From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759027AbaD3NBl (ORCPT ); Wed, 30 Apr 2014 09:01:41 -0400 Received: from www.linutronix.de ([62.245.132.108]:51114 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758707AbaD3NBk (ORCPT ); Wed, 30 Apr 2014 09:01:40 -0400 Message-ID: <5360F42C.9080401@linutronix.de> Date: Wed, 30 Apr 2014 15:01:32 +0200 From: Sebastian Andrzej Siewior User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Icedove/24.4.0 MIME-Version: 1.0 To: Will Deacon CC: Russell King , John Stultz , Theodore Ts o , Stephen Boyd , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" Subject: Re: [RFC PATCH] sched_clock: also call register_current_timer_delay() if possible References: <1398860614-29469-1-git-send-email-bigeasy@linutronix.de> <20140430124800.GC21876@arm.com> In-Reply-To: <20140430124800.GC21876@arm.com> X-Enigmail-Version: 1.6 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/30/2014 02:48 PM, Will Deacon wrote: > Hi Sebastian, Hi Will, > As long as sched_clock is guaranteed to be a fixed frequency, always-on > clocksource then this could work, but it removes the flexibility of having > a separate delay clock and sched clock (is this useful?). > Looking at your patch, I noticed that we need to extend the > register_current_timer_delay function to deal with clocks that aren't as > wide as cycle_t, otherwise we don't delay() for long enough when the clock > overflows (this is potentially already an issue for architected timers < > 64-bit). Could you cook a patch for that please? Sure, I would change the type from long to u64 and fix all users. Would that be okay for you? > > Will Sebastian