From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932559Ab0JLQ5R (ORCPT ); Tue, 12 Oct 2010 12:57:17 -0400 Received: from www.tglx.de ([62.245.132.106]:44930 "EHLO www.tglx.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753624Ab0JLQ5P (ORCPT ); Tue, 12 Oct 2010 12:57:15 -0400 Date: Tue, 12 Oct 2010 18:56:23 +0200 (CEST) From: Thomas Gleixner To: Andi Kleen cc: Tim Pepper , Marcio Saito , John Stultz , Jiri Slaby , Peter Zijlstra , x86@kernel.org, LKML , Frederic Weisbecker , Ingo Molnar , Paul Mackerras , "H. Peter Anvin" , Avantika Mathur , linuxppc-dev@lists.ozlabs.org, jblunck@infradead.org Subject: Re: [RFC] [PATCH] allow low HZ values? In-Reply-To: <871v7v32kn.fsf@basil.nowhere.org> Message-ID: References: <20101011201121.GA953@tpepper-t61p.dolavim.us> <871v7v32kn.fsf@basil.nowhere.org> User-Agent: Alpine 2.00 (LFD 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 12 Oct 2010, Andi Kleen wrote: > Thomas Gleixner writes: > > We have told HPC folks for years that we need a kind of "NOHZ" mode > > for HPC where we can transparently switch off the tick when only one > > user space bound thread is active and switch back to normal once this > > thing terminates or goes into the kernel via a syscall. Sigh, nothing > > happened ever except for repeating the same crap patches over and > > over. > > Jan Blunck posted a patch for this exactly few months ago. > Unfortunately it didn't get the accounting right, but other than > that it seemed like a reasonable starting point. Unfortunately it did not get a lot of other things right either. Thanks, tglx