From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1767176AbXDEVax (ORCPT ); Thu, 5 Apr 2007 17:30:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1767326AbXDEVax (ORCPT ); Thu, 5 Apr 2007 17:30:53 -0400 Received: from homer.mvista.com ([63.81.120.158]:35224 "EHLO gateway-1237.mvista.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1767176AbXDEVaw (ORCPT ); Thu, 5 Apr 2007 17:30:52 -0400 Subject: Re: [PATCH] timekeeping: drop irq-context clocksource polling From: Daniel Walker To: john stultz Cc: linux-kernel@vger.kernel.org, akpm@linux-foundation.org, mingo@elte.hu In-Reply-To: <1175808319.28526.26.camel@localhost> References: <20070405210316.785839431@mvista.com> <1175808319.28526.26.camel@localhost> Content-Type: text/plain Date: Thu, 05 Apr 2007 14:29:27 -0700 Message-Id: <1175808567.15973.137.camel@imap.mvista.com> Mime-Version: 1.0 X-Mailer: Evolution 2.8.2.1 (2.8.2.1-3.fc6) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2007-04-05 at 14:25 -0700, john stultz wrote: > On Thu, 2007-04-05 at 14:03 -0700, Daniel Walker wrote: > > Before this change the timekeeping code would poll the clocksource > > list every interrupt. This changes that so the clocksource list is > > only checked when there has been and update, and no longer checks > > in interrupt context. > > > > This also has a few small space and line cleanups. > > > > Boot tested on i386, compile tested on x86_64 .. However, I couldn't > > find a !GENERIC_TIME that compiled without this change so it's untested.. > > > > Signed-Off-By: Daniel Walker > > Err.. I think you need to be holding a write on the xtime_lock (as is > done before calling update_wall_time()) when changing the clocksource. I added a write_seqlock_irqsave() on xtime_lock in change_clocksource() .. Did I need more (different) protection than that? Daniel