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author | Mateusz Nosek <mateusznosek0@gmail.com> | 2020-10-16 05:07:33 +0200 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-10-16 20:11:17 +0200 |
commit | 11c9c7edae06da789abfdeefe5123162a3f1c7dc (patch) | |
tree | 474756845a06f2a0414e3058db12706763722f73 /mm | |
parent | mm,hwpoison: try to narrow window race for free pages (diff) | |
download | linux-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.c | 20 |
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())); } |