From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Wilcox Subject: Re: [parisc-linux] Generic IRQ support Date: Fri, 10 Dec 2004 13:10:28 +0000 Message-ID: <20041210131028.GA11305@parcelfarce.linux.theplanet.co.uk> References: <20041209152944.GP10881@parcelfarce.linux.theplanet.co.uk> <20041210055140.GC26739@colo.lackof.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: parisc-linux@parisc-linux.org, Matthew Wilcox To: Grant Grundler Return-Path: In-Reply-To: <20041210055140.GC26739@colo.lackof.org> List-Id: parisc-linux developers list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: parisc-linux-bounces@lists.parisc-linux.org On Thu, Dec 09, 2004 at 10:51:40PM -0700, Grant Grundler wrote: > Yes - it's certainly feasible. > I've proposed something similar several years ago: > http://lists.parisc-linux.org/pipermail/parisc-linux/2000-October/009640.html > > Last year Thibaut Varene and I even took a run at it. > Our goal was to pickup/add generic support for IRQ affinity. > We got ~60% done after a few monthes but ran out of time. I found http://lists.parisc-linux.org/pipermail/parisc-linux/2004-August/024593.html but I couldn't find the patch that was referenced there. > > Machines with iosapic have one CPU interrupt per iosapic interrupt, > > so we can get rid of the hierarchy. The iosapic still needs to be told > > that we've finished processing the interrupt, but that can be done by > > the ->end method. > > We can't entirely get rid of the hierarchy. > There are configurations where we might have to share a CPU EIR. > Since N-class is working now, I'm mostly concerned about it on that > class of platform. Especially if we want to support MSI or MSI-X. Once we start to hit problems like this (more than 64 interrupts per CPU), we can write some code to reintroduce a hierarchy, I guess. > You probably want to look at the source tree from Thibaut since > that's basically the same approach we took then...most of the > changes should still apply. > Please poke (gently) if I can help. If you could find that work ... -- "Next the statesmen will invent cheap lies, putting the blame upon the nation that is attacked, and every man will be glad of those conscience-soothing falsities, and will diligently study them, and refuse to examine any refutations of them; and thus he will by and by convince himself that the war is just, and will thank God for the better sleep he enjoys after this process of grotesque self-deception." -- Mark Twain _______________________________________________ parisc-linux mailing list parisc-linux@lists.parisc-linux.org http://lists.parisc-linux.org/mailman/listinfo/parisc-linux