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) {