From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Message-ID: <17998.28659.702653.237011@cargo.ozlabs.ibm.com> Date: Sat, 19 May 2007 13:33:07 +1000 From: Paul Mackerras To: Daniel Walker Subject: Re: [PATCH 2.6.21-rt2] PowerPC: decrementer clockevent driver In-Reply-To: <1179502773.20519.56.camel@imap.mvista.com> References: <200705172142.26739.sshtylyov@ru.mvista.com> <8E44DB06-767D-4864-8D2C-6132E4D4370B@kernel.crashing.org> <464C99FF.8080404@ru.mvista.com> <135307ED-7125-4859-8594-4B5B900D92D6@kernel.crashing.org> <1179500217.20519.53.camel@imap.mvista.com> <464DC0DC.7050809@ru.mvista.com> <1179502773.20519.56.camel@imap.mvista.com> Cc: linuxppc-dev@ozlabs.org, tglx@linutronix.de, mingo@elte.hu, linux-kernel@vger.kernel.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Daniel Walker writes: > On Fri, 2007-05-18 at 19:06 +0400, Sergei Shtylyov wrote: > > Well, the decrementer frequency may change, at least in theory (if the bus > > clock changes). > > Does that happen very often? If it did, gettimeofday would start reporting seriously wrong values, since the timebase and the decrementer count at the same rate, and we don't have any provision for fixing things up if that rate changed. Fortunately there are no powerpc platforms where the rate is variable. Paul.