tile: 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.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Takashi Iwai <tiwai@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/tile/mm/init.c

@@ -896,17 +896,15 @@ void __init pgtable_cache_init(void)
 		panic("pgtable_cache_init(): Cannot create pgd cache");
 }
 
-#ifdef CONFIG_DEBUG_PAGEALLOC
-static long __write_once initfree;
-#else
 static long __write_once initfree = 1;
-#endif
+static bool __write_once set_initfree_done;
 
 /* Select whether to free (1) or mark unusable (0) the __init pages. */
 static int __init set_initfree(char *str)
 {
 	long val;
 	if (kstrtol(str, 0, &val) == 0) {
+		set_initfree_done = true;
 		initfree = val;
 		pr_info("initfree: %s free init pages\n",
 			initfree ? "will" : "won't");
@@ -919,6 +917,11 @@ static void free_init_pages(char *what, unsigned long begin, unsigned long end)
 {
 	unsigned long addr = (unsigned long) begin;
 
+	/* Prefer user request first */
+	if (!set_initfree_done) {
+		if (debug_pagealloc_enabled())
+			initfree = 0;
+	}
 	if (kdata_huge && !initfree) {
 		pr_warn("Warning: ignoring initfree=0: incompatible with kdata=huge\n");
 		initfree = 1;