mm/debug-pagealloc: make debug-pagealloc boottime configurable
Now, we have prepared to avoid using debug-pagealloc in boottime. So
introduce new kernel-parameter to disable debug-pagealloc in boottime, and
makes related functions to be disabled in this case.
Only non-intuitive part is change of guard page functions. Because guard
page is effective only if debug-pagealloc is enabled, turning off
according to debug-pagealloc is reasonable thing to do.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Jungsoo Son <jungsoo.son@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index e0a39d3..303d385 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -425,15 +425,35 @@
#ifdef CONFIG_DEBUG_PAGEALLOC
unsigned int _debug_guardpage_minorder;
+bool _debug_pagealloc_enabled __read_mostly;
bool _debug_guardpage_enabled __read_mostly;
+static int __init early_debug_pagealloc(char *buf)
+{
+ if (!buf)
+ return -EINVAL;
+
+ if (strcmp(buf, "on") == 0)
+ _debug_pagealloc_enabled = true;
+
+ return 0;
+}
+early_param("debug_pagealloc", early_debug_pagealloc);
+
static bool need_debug_guardpage(void)
{
+ /* If we don't use debug_pagealloc, we don't need guard page */
+ if (!debug_pagealloc_enabled())
+ return false;
+
return true;
}
static void init_debug_guardpage(void)
{
+ if (!debug_pagealloc_enabled())
+ return;
+
_debug_guardpage_enabled = true;
}