mm: mark fault_around_bytes __read_mostly

fault_around_bytes can only be changed via debugfs.  Let's mark it
read-mostly.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Suggested-by: David Rientjes <rientjes@google.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 1 deletions

diff --git a/mm/memory.c b/mm/memory.c
index dc47261c4686..5596d77e8656 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2766,7 +2766,8 @@ void do_set_pte(struct vm_area_struct *vma, unsigned long address,
         update_mmu_cache(vma, address, pte);
 }
 
-static unsigned long fault_around_bytes = rounddown_pow_of_two(65536);
+static unsigned long fault_around_bytes __read_mostly =
+        rounddown_pow_of_two(65536);
 
 #ifdef CONFIG_DEBUG_FS
 static int fault_around_bytes_get(void *data, u64 *val)