[PATCH] vm_enough_memory microoptimisation

From: <ffrederick@prov-liege.be>

The expected case is (sysctl_overcommit_memory == 0), so put that first.

diff --git a/security/capability.c b/security/capability.c
index cff54dd440fc3aebc537be16e18bcbdb14ca1d2a..084d2c807fd4b71d653e61f5c06bb5fb512aeb44 100644 (file)
--- a/security/capability.c
+++ b/security/capability.c
@@ -295,12 +295,7 @@ int cap_vm_enough_memory(long pages)
 
        vm_acct_memory(pages);
 
-        /*
-        * Sometimes we want to use more memory than we have
-        */
-       if (sysctl_overcommit_memory == 1)
-               return 0;
-
+       /* We estimate memory ourselves (common case) */
        if (sysctl_overcommit_memory == 0) {
                free = get_page_cache_size();
                free += nr_free_pages();
@@ -322,10 +317,16 @@ int cap_vm_enough_memory(long pages)
 
                if (free > pages)
                        return 0;
+
                vm_unacct_memory(pages);
                return -ENOMEM;
        }
 
+       /* Kernel assumes allocation */
+       if (sysctl_overcommit_memory == 1)
+               return 0;
+
+       /* sysctl_overcommit_memory must be 2 which means strict_overcommit*/
        allowed = totalram_pages * sysctl_overcommit_ratio / 100;
        allowed += total_swap_pages;