mm: factor commit limit calculation

The same calculation is currently done in three differents places.
Factor that code so future changes has to be made at only one place.

[akpm@linux-foundation.org: uninline vm_commit_limit()]
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Jerome Marchand
2013-11-12 15:08:31 -08:00
committed by Linus Torvalds
parent 715ea41e60
commit 00619bcc44
5 changed files with 18 additions and 9 deletions

View File

@@ -179,14 +179,12 @@ int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin)
goto error;
}
allowed = (totalram_pages - hugetlb_total_pages())
* sysctl_overcommit_ratio / 100;
allowed = vm_commit_limit();
/*
* Reserve some for root
*/
if (!cap_sys_admin)
allowed -= sysctl_admin_reserve_kbytes >> (PAGE_SHIFT - 10);
allowed += total_swap_pages;
/*
* Don't let a single process grow so big a user can't recover

View File

@@ -1948,13 +1948,12 @@ int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin)
goto error;
}
allowed = totalram_pages * sysctl_overcommit_ratio / 100;
allowed = vm_commit_limit();
/*
* Reserve some 3% for root
*/
if (!cap_sys_admin)
allowed -= sysctl_admin_reserve_kbytes >> (PAGE_SHIFT - 10);
allowed += total_swap_pages;
/*
* Don't let a single process grow so big a user can't recover

View File

@@ -7,6 +7,9 @@
#include <linux/security.h>
#include <linux/swap.h>
#include <linux/swapops.h>
#include <linux/mman.h>
#include <linux/hugetlb.h>
#include <asm/uaccess.h>
#include "internal.h"
@@ -398,6 +401,16 @@ struct address_space *page_mapping(struct page *page)
return mapping;
}
/*
* Committed memory limit enforced when OVERCOMMIT_NEVER policy is used
*/
unsigned long vm_commit_limit(void)
{
return ((totalram_pages - hugetlb_total_pages())
* sysctl_overcommit_ratio / 100) + total_swap_pages;
}
/* Tracepoints definitions. */
EXPORT_TRACEPOINT_SYMBOL(kmalloc);
EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc);