sched: Simplify the free path some

If we check the root_domain reference count we can see if its been
used or not, use this observation to simplify some of the return
paths.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20110407122942.298339503@chello.nl
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 5 insertions, 6 deletions

diff --git a/kernel/sched.c b/kernel/sched.c
index 65204845063e..72c194c55c31 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -7023,7 +7023,8 @@ static void __free_domain_allocs(struct s_data *d, enum s_alloc what,
 
         switch (what) {
         case sa_rootdomain:
-                free_rootdomain(&d->rd->rcu); /* fall through */
+                if (!atomic_read(&d->rd->refcount))
+                        free_rootdomain(&d->rd->rcu); /* fall through */
         case sa_sd:
                 free_percpu(d->sd); /* fall through */
         case sa_sd_storage:
@@ -7208,7 +7209,7 @@ static int build_sched_domains(const struct cpumask *cpu_map,
         enum s_alloc alloc_state = sa_none;
         struct sched_domain *sd;
         struct s_data d;
-        int i;
+        int i, ret = -ENOMEM;
 
         alloc_state = __visit_domain_allocation_hell(&d, cpu_map);
         if (alloc_state != sa_rootdomain)
@@ -7261,12 +7262,10 @@ static int build_sched_domains(const struct cpumask *cpu_map,
         }
         rcu_read_unlock();
 
-        __free_domain_allocs(&d, sa_sd, cpu_map);
-        return 0;
-
+        ret = 0;
 error:
         __free_domain_allocs(&d, alloc_state, cpu_map);
-        return -ENOMEM;
+        return ret;
 }
 
 static cpumask_var_t *doms_cur; /* current sched domains */