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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 {

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