A-Team_Digital_Solutions/android_kernel_motorola_sm6375
Watch
2
0
Fork
You've already forked android_kernel_motorola_sm6375
 0
mirror of https://github.com/BobTheBlinker/android_kernel_motorola_sm6375.git synced 2026-10-28 18:51:56 -04:00
Code Issues Projects Releases Packages Wiki Activity

mm: replace hardcoded 3% with admin_reserve_pages knob

Browse source 
Add an admin_reserve_kbytes knob to allow admins to change the hardcoded
memory reserve to something other than 3%, which may be multiple
gigabytes on large memory systems.  Only about 8MB is necessary to
enable recovery in the default mode, and only a few hundred MB are
required even when overcommit is disabled.

This affects OVERCOMMIT_GUESS and OVERCOMMIT_NEVER.

admin_reserve_kbytes is initialized to min(3% free pages, 8MB)

I arrived at 8MB by summing the RSS of sshd or login, bash, and top.

Please see first patch in this series for full background, motivation,
testing, and full changelog.

[[email protected]: coding-style fixes]
[[email protected]: make init_admin_reserve() static]
Signed-off-by: Andrew Shewmaker <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
This commit is contained in:
Andrew Shewmaker 2013-04-29 15:08:11 -07:00 • committed by Linus Torvalds
commit 4eeab4f558
5 changed files with 90 additions and 8 deletions
Download patch file Download diff file Expand all files Collapse all files

30
mm/mmap.c
View file

@ -85,6 +85,7 @@ int sysctl_overcommit_memory __read_mostly = OVERCOMMIT_GUESS; /* heuristic ove
int sysctl_overcommit_ratio __read_mostly = 50; /* default is 50% */
int sysctl_max_map_count __read_mostly = DEFAULT_MAX_MAP_COUNT;
unsigned long sysctl_user_reserve_kbytes __read_mostly = 1UL << 17; /* 128MB */
unsigned long sysctl_admin_reserve_kbytes __read_mostly = 1UL << 13; /* 8MB */
/*
* Make sure vm_committed_as in one cacheline and not cacheline shared with
* other variables. It can be updated by several CPUs frequently.
@ -164,10 +165,10 @@ int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin)
free -= totalreserve_pages;
/*
* Leave the last 3% for root
* Reserve some for root
*/
if (!cap_sys_admin)
free -= free / 32;
free -= sysctl_admin_reserve_kbytes >> (PAGE_SHIFT - 10);
if (free > pages)
return 0;
@ -178,10 +179,10 @@ int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin)
allowed = (totalram_pages - hugetlb_total_pages())
* sysctl_overcommit_ratio / 100;
/*
* Leave the last 3% for root
* Reserve some for root
*/
if (!cap_sys_admin)
allowed -= allowed / 32;
allowed -= sysctl_admin_reserve_kbytes >> (PAGE_SHIFT - 10);
allowed += total_swap_pages;
/*
@ -3119,3 +3120,24 @@ static int __meminit init_user_reserve(void)
return 0;
}
module_init(init_user_reserve)
/*
* Initialise sysctl_admin_reserve_kbytes.
*
* The purpose of sysctl_admin_reserve_kbytes is to allow the sys admin
* to log in and kill a memory hogging process.
*
* Systems with more than 256MB will reserve 8MB, enough to recover
* with sshd, bash, and top in OVERCOMMIT_GUESS. Smaller systems will
* only reserve 3% of free pages by default.
*/
static int __meminit init_admin_reserve(void)
{
unsigned long free_kbytes;
free_kbytes = global_page_state(NR_FREE_PAGES) << (PAGE_SHIFT - 10);
sysctl_admin_reserve_kbytes = min(free_kbytes / 32, 1UL << 13);
return 0;
}
module_init(init_admin_reserve)

30
mm/nommu.c
View file

@ -64,6 +64,7 @@ int sysctl_overcommit_ratio = 50; /* default is 50% */
int sysctl_max_map_count = DEFAULT_MAX_MAP_COUNT;
int sysctl_nr_trim_pages = CONFIG_NOMMU_INITIAL_TRIM_EXCESS;
unsigned long sysctl_user_reserve_kbytes __read_mostly = 1UL << 17; /* 128MB */
unsigned long sysctl_admin_reserve_kbytes __read_mostly = 1UL << 13; /* 8MB */
int heap_stack_gap = 0;
atomic_long_t mmap_pages_allocated;
@ -1939,10 +1940,10 @@ int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin)
free -= totalreserve_pages;
/*
* Leave the last 3% for root
* Reserve some for root
*/
if (!cap_sys_admin)
free -= free / 32;
free -= sysctl_admin_reserve_kbytes >> (PAGE_SHIFT - 10);
if (free > pages)
return 0;
@ -1952,10 +1953,10 @@ int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin)
allowed = totalram_pages * sysctl_overcommit_ratio / 100;
/*
* Leave the last 3% for root
* Reserve some 3% for root
*/
if (!cap_sys_admin)
allowed -= allowed / 32;
allowed -= sysctl_admin_reserve_kbytes >> (PAGE_SHIFT - 10);
allowed += total_swap_pages;
/*
@ -2147,3 +2148,24 @@ static int __meminit init_user_reserve(void)
return 0;
}
module_init(init_user_reserve)
/*
* Initialise sysctl_admin_reserve_kbytes.
*
* The purpose of sysctl_admin_reserve_kbytes is to allow the sys admin
* to log in and kill a memory hogging process.
*
* Systems with more than 256MB will reserve 8MB, enough to recover
* with sshd, bash, and top in OVERCOMMIT_GUESS. Smaller systems will
* only reserve 3% of free pages by default.
*/
static int __meminit init_admin_reserve(void)
{
unsigned long free_kbytes;
free_kbytes = global_page_state(NR_FREE_PAGES) << (PAGE_SHIFT - 10);
sysctl_admin_reserve_kbytes = min(free_kbytes / 32, 1UL << 13);
return 0;
}
module_init(init_admin_reserve)