sched: convert struct cpupri_vec cpumask_var_t.

Impact: stack usage reduction, (future) size reduction for large NR_CPUS.

Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves
space for small nr_cpu_ids but big CONFIG_NR_CPUS.

The fact cpupro_init is called both before and after the slab is
available makes for an ugly parameter unfortunately.

We also use cpumask_any_and to get rid of a temporary in cpupri_find.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 7 insertions, 2 deletions

diff --git a/kernel/sched.c b/kernel/sched.c
index 42588ad93b25..94fa333c1e7c 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -6792,6 +6792,8 @@ sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent)
 
 static void free_rootdomain(struct root_domain *rd)
 {
+        cpupri_cleanup(&rd->cpupri);
+
         free_cpumask_var(rd->rto_mask);
         free_cpumask_var(rd->online);
         free_cpumask_var(rd->span);
@@ -6834,7 +6836,7 @@ static int init_rootdomain(struct root_domain *rd, bool bootmem)
                 alloc_bootmem_cpumask_var(&def_root_domain.span);
                 alloc_bootmem_cpumask_var(&def_root_domain.online);
                 alloc_bootmem_cpumask_var(&def_root_domain.rto_mask);
-                cpupri_init(&rd->cpupri);
+                cpupri_init(&rd->cpupri, true);
                 return 0;
         }
 
@@ -6845,9 +6847,12 @@ static int init_rootdomain(struct root_domain *rd, bool bootmem)
         if (!alloc_cpumask_var(&rd->rto_mask, GFP_KERNEL))
                 goto free_online;
 
-        cpupri_init(&rd->cpupri);
+        if (cpupri_init(&rd->cpupri, false) != 0)
+                goto free_rto_mask;
         return 0;
 
+free_rto_mask:
+        free_cpumask_var(rd->rto_mask);
 free_online:
         free_cpumask_var(rd->online);
 free_span: