[PATCH] Convert highest_possible_processor_id to nr_cpu_ids

We frequently need the maximum number of possible processors in order to
allocate arrays for all processors.  So far this was done using
highest_possible_processor_id().  However, we do need the number of
processors not the highest id.  Moreover the number was so far dynamically
calculated on each invokation.  The number of possible processors does not
change when the system is running.  We can therefore calculate that number
once.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Frederik Deweerdt <frederik.deweerdt@gmail.com>
Cc: Neil Brown <neilb@suse.de>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

5 files changed, 17 insertions, 29 deletions

diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h
index d0e8c8b0e34d..23f55140ccd5 100644
--- a/include/linux/cpumask.h
+++ b/include/linux/cpumask.h
@@ -398,11 +398,11 @@ extern cpumask_t cpu_present_map;
 #endif
 
 #ifdef CONFIG_SMP
-int highest_possible_processor_id(void);
+extern int nr_cpu_ids;
 #define any_online_cpu(mask) __any_online_cpu(&(mask))
 int __any_online_cpu(const cpumask_t *mask);
 #else
-#define highest_possible_processor_id() 0
+#define nr_cpu_ids                      1
 #define any_online_cpu(mask)            0
 #endif
 
diff --git a/init/main.c b/init/main.c
index 1c5f6dce1bd2..a92989e7836a 100644
--- a/init/main.c
+++ b/init/main.c
@@ -387,14 +387,19 @@ static void __init setup_per_cpu_areas(void)
 /* Called by boot processor to activate the rest. */
 static void __init smp_init(void)
 {
-        unsigned int i;
+        unsigned int cpu;
+        unsigned highest = 0;
+
+        for_each_cpu_mask(cpu, cpu_possible_map)
+                highest = cpu;
+        nr_cpu_ids = highest + 1;
 
         /* FIXME: This should be done in userspace --RR */
-        for_each_present_cpu(i) {
+        for_each_present_cpu(cpu) {
                 if (num_online_cpus() >= max_cpus)
                         break;
-                if (!cpu_online(i))
-                        cpu_up(i);
+                if (!cpu_online(cpu))
+                        cpu_up(cpu);
         }
 
         /* Any cleanup work */
diff --git a/lib/cpumask.c b/lib/cpumask.c
index 3a67dc5ada7d..1ea2c184315d 100644
--- a/lib/cpumask.c
+++ b/lib/cpumask.c
@@ -15,22 +15,8 @@ int __next_cpu(int n, const cpumask_t *srcp)
 }
 EXPORT_SYMBOL(__next_cpu);
 
-/*
- * Find the highest possible smp_processor_id()
- *
- * Note: if we're prepared to assume that cpu_possible_map never changes
- * (reasonable) then this function should cache its return value.
- */
-int highest_possible_processor_id(void)
-{
-        unsigned int cpu;
-        unsigned highest = 0;
-
-        for_each_cpu_mask(cpu, cpu_possible_map)
-                highest = cpu;
-        return highest;
-}
-EXPORT_SYMBOL(highest_possible_processor_id);
+int nr_cpu_ids;
+EXPORT_SYMBOL(nr_cpu_ids);
 
 int __any_online_cpu(const cpumask_t *mask)
 {
diff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c
index 34c49799f9b3..ac9984f98e59 100644
--- a/net/bridge/netfilter/ebtables.c
+++ b/net/bridge/netfilter/ebtables.c
@@ -833,8 +833,7 @@ static int translate_table(char *name, struct ebt_table_info *newinfo)
                 /* this will get free'd in do_replace()/ebt_register_table()
                    if an error occurs */
                 newinfo->chainstack =
-                        vmalloc((highest_possible_processor_id()+1)
-                                        * sizeof(*(newinfo->chainstack)));
+                        vmalloc(nr_cpu_ids * sizeof(*(newinfo->chainstack)));
                 if (!newinfo->chainstack)
                         return -ENOMEM;
                 for_each_possible_cpu(i) {
@@ -947,8 +946,7 @@ static int do_replace(void __user *user, unsigned int len)
         if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter))
                 return -ENOMEM;
 
-        countersize = COUNTER_OFFSET(tmp.nentries) *
-                                        (highest_possible_processor_id()+1);
+        countersize = COUNTER_OFFSET(tmp.nentries) * nr_cpu_ids;
         newinfo = vmalloc(sizeof(*newinfo) + countersize);
         if (!newinfo)
                 return -ENOMEM;
@@ -1168,8 +1166,7 @@ int ebt_register_table(struct ebt_table *table)
                 return -EINVAL;
         }
 
-        countersize = COUNTER_OFFSET(repl->nentries) *
-                                        (highest_possible_processor_id()+1);
+        countersize = COUNTER_OFFSET(repl->nentries) * nr_cpu_ids;
         newinfo = vmalloc(sizeof(*newinfo) + countersize);
         ret = -ENOMEM;
         if (!newinfo)
diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
index 232a99715ef2..8353829bc5c6 100644
--- a/net/sunrpc/svc.c
+++ b/net/sunrpc/svc.c
@@ -115,7 +115,7 @@ fail:
 static int
 svc_pool_map_init_percpu(struct svc_pool_map *m)
 {
-        unsigned int maxpools = highest_possible_processor_id() + 1;
+        unsigned int maxpools = nr_cpu_ids;
         unsigned int pidx = 0;
         unsigned int cpu;
         int err;