2020-12-10 10:17:04

by Fengfei Xi

Subject: [PATCH] docs: admin-guide: Fix default value of max_map_count in sysctl/vm.rst

Since the default value of sysctl_max_map_count is defined as
DEFAULT_MAX_MAP_COUNT from mm/util.c

int sysctl_max_map_count __read_mostly = DEFAULT_MAX_MAP_COUNT;

DEFAULT_MAX_MAP_COUNT is defined as 65530 (65535-5) in include/linux/mm.h

#define MAPCOUNT_ELF_CORE_MARGIN (5)
#define DEFAULT_MAX_MAP_COUNT (USHRT_MAX - MAPCOUNT_ELF_CORE_MARGIN)

Signed-off-by: Fengfei Xi <[email protected]>
---
Documentation/admin-guide/sysctl/vm.rst | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Documentation/admin-guide/sysctl/vm.rst b/Documentation/admin-guide/sysctl/vm.rst
index f455fa00c..834c3fc74 100644
--- a/Documentation/admin-guide/sysctl/vm.rst
+++ b/Documentation/admin-guide/sysctl/vm.rst
@@ -428,7 +428,7 @@ While most applications need less than a thousand maps, certain
programs, particularly malloc debuggers, may consume lots of them,
e.g., up to one or two maps per allocation.

-The default value is 65536.
+The default value is 65530.


memory_failure_early_kill:
--
2.17.1

2020-12-21 17:02:10

by Jonathan Corbet

Subject: Re: [PATCH] docs: admin-guide: Fix default value of max_map_count in sysctl/vm.rst

On Thu, 10 Dec 2020 16:21:34 +0800
Fengfei Xi <[email protected]> wrote:

> Since the default value of sysctl_max_map_count is defined as
> DEFAULT_MAX_MAP_COUNT from mm/util.c
>
> int sysctl_max_map_count __read_mostly = DEFAULT_MAX_MAP_COUNT;
>
> DEFAULT_MAX_MAP_COUNT is defined as 65530 (65535-5) in include/linux/mm.h
>
> #define MAPCOUNT_ELF_CORE_MARGIN (5)
> #define DEFAULT_MAX_MAP_COUNT (USHRT_MAX - MAPCOUNT_ELF_CORE_MARGIN)
>
> Signed-off-by: Fengfei Xi <[email protected]>
> ---
> Documentation/admin-guide/sysctl/vm.rst | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/Documentation/admin-guide/sysctl/vm.rst b/Documentation/admin-guide/sysctl/vm.rst
> index f455fa00c..834c3fc74 100644
> --- a/Documentation/admin-guide/sysctl/vm.rst
> +++ b/Documentation/admin-guide/sysctl/vm.rst
> @@ -428,7 +428,7 @@ While most applications need less than a thousand maps, certain
> programs, particularly malloc debuggers, may consume lots of them,
> e.g., up to one or two maps per allocation.
>
> -The default value is 65536.
> +The default value is 65530.

Applied, thanks.

jon