Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759649AbcCEI3m (ORCPT ); Sat, 5 Mar 2016 03:29:42 -0500 Received: from www.linutronix.de ([62.245.132.108]:39294 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751478AbcCEI3e (ORCPT ); Sat, 5 Mar 2016 03:29:34 -0500 Date: Sat, 5 Mar 2016 09:28:10 +0100 (CET) From: Thomas Gleixner To: Andy Lutomirski cc: Rasmus Villemoes , Andy Lutomirski , "linux-kernel@vger.kernel.org" , X86 ML Subject: Re: soft lockup when passing vvar address to write(2) In-Reply-To: Message-ID: References: <87wppj4198.fsf@rasmusvillemoes.dk> User-Agent: Alpine 2.11 (DEB 23 2013-08-11) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 474 Lines: 13 On Fri, 4 Mar 2016, Andy Lutomirski wrote: > Thomas, I still think we should consider just deleting the HPET vclock > code and accept the syscall overhead on systems that are stuck using > HPET. If fast syscalls are available (which should include every > system with HPET, unless there are some 32-bit AMD systems lying > around), then the overhead in a syscall is *tiny* compared to the code > of the HPET read itself. No objection from my side, really. Thanks, tglx