[PATCH] initialise total_memory() earlier

Initialise total_memory earlier in boot.  Because if for some reason we run
page reclaim early in boot, we don't want total_memory to be zero when we use
it as a divisor.

And rename total_memory to vm_total_pages to avoid naming clashes with
architectures.

Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Martin Bligh <mbligh@google.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 5 insertions, 6 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 5af33186a25f..71a0b2a23f5b 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1725,9 +1725,9 @@ void __meminit build_all_zonelists(void)
                 stop_machine_run(__build_all_zonelists, NULL, NR_CPUS);
                 /* cpuset refresh routine should be here */
         }
-
-        printk("Built %i zonelists\n", num_online_nodes());
-
+        vm_total_pages = nr_free_pagecache_pages();
+        printk("Built %i zonelists.  Total pages: %ld\n",
+                        num_online_nodes(), vm_total_pages);
 }
 
 /*
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 71a02e295037..72babac71dea 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -110,7 +110,7 @@ struct shrinker {
  * From 0 .. 100.  Higher means more swappy.
  */
 int vm_swappiness = 60;
-static long total_memory;
+long vm_total_pages;    /* The total number of pages which the VM controls */
 
 static LIST_HEAD(shrinker_list);
 static DECLARE_RWSEM(shrinker_rwsem);
@@ -743,7 +743,7 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
                  * how much memory
                  * is mapped.
                  */
-                mapped_ratio = (sc->nr_mapped * 100) / total_memory;
+                mapped_ratio = (sc->nr_mapped * 100) / vm_total_pages;
 
                 /*
                  * Now decide how much we really want to unmap some pages.  The
@@ -1482,7 +1482,6 @@ static int __init kswapd_init(void)
                 pgdat->kswapd = find_task_by_pid(pid);
                 read_unlock(&tasklist_lock);
         }
-        total_memory = nr_free_pagecache_pages();
         hotcpu_notifier(cpu_callback, 0);
         return 0;
 }