From: Hideo AOKI 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 Signed-off-by: Andrew Morton --- mm/mmap.c | 18 +++++++++++++++--- 1 files changed, 15 insertions(+), 3 deletions(-) diff -puN mm/mmap.c~overcommit-use-totalreserve_pages mm/mmap.c --- devel/mm/mmap.c~overcommit-use-totalreserve_pages 2006-04-05 20:24:06.000000000 -0700 +++ devel-akpm/mm/mmap.c 2006-04-05 20:24:06.000000000 -0700 @@ -121,14 +121,26 @@ int __vm_enough_memory(long pages, int c * 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 c */ if (atomic_read(&vm_committed_space) < (long)allowed) return 0; - +error: vm_unacct_memory(pages); return -ENOMEM; _