Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750777AbWIHKbP (ORCPT ); Fri, 8 Sep 2006 06:31:15 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750774AbWIHKbP (ORCPT ); Fri, 8 Sep 2006 06:31:15 -0400 Received: from mx1.redhat.com ([66.187.233.31]:718 "EHLO mx1.redhat.com") by vger.kernel.org with ESMTP id S1750719AbWIHKbN (ORCPT ); Fri, 8 Sep 2006 06:31:13 -0400 From: David Howells In-Reply-To: <1157669602.22705.326.camel@localhost.localdomain> 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> To: Benjamin Herrenschmidt Cc: David Howells , 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 Subject: Re: [PATCH] FRV: do_gettimeofday() should no longer use tickadj X-Mailer: MH-E 8.0; nmh 1.1; GNU Emacs 22.0.50 Date: Fri, 08 Sep 2006 11:25:52 +0100 Message-ID: <10720.1157711152@warthog.cambridge.redhat.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1064 Lines: 21 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. David - 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/