.de> <20251215155709.068329497@linutronix.de> Content-Language: en-US From: Randy Dunlap In-Reply-To: <20251215155709.068329497@linutronix.de> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Ouch. Would you mind rearranging parts of the first sentence? On 12/15/25 10:24 AM, Thomas Gleixner wrote: > --- a/Documentation/admin-guide/sysctl/kernel.rst > +++ b/Documentation/admin-guide/sysctl/kernel.rst > @@ -1228,6 +1228,14 @@ reboot-cmd (SPARC only) > ROM/Flash boot loader. Maybe to tell it what to do after > rebooting. ??? > > +rseq_slice_extension_nsec > +========================= > + > +A task can request to delay its scheduling if it is in a critical section > +via the prctl(PR_RSEQ_SLICE_EXTENSION_SET) mechanism. This sets the maximum > +allowed extension in nanoseconds before scheduling of the task is enforced. > +Default value is 30000ns (30us). The possible range is 10000ns (10us) to > +50000ns (50us). Maybe A task that is in a critical section can request to delay its scheduling via the prctl(PR_RSEQ_SLICE_EXTENSION_SET) mechanism. -- ~Randy