Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264610AbUF1B2R (ORCPT ); Sun, 27 Jun 2004 21:28:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264625AbUF1B2R (ORCPT ); Sun, 27 Jun 2004 21:28:17 -0400 Received: from disk.smurf.noris.de ([192.109.102.53]:31369 "EHLO server.smurf.noris.de") by vger.kernel.org with ESMTP id S264610AbUF1B2P (ORCPT ); Sun, 27 Jun 2004 21:28:15 -0400 From: "Matthias Urlichs" Date: Mon, 28 Jun 2004 03:24:07 +0200 To: Chris Wedgwood Cc: linux-kernel@vger.kernel.org Subject: Re: [parisc-linux] Re: [PATCH] Fix the cpumask rewrite Message-ID: <20040628012407.GC4648@kiste> References: <1088266111.1943.15.camel@mulgrave> <20040626221802.GA12296@taniwha.stupidest.org> <1088290477.3790.2.camel@localhost.localdomain> <20040627000541.GA13325@taniwha.stupidest.org> <20040627224115.GA22532@taniwha.stupidest.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20040627224115.GA22532@taniwha.stupidest.org> User-Agent: Mutt/1.5.6+20040523i X-Smurf-Spam-Score: -3.8 (---) X-Smurf-Spam-Report: Spam detection software, running on the system "server.smurf.noris.de", has identified this incoming email as possible spam. The original message has been attached to this so you can view it (if it isn't spam) or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: Hi, Chris Wedgwood: > On Sun, Jun 27, 2004 at 02:00:03PM +0200, Matthias Urlichs wrote: > > > > > #define jiffies __get_jiffies() > > > > Well, I have that but it's only part of the story. > True. [...] Content analysis details: (-3.8 points, 10.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -4.9 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] 1.1 AWL AWL: From: address is in the auto white-list Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1086 Lines: 32 Hi, Chris Wedgwood: > On Sun, Jun 27, 2004 at 02:00:03PM +0200, Matthias Urlichs wrote: > > > > > #define jiffies __get_jiffies() > > > > Well, I have that but it's only part of the story. > True. > As Alan pointed out a suitable API could also make it easier to work > towards a clock-less system for embedded targets. > Well, drivers do need some way of timing things, else they wouldn't read jiffies in the first place. So, at minimum, an embedded system would need a way to trigger a timeout at some specified time in the future. A simple __get_jiffies() implementation could just set up a 1/HZ-second timer (and busy-wait for it, and increase its internal jiffies counter) every tenth call or so. That would probably slow down the whole system somewhat, but I'd assume it'd mostly work. -- Matthias Urlichs - 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/