From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Fri, 4 Jul 2003 12:16:41 -0400 (EDT) From: Zwane Mwaikambo Subject: Re: 2.5.74-mm1 fails to boot due to APIC trouble, 2.5.73mm3 works. In-Reply-To: <13170000.1057335490@[10.10.2.4]> Message-ID: References: <20030703023714.55d13934.akpm@osdl.org> <3F054109.2050100@aitel.hist.no><20030704093531.GA26348@holomorphy.com> <20030704095004.GB26348@holomorphy.com><7910000.1057333295@[10.10.2.4]> <13170000.1057335490@[10.10.2.4]> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: "Martin J. Bligh" Cc: William Lee Irwin III , Helge Hafting , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: On Fri, 4 Jul 2003, Martin J. Bligh wrote: > > No, the problem is no space for physical ids in cpumask bitmaps, this > > could manifest itself later on unless we fix it now. > > Ugh, are you saying the cpumask stuff shrinks masks to < 32 bits if > NR_CPUS is low enough? If so, I can see more point to the patch, but > it still seems like violent overkill. Stopping it doing that would > probably fix it ... I can't imagine it buys you much. Hmm i hope not, Bill can you verify that? Looking at the source it doesn't appear to be so; #define BITS_TO_LONGS(bits) \ (((bits)+BITS_PER_LONG-1)/BITS_PER_LONG) #define DECLARE_BITMAP(name,bits) \ unsigned long name[BITS_TO_LONGS(bits)] > phys_cpu_present_map started off as an unsigned long, and I reused it > in a fairly twisted way for NUMA-Q. As it's an array that's bounded > by apic space, using the bios_cpu_apicid method that summit uses > would be a much cleaner fix, and just leave the old one as a long > bitmask like it used to be - which is fine for non- clustered apic > systems, and saves inventing a whole new data type. See the > cpu_present_to_apicid abstraction. Thanks i'll have a look. -- function.linuxpower.ca -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: aart@kvack.org