Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753741AbYJCTPp (ORCPT ); Fri, 3 Oct 2008 15:15:45 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752061AbYJCTPh (ORCPT ); Fri, 3 Oct 2008 15:15:37 -0400 Received: from relais.videotron.ca ([24.201.245.36]:24329 "EHLO relais.videotron.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751977AbYJCTPg (ORCPT ); Fri, 3 Oct 2008 15:15:36 -0400 MIME-version: 1.0 Content-transfer-encoding: 7BIT Content-type: TEXT/PLAIN; charset=US-ASCII Date: Fri, 03 Oct 2008 15:15:24 -0400 (EDT) From: Nicolas Pitre X-X-Sender: nico@xanadu.home To: David Howells Cc: Peter Zijlstra , torvalds@osdl.org, akpm@linux-foundation.org, linux-am33-list@redhat.com, lkml Subject: Re: [PATCH 1/2] MN10300: Move asm-arm/cnt32_to_63.h to include/linux/ In-reply-to: <1703.1222986215@redhat.com> Message-id: References: <20080924164826.14867.63020.stgit@warthog.procyon.org.uk> <1222426580.16700.258.camel@lappy.programming.kicks-ass.net> <1222431635.16700.278.camel@lappy.programming.kicks-ass.net> <29968.1222871650@redhat.com> <1703.1222986215@redhat.com> User-Agent: Alpine 2.00 (LFD 1167 2008-08-23) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 978 Lines: 25 On Thu, 2 Oct 2008, David Howells wrote: > Nicolas Pitre wrote: > > > Oh, that's a possibility. In that case __m_cnt_hi will be reverted to a > > previous state just like if cnt32_to_63() has not been called yet since > > the new half period. And a subsequent call will fix that again. > > Surely that's not good enough. There's a 50% chance that reversion to a > previous state will result in an extra increment of the __m_cnt_hi on the next > call. If so then you're using this interface in an inappropriate way. The _absolute_ minimum frequency with which this should be fully executed is once per half period of the base counter. I hope that in practice it happens far more often than that. Nicolas -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/