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>

diff --git a/fs/proc/meminfo.c b/fs/proc/meminfo.c
index 59d85d6..c805d5b 100644 (file)
--- a/fs/proc/meminfo.c
+++ b/fs/proc/meminfo.c
@@ -24,7 +24,6 @@ static int meminfo_proc_show(struct seq_file *m, void *v)
 {
        struct sysinfo i;
        unsigned long committed;
-       unsigned long allowed;
        struct vmalloc_info vmi;
        long cached;
        unsigned long pages[NR_LRU_LISTS];
@@ -37,8 +36,6 @@ static int meminfo_proc_show(struct seq_file *m, void *v)
        si_meminfo(&i);
        si_swapinfo(&i);
        committed = percpu_counter_read_positive(&vm_committed_as);
-       allowed = ((totalram_pages - hugetlb_total_pages())
-               * sysctl_overcommit_ratio / 100) + total_swap_pages;
 
        cached = global_page_state(NR_FILE_PAGES) -
                        total_swapcache_pages() - i.bufferram;
@@ -147,7 +144,7 @@ static int meminfo_proc_show(struct seq_file *m, void *v)
                K(global_page_state(NR_UNSTABLE_NFS)),
                K(global_page_state(NR_BOUNCE)),
                K(global_page_state(NR_WRITEBACK_TEMP)),
-               K(allowed),
+               K(vm_commit_limit()),
                K(committed),
                (unsigned long)VMALLOC_TOTAL >> 10,
                vmi.used >> 10,

diff --git a/include/linux/mman.h b/include/linux/mman.h
index 92dc257..7f7f8da 100644 (file)
--- a/include/linux/mman.h
+++ b/include/linux/mman.h
@@ -87,4 +87,6 @@ calc_vm_flag_bits(unsigned long flags)
               _calc_vm_trans(flags, MAP_DENYWRITE,  VM_DENYWRITE ) |
               _calc_vm_trans(flags, MAP_LOCKED,     VM_LOCKED    );
 }
+
+unsigned long vm_commit_limit(void);
 #endif /* _LINUX_MMAN_H */

diff --git a/mm/mmap.c b/mm/mmap.c
index 3d3e224..803048e 100644 (file)
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -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

diff --git a/mm/nommu.c b/mm/nommu.c
index ecd1f15..d8a957b 100644 (file)
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -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

diff --git a/mm/util.c b/mm/util.c
index eaf63fc..f7bc209 100644 (file)
--- a/mm/util.c
+++ b/mm/util.c
@@ -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);