sound: query dynamic DEBUG_PAGEALLOC setting

We can disable debug_pagealloc processing even if the code is compiled with CONFIG_DEBUG_PAGEALLOC. This patch changes the code to query whether it is enabled or not in runtime. [[email protected]: export _debug_pagealloc_enabled to modules] Signed-off-by: Joonsoo Kim <[email protected]> Acked-by: David Rientjes <[email protected]> Acked-by: Takashi Iwai <[email protected]> Cc: Benjamin Herrenschmidt <[email protected]> Cc: Chris Metcalf <[email protected]> Cc: Christian Borntraeger <[email protected]> Cc: Christoph Lameter <[email protected]> Cc: Pekka Enberg <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
lucamilanesio · Mar 17, 2016 · 505f6d2 · 505f6d2
1 parent 922d566
commit 505f6d2
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Showing 2 changed files with 6 additions and 4 deletions.
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
@@ -498,6 +498,7 @@ void prep_compound_page(struct page *page, unsigned int order)
 unsigned int _debug_guardpage_minorder;
 bool _debug_pagealloc_enabled __read_mostly
 			= IS_ENABLED(CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT);
+EXPORT_SYMBOL(_debug_pagealloc_enabled);
 bool _debug_guardpage_enabled __read_mostly;
 
 static int __init early_debug_pagealloc(char *buf)

diff --git a/sound/drivers/pcsp/pcsp.c b/sound/drivers/pcsp/pcsp.c
@@ -14,6 +14,7 @@
 #include <linux/input.h>
 #include <linux/delay.h>
 #include <linux/bitops.h>
+#include <linux/mm.h>
 #include "pcsp_input.h"
 #include "pcsp.h"
 
@@ -148,11 +149,11 @@ static int alsa_card_pcsp_init(struct device *dev)
 		return err;
 	}
 
-#ifdef CONFIG_DEBUG_PAGEALLOC
 	/* Well, CONFIG_DEBUG_PAGEALLOC makes the sound horrible. Lets alert */
-	printk(KERN_WARNING "PCSP: CONFIG_DEBUG_PAGEALLOC is enabled, "
-	       "which may make the sound noisy.\n");
-#endif
+	if (debug_pagealloc_enabled()) {
+		printk(KERN_WARNING "PCSP: CONFIG_DEBUG_PAGEALLOC is enabled, "
+		       "which may make the sound noisy.\n");
+	}
 
 	return 0;
 }