From: Hugh Dickins <hugh@veritas.com>
Extend the warning comment in kmap_types.h: if you add an odd number of new
kmaps, KM_VSTACK0 becomes misaligned on odd numbered cpus. I've not added
a corresponding BUG_ON to entry_trampoline.c, having an aversion to errors
which trigger too early to be seen. We should do better, perhaps #error,
or robustifying the layout; but for now just comment.
include/asm-i386/kmap_types.h | 8 ++++++--
1 files changed, 6 insertions(+), 2 deletions(-)
diff -puN include/asm-i386/kmap_types.h~4g4g-kmap-warning-comments include/asm-i386/kmap_types.h
--- 25/include/asm-i386/kmap_types.h~4g4g-kmap-warning-comments 2003-08-30 15:42:12.000000000 -0700
+++ 25-akpm/include/asm-i386/kmap_types.h 2003-08-30 15:42:12.000000000 -0700
@@ -5,8 +5,8 @@
enum km_type {
/*
- * IMPORTANT: dont move these 3 entries, the virtual stack
- * must be 8K aligned.
+ * IMPORTANT: don't move these 3 entries, and only add entries in
+ * pairs: the 4G/4G virtual stack must be 8K aligned on each cpu.
*/
KM_BOUNCE_READ,
KM_VSTACK1,
@@ -29,6 +29,10 @@ enum km_type {
KM_IRQ1,
KM_SOFTIRQ0,
KM_SOFTIRQ1,
+ /*
+ * Add new entries in pairs:
+ * the 4G/4G virtual stack must be 8K aligned on each cpu.
+ */
KM_TYPE_NR
};
#endif
_