Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
  sched: move rq_weight data array out of .percpu
  percpu: allow pcpu_alloc() to be called with IRQs off

2 files changed, 28 insertions, 24 deletions

diff --git a/kernel/sched.c b/kernel/sched.c
index e88689522e66..a455dca884a6 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -1564,11 +1564,7 @@ static unsigned long cpu_avg_load_per_task(int cpu)
 
 #ifdef CONFIG_FAIR_GROUP_SCHED
 
-struct update_shares_data {
-	unsigned long rq_weight[NR_CPUS];
-};
-
-static DEFINE_PER_CPU(struct update_shares_data, update_shares_data);
+static __read_mostly unsigned long *update_shares_data;
 
 static void __set_se_shares(struct sched_entity *se, unsigned long shares);
 
@@ -1578,12 +1574,12 @@ static void __set_se_shares(struct sched_entity *se, unsigned long shares);
 static void update_group_shares_cpu(struct task_group *tg, int cpu,
 				    unsigned long sd_shares,
 				    unsigned long sd_rq_weight,
-				    struct update_shares_data *usd)
+				    unsigned long *usd_rq_weight)
 {
 	unsigned long shares, rq_weight;
 	int boost = 0;
 
-	rq_weight = usd->rq_weight[cpu];
+	rq_weight = usd_rq_weight[cpu];
 	if (!rq_weight) {
 		boost = 1;
 		rq_weight = NICE_0_LOAD;
@@ -1618,7 +1614,7 @@ static void update_group_shares_cpu(struct task_group *tg, int cpu,
 static int tg_shares_up(struct task_group *tg, void *data)
 {
 	unsigned long weight, rq_weight = 0, shares = 0;
-	struct update_shares_data *usd;
+	unsigned long *usd_rq_weight;
 	struct sched_domain *sd = data;
 	unsigned long flags;
 	int i;
@@ -1627,11 +1623,11 @@ static int tg_shares_up(struct task_group *tg, void *data)
 		return 0;
 
 	local_irq_save(flags);
-	usd = &__get_cpu_var(update_shares_data);
+	usd_rq_weight = per_cpu_ptr(update_shares_data, smp_processor_id());
 
 	for_each_cpu(i, sched_domain_span(sd)) {
 		weight = tg->cfs_rq[i]->load.weight;
-		usd->rq_weight[i] = weight;
+		usd_rq_weight[i] = weight;
 
 		/*
 		 * If there are currently no tasks on the cpu pretend there
@@ -1652,7 +1648,7 @@ static int tg_shares_up(struct task_group *tg, void *data)
 		shares = tg->shares;
 
 	for_each_cpu(i, sched_domain_span(sd))
-		update_group_shares_cpu(tg, i, shares, rq_weight, usd);
+		update_group_shares_cpu(tg, i, shares, rq_weight, usd_rq_weight);
 
 	local_irq_restore(flags);
 
@@ -9407,6 +9403,10 @@ void __init sched_init(void)
 #endif /* CONFIG_USER_SCHED */
 #endif /* CONFIG_GROUP_SCHED */
 
+#if defined CONFIG_FAIR_GROUP_SCHED && defined CONFIG_SMP
+	update_shares_data = __alloc_percpu(nr_cpu_ids * sizeof(unsigned long),
+					    __alignof__(unsigned long));
+#endif
 	for_each_possible_cpu(i) {
 		struct rq *rq;
 
diff --git a/mm/percpu.c b/mm/percpu.c
index 6af78c1ee704..d90797160c2a 100644
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -153,7 +153,10 @@ static int pcpu_reserved_chunk_limit;
  *
  * During allocation, pcpu_alloc_mutex is kept locked all the time and
  * pcpu_lock is grabbed and released as necessary.  All actual memory
- * allocations are done using GFP_KERNEL with pcpu_lock released.
+ * allocations are done using GFP_KERNEL with pcpu_lock released.  In
+ * general, percpu memory can't be allocated with irq off but
+ * irqsave/restore are still used in alloc path so that it can be used
+ * from early init path - sched_init() specifically.
  *
  * Free path accesses and alters only the index data structures, so it
  * can be safely called from atomic context.  When memory needs to be
@@ -366,7 +369,7 @@ static struct pcpu_chunk *pcpu_chunk_addr_search(void *addr)
  * RETURNS:
  * 0 if noop, 1 if successfully extended, -errno on failure.
  */
-static int pcpu_extend_area_map(struct pcpu_chunk *chunk)
+static int pcpu_extend_area_map(struct pcpu_chunk *chunk, unsigned long *flags)
 {
 	int new_alloc;
 	int *new;
@@ -376,7 +379,7 @@ static int pcpu_extend_area_map(struct pcpu_chunk *chunk)
 	if (chunk->map_alloc >= chunk->map_used + 2)
 		return 0;
 
-	spin_unlock_irq(&pcpu_lock);
+	spin_unlock_irqrestore(&pcpu_lock, *flags);
 
 	new_alloc = PCPU_DFL_MAP_ALLOC;
 	while (new_alloc < chunk->map_used + 2)
@@ -384,7 +387,7 @@ static int pcpu_extend_area_map(struct pcpu_chunk *chunk)
 
 	new = pcpu_mem_alloc(new_alloc * sizeof(new[0]));
 	if (!new) {
-		spin_lock_irq(&pcpu_lock);
+		spin_lock_irqsave(&pcpu_lock, *flags);
 		return -ENOMEM;
 	}
 
@@ -393,7 +396,7 @@ static int pcpu_extend_area_map(struct pcpu_chunk *chunk)
 	 * could have happened inbetween, so map_used couldn't have
 	 * grown.
 	 */
-	spin_lock_irq(&pcpu_lock);
+	spin_lock_irqsave(&pcpu_lock, *flags);
 	BUG_ON(new_alloc < chunk->map_used + 2);
 
 	size = chunk->map_alloc * sizeof(chunk->map[0]);
@@ -1047,6 +1050,7 @@ static void *pcpu_alloc(size_t size, size_t align, bool reserved)
 	struct pcpu_chunk *chunk;
 	const char *err;
 	int slot, off;
+	unsigned long flags;
 
 	if (unlikely(!size || size > PCPU_MIN_UNIT_SIZE || align > PAGE_SIZE)) {
 		WARN(true, "illegal size (%zu) or align (%zu) for "
@@ -1055,13 +1059,13 @@ static void *pcpu_alloc(size_t size, size_t align, bool reserved)
 	}
 
 	mutex_lock(&pcpu_alloc_mutex);
-	spin_lock_irq(&pcpu_lock);
+	spin_lock_irqsave(&pcpu_lock, flags);
 
 	/* serve reserved allocations from the reserved chunk if available */
 	if (reserved && pcpu_reserved_chunk) {
 		chunk = pcpu_reserved_chunk;
 		if (size > chunk->contig_hint ||
-		    pcpu_extend_area_map(chunk) < 0) {
+		    pcpu_extend_area_map(chunk, &flags) < 0) {
 			err = "failed to extend area map of reserved chunk";
 			goto fail_unlock;
 		}
@@ -1079,7 +1083,7 @@ restart:
 			if (size > chunk->contig_hint)
 				continue;
 
-			switch (pcpu_extend_area_map(chunk)) {
+			switch (pcpu_extend_area_map(chunk, &flags)) {
 			case 0:
 				break;
 			case 1:
@@ -1096,7 +1100,7 @@ restart:
 	}
 
 	/* hmmm... no space left, create a new chunk */
-	spin_unlock_irq(&pcpu_lock);
+	spin_unlock_irqrestore(&pcpu_lock, flags);
 
 	chunk = alloc_pcpu_chunk();
 	if (!chunk) {
@@ -1104,16 +1108,16 @@ restart:
 		goto fail_unlock_mutex;
 	}
 
-	spin_lock_irq(&pcpu_lock);
+	spin_lock_irqsave(&pcpu_lock, flags);
 	pcpu_chunk_relocate(chunk, -1);
 	goto restart;
 
 area_found:
-	spin_unlock_irq(&pcpu_lock);
+	spin_unlock_irqrestore(&pcpu_lock, flags);
 
 	/* populate, map and clear the area */
 	if (pcpu_populate_chunk(chunk, off, size)) {
-		spin_lock_irq(&pcpu_lock);
+		spin_lock_irqsave(&pcpu_lock, flags);
 		pcpu_free_area(chunk, off);
 		err = "failed to populate";
 		goto fail_unlock;
@@ -1125,7 +1129,7 @@ area_found:
 	return __addr_to_pcpu_ptr(chunk->base_addr + off);
 
 fail_unlock:
-	spin_unlock_irq(&pcpu_lock);
+	spin_unlock_irqrestore(&pcpu_lock, flags);
 fail_unlock_mutex:
 	mutex_unlock(&pcpu_alloc_mutex);
 	if (warn_limit) {