diff options
| author | Andrew Morton <akpm@osdl.org> | 2004-02-03 18:49:05 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@home.osdl.org> | 2004-02-03 18:49:05 -0800 |
| commit | c7f6fcf55b7ce3cf61e0953a18e0ab9e70421a47 (patch) | |
| tree | 6b3390d0a61f5614ac6f54eab1c388c9422db557 /security | |
| parent | a9b9b3c5ebb3f8d4814c10baf7176fd8711d063f (diff) | |
| download | history-c7f6fcf55b7ce3cf61e0953a18e0ab9e70421a47.tar.gz | |
[PATCH] rate limit nr_free_pages
From: Jes Sorensen <jes@trained-monkey.org>
nr_free_pages() is expensive, especially on large SMP machines. The patch
changes the memory overcommit code so that it only calls nr_free_pages() is
we're about to fail the allocation attempt.
Diffstat (limited to 'security')
| -rw-r--r-- | security/commoncap.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/security/commoncap.c b/security/commoncap.c index 355533d68b9145..f80b1a17bbe4b5 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -321,8 +321,9 @@ int cap_vm_enough_memory(long pages) return 0; if (sysctl_overcommit_memory == 0) { + unsigned long n; + free = get_page_cache_size(); - free += nr_free_pages(); free += nr_swap_pages; /* @@ -341,6 +342,18 @@ int cap_vm_enough_memory(long pages) if (free > pages) return 0; + + /* + * nr_free_pages() is very expensive on large systems, + * only call if we're about to fail. + */ + n = nr_free_pages(); + if (!capable(CAP_SYS_ADMIN)) + n -= n / 32; + free += n; + + if (free > pages) + return 0; vm_unacct_memory(pages); return -ENOMEM; } |