From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e4.ny.us.ibm.com (e4.ny.us.ibm.com [32.97.182.144]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "e4.ny.us.ibm.com", Issuer "Equifax" (verified OK)) by ozlabs.org (Postfix) with ESMTP id 1EABBDE027 for ; Wed, 7 Mar 2007 15:54:24 +1100 (EST) Received: from d01relay02.pok.ibm.com (d01relay02.pok.ibm.com [9.56.227.234]) by e4.ny.us.ibm.com (8.13.8/8.13.8) with ESMTP id l274sFUS019693 for ; Tue, 6 Mar 2007 23:54:15 -0500 Received: from d01av02.pok.ibm.com (d01av02.pok.ibm.com [9.56.224.216]) by d01relay02.pok.ibm.com (8.13.8/8.13.8/NCO v8.3) with ESMTP id l274sFCu302592 for ; Tue, 6 Mar 2007 23:54:15 -0500 Received: from d01av02.pok.ibm.com (loopback [127.0.0.1]) by d01av02.pok.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id l274sEDI024128 for ; Tue, 6 Mar 2007 23:54:14 -0500 Date: Wed, 7 Mar 2007 10:23:41 +0530 From: Mohan Kumar M To: Michael Ellerman Subject: Re: [PATCH] Fix interrupt distribution in ppc970 Message-ID: <20070307045341.GG7476@in.ibm.com> References: <20061208045537.GA14626@in.ibm.com> <17798.6928.378248.28903@cargo.ozlabs.ibm.com> <20061218105706.GB3911@in.ibm.com> <20070306135754.GB7476@in.ibm.com> <1173190615.4675.30.camel@concordia.ozlabs.ibm.com> <20070306165529.GD7476@in.ibm.com> <1173202634.4675.37.camel@concordia.ozlabs.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1173202634.4675.37.camel@concordia.ozlabs.ibm.com> Cc: ppcdev , Paul Mackerras , fastboot@lists.osdl.org Reply-To: mohan@in.ibm.com List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Tue, Mar 06, 2007 at 06:37:14PM +0100, Michael Ellerman wrote: > On Tue, 2007-03-06 at 22:25 +0530, Mohan Kumar M wrote: > > On Tue, Mar 06, 2007 at 03:16:55PM +0100, Michael Ellerman wrote: > > > First, I don't know why we keep telling people to use maxcpus=1 for > > > kexec/kdump - it's causing bugs, and I don't know of any that it fixes? > > > > Some distros want to use maxcpus=1 for kdump. > > Yeah OK. > > > > Second, the way you've written this is not so good. The xics code should > > > not be checking that "maxcpus" exists on the command line, it should be > > > checking that the distrib server points to a cpu that is online - using > > > cpu_online() etc. > > > > > > > In get_irq_server function in xics.c, "noirqdistrib" command line > > parameter is indirectly checked for routing the interrupts either to a > > specific cpu or to all cpus. So I think checking for maxcpus= command > > line parameter in xics.c is not a problem. > > No, it checks a flag, it doesn't run strstr on the saved command line. > What if I use a flag (or existing global variable if any) to check for the presence of maxcpus kernel paramter? > > Also during the xics_init_IRQ function other cpus (secondary cpus) will > > not be online, they are made online at a later stage. So using > > cpu_online() function at xics_init_IRQ will return true only for boot > > cpu id. > > OK, so you should be able to use cpus possible map or something similar. > Hmm, I think cpus possible map will have an entry for the offline cpu also. > cheers > > -- > Michael Ellerman > OzLabs, IBM Australia Development Lab > > wwweb: http://michael.ellerman.id.au > phone: +61 2 6212 1183 (tie line 70 21183) > > We do not inherit the earth from our ancestors, > we borrow it from our children. - S.M.A.R.T Person