Messages in this thread Patch in this message | | | Date | Mon, 16 Jun 2008 12:09:10 -0500 | From | Jack Steiner <> | Subject | [PATCH] - Increase MAX_APICS for very large x86_64 configs |
| |
Increase the maximum number of apics when running very large configurations. This patch has no affect on most systems.
Signed-off-by: Jack Steiner <steiner@sgi.com>
---
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.
This is a repost of an earlier patch (4/16) that was implicated in a random-qa failure. I have not been able to reproduce the failure using the same boot args & config. Best guess is that some other patch caused random data corruption & this patch was a victim.
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 2008-06-08 09:05:51.140046529 -0500 +++ linux/include/asm-x86/mpspec_def.h 2008-06-08 09:05:55.244550306 -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 {
| |