mm: properly separate the bloated ptl from the regular case

Use kernel/bounds.c to convert build-time spinlock_t size check into a
preprocessor symbol and apply that to properly separate the page::ptl
situation.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/kernel/bounds.c b/kernel/bounds.c
index e8ca97b5c386..578782ef6ae1 100644
--- a/kernel/bounds.c
+++ b/kernel/bounds.c
@@ -11,6 +11,7 @@
 #include <linux/kbuild.h>
 #include <linux/page_cgroup.h>
 #include <linux/log2.h>
+#include <linux/spinlock.h>
 
 void foo(void)
 {
@@ -21,5 +22,6 @@ void foo(void)
 #ifdef CONFIG_SMP
         DEFINE(NR_CPUS_BITS, ilog2(CONFIG_NR_CPUS));
 #endif
+        DEFINE(BLOATED_SPINLOCKS, sizeof(spinlock_t) > sizeof(int));
         /* End of constants */
 }