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authorMateusz Nosek <mateusznosek0@gmail.com>2020-10-16 05:07:33 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2020-10-16 20:11:17 +0200
commit11c9c7edae06da789abfdeefe5123162a3f1c7dc (patch)
tree474756845a06f2a0414e3058db12706763722f73 /mm
parentmm,hwpoison: try to narrow window race for free pages (diff)
downloadlinux-11c9c7edae06da789abfdeefe5123162a3f1c7dc.tar.xz
linux-11c9c7edae06da789abfdeefe5123162a3f1c7dc.zip
mm/page_poison.c: replace bool variable with static key
Variable 'want_page_poisoning' is a switch deciding if page poisoning should be enabled. This patch changes it to be static key. Signed-off-by: Mateusz Nosek <mateusznosek0@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Oscar Salvador <OSalvador@suse.com> Link: https://lkml.kernel.org/r/20200921152931.938-1-mateusznosek0@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/page_poison.c20
1 files changed, 15 insertions, 5 deletions
diff --git a/mm/page_poison.c b/mm/page_poison.c
index 34b9181ee5d1..ae0482cded87 100644
--- a/mm/page_poison.c
+++ b/mm/page_poison.c
@@ -8,13 +8,23 @@
#include <linux/ratelimit.h>
#include <linux/kasan.h>
-static bool want_page_poisoning __read_mostly;
+static DEFINE_STATIC_KEY_FALSE_RO(want_page_poisoning);
static int __init early_page_poison_param(char *buf)
{
- if (!buf)
- return -EINVAL;
- return strtobool(buf, &want_page_poisoning);
+ int ret;
+ bool tmp;
+
+ ret = strtobool(buf, &tmp);
+ if (ret)
+ return ret;
+
+ if (tmp)
+ static_branch_enable(&want_page_poisoning);
+ else
+ static_branch_disable(&want_page_poisoning);
+
+ return 0;
}
early_param("page_poison", early_page_poison_param);
@@ -31,7 +41,7 @@ bool page_poisoning_enabled(void)
* Page poisoning is debug page alloc for some arches. If
* either of those options are enabled, enable poisoning.
*/
- return (want_page_poisoning ||
+ return (static_branch_unlikely(&want_page_poisoning) ||
(!IS_ENABLED(CONFIG_ARCH_SUPPORTS_DEBUG_PAGEALLOC) &&
debug_pagealloc_enabled()));
}