From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 16 Apr 2008 11:39:36 -0500 From: Jack Steiner Subject: [PATCH] - Increase MAX_APICS for large configs Message-ID: <20080416163936.GA23099@sgi.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Sender: owner-linux-mm@kvack.org Return-Path: To: mingo@elte.hu, tglx@linutronix.de Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: Increase the maximum number of apics when running very large configurations. This patch has no affect on most systems. Signed-off-by: Jack Steiner --- I think this area of the code will be substantially changed when the full x2apic patch is available. In the meantime, this seems like an acceptible alternative. The patch has no effect on any 32-bit kernel. It adds ~4k to the size of 64-bit kernels but only if NR_CPUS > 255. include/asm-x86/mpspec_def.h | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) Index: linux/include/asm-x86/mpspec_def.h =================================================================== --- linux.orig/include/asm-x86/mpspec_def.h 2008-03-29 06:45:28.000000000 -0500 +++ linux/include/asm-x86/mpspec_def.h 2008-03-31 14:17:01.000000000 -0500 @@ -17,10 +17,11 @@ # define MAX_MPC_ENTRY 1024 # define MAX_APICS 256 #else -/* - * A maximum of 255 APICs with the current APIC ID architecture. - */ -# define MAX_APICS 255 +# if NR_CPUS <= 255 +# define MAX_APICS 255 +# else +# define MAX_APICS 32768 +# endif #endif struct intel_mp_floating { -- 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: email@kvack.org