[PATCH] overcommit: use totalreserve_pages

This patch is an enhancement of OVERCOMMIT_GUESS algorithm in
__vm_enough_memory() in mm/mmap.c.

When the OVERCOMMIT_GUESS algorithm calculates the number of free pages,
the algorithm subtracts the number of reserved pages from the result
nr_free_pages().

Signed-off-by: Hideo Aoki <haoki@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Hideo AOKI 2006-04-10 22:53:00 -07:00 committed by Linus Torvalds
parent cb45b0e966
commit 6d9f783965

View file

@ -121,14 +121,26 @@ int __vm_enough_memory(long pages, int cap_sys_admin)
* only call if we're about to fail.
*/
n = nr_free_pages();
/*
* Leave reserved pages. The pages are not for anonymous pages.
*/
if (n <= totalreserve_pages)
goto error;
else
n -= totalreserve_pages;
/*
* Leave the last 3% for root
*/
if (!cap_sys_admin)
n -= n / 32;
free += n;
if (free > pages)
return 0;
vm_unacct_memory(pages);
return -ENOMEM;
goto error;
}
allowed = (totalram_pages - hugetlb_total_pages())
@ -150,7 +162,7 @@ int __vm_enough_memory(long pages, int cap_sys_admin)
*/
if (atomic_read(&vm_committed_space) < (long)allowed)
return 0;
error:
vm_unacct_memory(pages);
return -ENOMEM;