sched: Separate out allocation/free/goto-hell from __build_sched_domains

Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20090818105300.GC29515@alberich.amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 99 insertions, 72 deletions

diff --git a/kernel/sched.c b/kernel/sched.c
index 565ff775fcda..c5d1fee42360 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -8107,6 +8107,23 @@ struct s_data {
         struct root_domain      *rd;
 };
 
+enum s_alloc {
+        sa_sched_groups = 0,
+        sa_rootdomain,
+        sa_tmpmask,
+        sa_send_covered,
+        sa_this_core_map,
+        sa_this_sibling_map,
+        sa_nodemask,
+        sa_sched_group_nodes,
+#ifdef CONFIG_NUMA
+        sa_notcovered,
+        sa_covered,
+        sa_domainspan,
+#endif
+        sa_none,
+};
+
 /*
  * SMT sched-domains:
  */
@@ -8394,6 +8411,77 @@ static void set_domain_attribute(struct sched_domain *sd,
         }
 }
 
+static void __free_domain_allocs(struct s_data *d, enum s_alloc what,
+                                 const struct cpumask *cpu_map)
+{
+        switch (what) {
+        case sa_sched_groups:
+                free_sched_groups(cpu_map, d->tmpmask); /* fall through */
+                d->sched_group_nodes = NULL;
+        case sa_rootdomain:
+                free_rootdomain(d->rd); /* fall through */
+        case sa_tmpmask:
+                free_cpumask_var(d->tmpmask); /* fall through */
+        case sa_send_covered:
+                free_cpumask_var(d->send_covered); /* fall through */
+        case sa_this_core_map:
+                free_cpumask_var(d->this_core_map); /* fall through */
+        case sa_this_sibling_map:
+                free_cpumask_var(d->this_sibling_map); /* fall through */
+        case sa_nodemask:
+                free_cpumask_var(d->nodemask); /* fall through */
+        case sa_sched_group_nodes:
+#ifdef CONFIG_NUMA
+                kfree(d->sched_group_nodes); /* fall through */
+        case sa_notcovered:
+                free_cpumask_var(d->notcovered); /* fall through */
+        case sa_covered:
+                free_cpumask_var(d->covered); /* fall through */
+        case sa_domainspan:
+                free_cpumask_var(d->domainspan); /* fall through */
+#endif
+        case sa_none:
+                break;
+        }
+}
+
+static enum s_alloc __visit_domain_allocation_hell(struct s_data *d,
+                                                   const struct cpumask *cpu_map)
+{
+#ifdef CONFIG_NUMA
+        if (!alloc_cpumask_var(&d->domainspan, GFP_KERNEL))
+                return sa_none;
+        if (!alloc_cpumask_var(&d->covered, GFP_KERNEL))
+                return sa_domainspan;
+        if (!alloc_cpumask_var(&d->notcovered, GFP_KERNEL))
+                return sa_covered;
+        /* Allocate the per-node list of sched groups */
+        d->sched_group_nodes = kcalloc(nr_node_ids,
+                                      sizeof(struct sched_group *), GFP_KERNEL);
+        if (!d->sched_group_nodes) {
+                printk(KERN_WARNING "Can not alloc sched group node list\n");
+                return sa_notcovered;
+        }
+        sched_group_nodes_bycpu[cpumask_first(cpu_map)] = d->sched_group_nodes;
+#endif
+        if (!alloc_cpumask_var(&d->nodemask, GFP_KERNEL))
+                return sa_sched_group_nodes;
+        if (!alloc_cpumask_var(&d->this_sibling_map, GFP_KERNEL))
+                return sa_nodemask;
+        if (!alloc_cpumask_var(&d->this_core_map, GFP_KERNEL))
+                return sa_this_sibling_map;
+        if (!alloc_cpumask_var(&d->send_covered, GFP_KERNEL))
+                return sa_this_core_map;
+        if (!alloc_cpumask_var(&d->tmpmask, GFP_KERNEL))
+                return sa_send_covered;
+        d->rd = alloc_rootdomain();
+        if (!d->rd) {
+                printk(KERN_WARNING "Cannot alloc root domain\n");
+                return sa_tmpmask;
+        }
+        return sa_rootdomain;
+}
+
 /*
  * Build sched domains for a given set of cpus and attach the sched domains
  * to the individual cpus
@@ -8401,50 +8489,17 @@ static void set_domain_attribute(struct sched_domain *sd,
 static int __build_sched_domains(const struct cpumask *cpu_map,
                                  struct sched_domain_attr *attr)
 {
+        enum s_alloc alloc_state = sa_none;
         struct s_data d;
-        int i, err = -ENOMEM;
+        int i;
 #ifdef CONFIG_NUMA
         d.sd_allnodes = 0;
-        if (!alloc_cpumask_var(&d.domainspan, GFP_KERNEL))
-                goto out;
-        if (!alloc_cpumask_var(&d.covered, GFP_KERNEL))
-                goto free_domainspan;
-        if (!alloc_cpumask_var(&d.notcovered, GFP_KERNEL))
-                goto free_covered;
-#endif
-
-        if (!alloc_cpumask_var(&d.nodemask, GFP_KERNEL))
-                goto free_notcovered;
-        if (!alloc_cpumask_var(&d.this_sibling_map, GFP_KERNEL))
-                goto free_nodemask;
-        if (!alloc_cpumask_var(&d.this_core_map, GFP_KERNEL))
-                goto free_this_sibling_map;
-        if (!alloc_cpumask_var(&d.send_covered, GFP_KERNEL))
-                goto free_this_core_map;
-        if (!alloc_cpumask_var(&d.tmpmask, GFP_KERNEL))
-                goto free_send_covered;
-
-#ifdef CONFIG_NUMA
-        /*
-         * Allocate the per-node list of sched groups
-         */
-        d.sched_group_nodes = kcalloc(nr_node_ids, sizeof(struct sched_group *),
-                                      GFP_KERNEL);
-        if (!d.sched_group_nodes) {
-                printk(KERN_WARNING "Can not alloc sched group node list\n");
-                goto free_tmpmask;
-        }
 #endif
 
-        d.rd = alloc_rootdomain();
-        if (!d.rd) {
-                printk(KERN_WARNING "Cannot alloc root domain\n");
-                goto free_sched_groups;
-        }
-
-#ifdef CONFIG_NUMA
-        sched_group_nodes_bycpu[cpumask_first(cpu_map)] = d.sched_group_nodes;
-#endif
+        alloc_state = __visit_domain_allocation_hell(&d, cpu_map);
+        if (alloc_state != sa_rootdomain)
+                goto error;
+        alloc_state = sa_sched_groups;
 
         /*
          * Set up domains for cpus specified by the cpu_map.
@@ -8675,41 +8730,13 @@ static int __build_sched_domains(const struct cpumask *cpu_map,
                 cpu_attach_domain(sd, d.rd, i);
         }
 
-        err = 0;
-
-free_tmpmask:
-        free_cpumask_var(d.tmpmask);
-free_send_covered:
-        free_cpumask_var(d.send_covered);
-free_this_core_map:
-        free_cpumask_var(d.this_core_map);
-free_this_sibling_map:
-        free_cpumask_var(d.this_sibling_map);
-free_nodemask:
-        free_cpumask_var(d.nodemask);
-free_notcovered:
-#ifdef CONFIG_NUMA
-        free_cpumask_var(d.notcovered);
-free_covered:
-        free_cpumask_var(d.covered);
-free_domainspan:
-        free_cpumask_var(d.domainspan);
-out:
-#endif
-        return err;
-
-free_sched_groups:
-#ifdef CONFIG_NUMA
-        kfree(d.sched_group_nodes);
-#endif
-        goto free_tmpmask;
+        d.sched_group_nodes = NULL; /* don't free this we still need it */
+        __free_domain_allocs(&d, sa_tmpmask, cpu_map);
+        return 0;
 
-#ifdef CONFIG_NUMA
 error:
-        free_sched_groups(cpu_map, d.tmpmask);
-        free_rootdomain(d.rd);
-        goto free_tmpmask;
-#endif
+        __free_domain_allocs(&d, alloc_state, cpu_map);
+        return -ENOMEM;
 }
 
 static int build_sched_domains(const struct cpumask *cpu_map)