Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759265Ab3EGJJY (ORCPT ); Tue, 7 May 2013 05:09:24 -0400 Received: from cam-admin0.cambridge.arm.com ([217.140.96.50]:34055 "EHLO cam-admin0.cambridge.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759160Ab3EGJJW (ORCPT ); Tue, 7 May 2013 05:09:22 -0400 Date: Tue, 7 May 2013 10:08:49 +0100 From: Will Deacon To: Christopher Covington Cc: "linux-arm-kernel@lists.infradead.org" , Marc Zyngier , "linux-kernel@vger.kernel.org" Subject: Re: [RFC PATCH 0/2] ARM: Remove any correlation between IPC and BogoMips value Message-ID: <20130507090849.GC25387@mudshark.cambridge.arm.com> References: <1367602547-19322-1-git-send-email-will.deacon@arm.com> <5187EFF3.6010005@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5187EFF3.6010005@codeaurora.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1418 Lines: 32 On Mon, May 06, 2013 at 07:01:23PM +0100, Christopher Covington wrote: > Hi Will, > > On 05/03/2013 01:35 PM, Will Deacon wrote: > > Hi all, > > > > This small patch set may look a little over a month late, but there is a > > serious reason for posting it. > > > > When I moved the ARM delay loop over to using the architected timers > > rather than the CPU spinning loop (which has all the problems associated > > with cpu frequency scaling and what-not) I thought I was doing something > > useful for the port. However, it turns out that a surprising number of > > people have complained, and continue to complain, about the drop in > > their `BogoMIPs score'. > > Have you considered adding the old code back in, but in a form that's not at > all referenced by the delay loop code and just calculates CPU-based bogomips? That seems like a lot of effort in order to preserve something that isn't even meaningful. We might be better just zeroing the value, but then we'll inevitably get bug reports of it being `wrong'. Plus, the calibration during boot introduces a brief delay when onlining each core whereas this can be skipped when using a constant timer. Will -- 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/