sched: No need for bootmem special cases

As of commit dcce284 ("mm: Extend gfp masking to the page
allocator") and commit 7e85ee0 ("slab,slub: don't enable
interrupts during early boot"), the slab allocator makes
sure we don't attempt to sleep during boot.

Therefore, remove bootmem special cases from the scheduler
and use plain GFP_KERNEL instead.

Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1279225102-2572-1-git-send-email-penberg@cs.helsinki.fi>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

kernel/sched.c

@@ -6248,23 +6248,18 @@ static void rq_attach_root(struct rq *rq, struct root_domain *rd)
 		free_rootdomain(old_rd);
 }
 
-static int init_rootdomain(struct root_domain *rd, bool bootmem)
+static int init_rootdomain(struct root_domain *rd)
 {
-	gfp_t gfp = GFP_KERNEL;
-
 	memset(rd, 0, sizeof(*rd));
 
-	if (bootmem)
-		gfp = GFP_NOWAIT;
-
-	if (!alloc_cpumask_var(&rd->span, gfp))
+	if (!alloc_cpumask_var(&rd->span, GFP_KERNEL))
 		goto out;
-	if (!alloc_cpumask_var(&rd->online, gfp))
+	if (!alloc_cpumask_var(&rd->online, GFP_KERNEL))
 		goto free_span;
-	if (!alloc_cpumask_var(&rd->rto_mask, gfp))
+	if (!alloc_cpumask_var(&rd->rto_mask, GFP_KERNEL))
 		goto free_online;
 
-	if (cpupri_init(&rd->cpupri, bootmem) != 0)
+	if (cpupri_init(&rd->cpupri) != 0)
 		goto free_rto_mask;
 	return 0;
 
@@ -6280,7 +6275,7 @@ static int init_rootdomain(struct root_domain *rd, bool bootmem)
 
 static void init_defrootdomain(void)
 {
-	init_rootdomain(&def_root_domain, true);
+	init_rootdomain(&def_root_domain);
 
 	atomic_set(&def_root_domain.refcount, 1);
 }
@@ -6293,7 +6288,7 @@ static struct root_domain *alloc_rootdomain(void)
 	if (!rd)
 		return NULL;
 
-	if (init_rootdomain(rd, false) != 0) {
+	if (init_rootdomain(rd) != 0) {
 		kfree(rd);
 		return NULL;
 	}

kernel/sched_cpupri.c

@@ -166,22 +166,18 @@ void cpupri_set(struct cpupri *cp, int cpu, int newpri)
  *
  * Returns: -ENOMEM if memory fails.
  */
-int cpupri_init(struct cpupri *cp, bool bootmem)
+int cpupri_init(struct cpupri *cp)
 {
-	gfp_t gfp = GFP_KERNEL;
 	int i;
 
-	if (bootmem)
-		gfp = GFP_NOWAIT;
-
 	memset(cp, 0, sizeof(*cp));
 
 	for (i = 0; i < CPUPRI_NR_PRIORITIES; i++) {
 		struct cpupri_vec *vec = &cp->pri_to_cpu[i];
 
 		raw_spin_lock_init(&vec->lock);
 		vec->count = 0;
-		if (!zalloc_cpumask_var(&vec->mask, gfp))
+		if (!zalloc_cpumask_var(&vec->mask, GFP_KERNEL))
 			goto cleanup;
 	}
 

kernel/sched_cpupri.h

@@ -27,7 +27,7 @@ struct cpupri {
 int  cpupri_find(struct cpupri *cp,
 		 struct task_struct *p, struct cpumask *lowest_mask);
 void cpupri_set(struct cpupri *cp, int cpu, int pri);
-int cpupri_init(struct cpupri *cp, bool bootmem);
+int cpupri_init(struct cpupri *cp);
 void cpupri_cleanup(struct cpupri *cp);
 #else
 #define cpupri_set(cp, cpu, pri) do { } while (0)