The patch titled
Subject: mm/page_poison.c: replace bool variable with static key
has been added to the -mm tree. Its filename is
mm-page_poisonc-replace-bool-variable-with-static-key.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-page_poisonc-replace-bool-variable-with-static-key.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-page_poisonc-replace-bool-variable-with-static-key.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Mateusz Nosek <mateusznosek0@xxxxxxxxx>
Subject: 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.
Link: https://lkml.kernel.org/r/20200921152931.938-1-mateusznosek0@xxxxxxxxx
Signed-off-by: Mateusz Nosek <mateusznosek0@xxxxxxxxx>
Cc: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
Cc: Oscar Salvador <OSalvador@xxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/page_poison.c | 20 +++++++++++++++-----
1 file changed, 15 insertions(+), 5 deletions(-)
--- a/mm/page_poison.c~mm-page_poisonc-replace-bool-variable-with-static-key
+++ a/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()));
}
_
Patches currently in -mm which might be from mateusznosek0@xxxxxxxxx are
mm-slabc-clean-code-by-removing-redundant-if-condition.patch
mm-page_allocc-clean-code-by-removing-unnecessary-initialization.patch
mm-page_allocc-micro-optimization-remove-unnecessary-branch.patch
mm-page_allocc-fix-early-params-garbage-value-accesses.patch
mm-page_allocc-clean-code-by-merging-two-functions.patch
mmzone-clean-code-by-removing-unused-macro-parameter.patch
mm-compactionc-micro-optimization-remove-unnecessary-branch.patch
include-linux-compactionh-clean-code-by-removing-unused-enum-value.patch
mm-page_poisonc-replace-bool-variable-with-static-key.patch
