Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750802AbWIHLIe (ORCPT ); Fri, 8 Sep 2006 07:08:34 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750805AbWIHLIe (ORCPT ); Fri, 8 Sep 2006 07:08:34 -0400 Received: from gate.crashing.org ([63.228.1.57]:14208 "EHLO gate.crashing.org") by vger.kernel.org with ESMTP id S1750802AbWIHLId (ORCPT ); Fri, 8 Sep 2006 07:08:33 -0400 Subject: Re: [PATCH] FRV: do_gettimeofday() should no longer use tickadj From: Benjamin Herrenschmidt To: David Howells Cc: Ingo Molnar , john stultz , Adrian Bunk , Andrew Morton , Arjan van de Ven , linux-kernel@vger.kernel.org, Jeff Garzik , netdev@vger.kernel.org, Thomas Gleixner In-Reply-To: <10720.1157711152@warthog.cambridge.redhat.com> References: <1157669602.22705.326.camel@localhost.localdomain> <1157583693.22705.254.camel@localhost.localdomain> <20060906125626.GA3718@elte.hu> <20060906094301.GA8694@elte.hu> <1157507203.2222.11.camel@localhost> <20060905132530.GD9173@stusta.de> <20060901015818.42767813.akpm@osdl.org> <6260.1157470557@warthog.cambridge.redhat.com> <8430.1157534853@warthog.cambridge.redhat.com> <13982.1157545856@warthog.cambridge.redhat.com> <17274.1157553962@warthog.cambridge.redhat.com> <8934.1157622928@warthog.cambridge.redhat.com> <10720.1157711152@warthog.cambridge.redhat.com> Content-Type: text/plain Date: Fri, 08 Sep 2006 21:05:05 +1000 Message-Id: <1157713505.31071.84.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.6.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1436 Lines: 30 On Fri, 2006-09-08 at 11:25 +0100, David Howells wrote: > Benjamin Herrenschmidt wrote: > > > No, you do a chain handler. Look at how I do it in > > arch/powerpc/platform/pseries/setup.c for example. It's actually > > trivial. You install a special flow handler (which means that there is > > very little overhead, almost none, from the toplevel irq to the chained > > irq). You can _also_ if you want just install an IRQ handler for the > > cascaded controller and call generic_handle_irq (rather than __do_IRQ) > > from it, but that has more overhead. A chained handler completely > > relaces the flow handler for the cascade, and thus, if you don't need > > all of the nits and bits of the other flow handlers for your cascade, > > you can speed things up by hooking at that level. > > Please update Documentation/DocBook/genericirq.tmpl. That doesn't mention it. I must admit I haven't read the documentation :) I looked at the code/patches when genirq was posted and did my powerpc implementation based on my understanding of the code and discussions with Thomas and Ingo. I'll have a look at the doc next week and see if I can improve it. Cheers, 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/