Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752268AbYCOEc3 (ORCPT ); Sat, 15 Mar 2008 00:32:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750738AbYCOEcU (ORCPT ); Sat, 15 Mar 2008 00:32:20 -0400 Received: from scrub.xs4all.nl ([194.109.195.176]:58738 "EHLO scrub.xs4all.nl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750730AbYCOEcT (ORCPT ); Sat, 15 Mar 2008 00:32:19 -0400 Date: Sat, 15 Mar 2008 05:28:24 +0100 (CET) From: Roman Zippel X-X-Sender: roman@scrub.home To: john stultz cc: lkml , Ingo Molnar Subject: Re: [PATCH 1/5] split clocksource adjustment from clockosurce mult In-Reply-To: <1205553938.6122.79.camel@localhost.localdomain> Message-ID: References: <1205553852.6122.76.camel@localhost.localdomain> <1205553938.6122.79.camel@localhost.localdomain> 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 Content-Length: 789 Lines: 23 Hi, On Fri, 14 Mar 2008, john stultz wrote: > @@ -179,7 +181,7 @@ static inline cycle_t clocksource_read(struct clocksource *cs) > static inline s64 cyc2ns(struct clocksource *cs, cycle_t cycles) > { > u64 ret = (u64)cycles; > - ret = (ret * cs->mult) >> cs->shift; > + ret = (ret * (cs->mult + cs->mult_adj)) >> cs->shift; > return ret; > } This add an extra memory access and extra instruction to a code path, we should keep as short as possible. I'd rather add a mult_raw or mult_org and use that for your next patch. bye, Roman -- 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/