Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261593AbVASFpq (ORCPT ); Wed, 19 Jan 2005 00:45:46 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261595AbVASFpq (ORCPT ); Wed, 19 Jan 2005 00:45:46 -0500 Received: from gate.crashing.org ([63.228.1.57]:39650 "EHLO gate.crashing.org") by vger.kernel.org with ESMTP id S261593AbVASFpk (ORCPT ); Wed, 19 Jan 2005 00:45:40 -0500 Subject: Re: [PATCH] dynamic tick patch From: Benjamin Herrenschmidt To: Tony Lindgren Cc: Pavel Machek , George Anzinger , john stultz , Andrea Arcangeli , Zwane Mwaikambo , Con Kolivas , Martin Schwidefsky , Linux Kernel list In-Reply-To: <20050119052118.GA19591@atomide.com> References: <20050119000556.GB14749@atomide.com> <1106108467.4500.169.camel@gaston> <20050119050701.GA19542@atomide.com> <20050119052118.GA19591@atomide.com> Content-Type: text/plain Date: Wed, 19 Jan 2005 16:44:26 +1100 Message-Id: <1106113466.4533.178.camel@gaston> Mime-Version: 1.0 X-Mailer: Evolution 2.0.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1347 Lines: 33 On Tue, 2005-01-18 at 21:21 -0800, Tony Lindgren wrote: > * Tony Lindgren [050118 21:08]: > > * Benjamin Herrenschmidt [050118 20:22]: > > > > > > BTW. Is it possible, when entering the "idle" loop, to quickly know an > > > estimate of when the next tick shoud actually kick in ? > > > > Yes, see next_timer_interrupt() for that. > > Hmmm, or maybe you mean _quick_estimate_ instead of > next_timer_interrupt()? > > I don't think there's any faster way to estimate the skippable ticks > without going through the list like next_timer_interrupt already does. > Does anybody have any ideas for that? No, that's fine, we already have to call it before entering the PM state, so I'll just pass it along and, at the low level, decide how deep to sleep based on that. I think I should also add some stats on the amount of interrupts, since it would be fairly inefficient to keep entering deep PM state on a machine with typically little timer interrupts but high HW interrupt (Rusty mentions case of packet forwarding routers or that kind of thing) Ben. - 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/