x86: fix stack overflow for large values of MAX_APICS
physid_mask_of_physid() causes a huge stack (12k) to be created if the
number of APICS is large. Replace physid_mask_of_physid() with a
new function that does not create large stacks. This is a problem only
on large x86_64 systems.
this paves the way to increase MAX_APICS.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Cc: linux-mm@kvack.org
Cc: mingo@elte.hu
Cc: tglx@linutronix.de
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/include/asm-x86/mpspec.h b/include/asm-x86/mpspec.h
index 57a991b..b69e7ba 100644
--- a/include/asm-x86/mpspec.h
+++ b/include/asm-x86/mpspec.h
@@ -101,6 +101,7 @@
__physid_mask; \
})
+/* Note: will create very large stack frames if physid_mask_t is big */
#define physid_mask_of_physid(physid) \
({ \
physid_mask_t __physid_mask = PHYSID_MASK_NONE; \
@@ -108,6 +109,12 @@
__physid_mask; \
})
+static inline void physid_set_mask_of_physid(int physid, physid_mask_t *map)
+{
+ physids_clear(*map);
+ physid_set(physid, *map);
+}
+
#define PHYSID_MASK_ALL { {[0 ... PHYSID_ARRAY_SIZE-1] = ~0UL} }
#define PHYSID_MASK_NONE { {[0 ... PHYSID_ARRAY_SIZE-1] = 0UL} }