sched/deadline: Replace NR_CPUS arrays

Tejun reported that his resume was failing due to order-3 allocations
from sched_domain building.

Replace the NR_CPUS arrays in there with a dynamically allocated
array.

Reported-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Juri Lelli <juri.lelli@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/n/tip-kat4gl1m5a6dwy6nzuqox45e@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/kernel/sched/cpudeadline.c b/kernel/sched/cpudeadline.c
index ab001b5d50487815da984947b592b26038cce794..bd95963dae80b92c34536d244de0986257e6490f 100644 (file)
--- a/kernel/sched/cpudeadline.c
+++ b/kernel/sched/cpudeadline.c
@@ -13,6 +13,7 @@
 
 #include <linux/gfp.h>
 #include <linux/kernel.h>
+#include <linux/slab.h>
 #include "cpudeadline.h"
 
 static inline int parent(int i)
@@ -39,8 +40,10 @@ static void cpudl_exchange(struct cpudl *cp, int a, int b)
 {
        int cpu_a = cp->elements[a].cpu, cpu_b = cp->elements[b].cpu;
 
-       swap(cp->elements[a], cp->elements[b]);
-       swap(cp->cpu_to_idx[cpu_a], cp->cpu_to_idx[cpu_b]);
+       swap(cp->elements[a].cpu, cp->elements[b].cpu);
+       swap(cp->elements[a].dl , cp->elements[b].dl );
+
+       swap(cp->elements[cpu_a].idx, cp->elements[cpu_b].idx);
 }
 
 static void cpudl_heapify(struct cpudl *cp, int idx)
@@ -140,7 +143,7 @@ void cpudl_set(struct cpudl *cp, int cpu, u64 dl, int is_valid)
        WARN_ON(!cpu_present(cpu));
 
        raw_spin_lock_irqsave(&cp->lock, flags);
-       old_idx = cp->cpu_to_idx[cpu];
+       old_idx = cp->elements[cpu].idx;
        if (!is_valid) {
                /* remove item */
                if (old_idx == IDX_INVALID) {
@@ -155,8 +158,8 @@ void cpudl_set(struct cpudl *cp, int cpu, u64 dl, int is_valid)
                cp->elements[old_idx].dl = cp->elements[cp->size - 1].dl;
                cp->elements[old_idx].cpu = new_cpu;
                cp->size--;
-               cp->cpu_to_idx[new_cpu] = old_idx;
-               cp->cpu_to_idx[cpu] = IDX_INVALID;
+               cp->elements[new_cpu].idx = old_idx;
+               cp->elements[cpu].idx = IDX_INVALID;
                while (old_idx > 0 && dl_time_before(
                                cp->elements[parent(old_idx)].dl,
                                cp->elements[old_idx].dl)) {
@@ -173,7 +176,7 @@ void cpudl_set(struct cpudl *cp, int cpu, u64 dl, int is_valid)
                cp->size++;
                cp->elements[cp->size - 1].dl = 0;
                cp->elements[cp->size - 1].cpu = cpu;
-               cp->cpu_to_idx[cpu] = cp->size - 1;
+               cp->elements[cpu].idx = cp->size - 1;
                cpudl_change_key(cp, cp->size - 1, dl);
                cpumask_clear_cpu(cpu, cp->free_cpus);
        } else {
@@ -195,10 +198,21 @@ int cpudl_init(struct cpudl *cp)
        memset(cp, 0, sizeof(*cp));
        raw_spin_lock_init(&cp->lock);
        cp->size = 0;
-       for (i = 0; i < NR_CPUS; i++)
-               cp->cpu_to_idx[i] = IDX_INVALID;
-       if (!alloc_cpumask_var(&cp->free_cpus, GFP_KERNEL))
+
+       cp->elements = kcalloc(nr_cpu_ids,
+                              sizeof(struct cpudl_item),
+                              GFP_KERNEL);
+       if (!cp->elements)
+               return -ENOMEM;
+
+       if (!alloc_cpumask_var(&cp->free_cpus, GFP_KERNEL)) {
+               kfree(cp->elements);
                return -ENOMEM;
+       }
+
+       for_each_possible_cpu(i)
+               cp->elements[i].idx = IDX_INVALID;
+
        cpumask_setall(cp->free_cpus);
 
        return 0;
@@ -211,4 +225,5 @@ int cpudl_init(struct cpudl *cp)
 void cpudl_cleanup(struct cpudl *cp)
 {
        free_cpumask_var(cp->free_cpus);
+       kfree(cp->elements);
 }

diff --git a/kernel/sched/cpudeadline.h b/kernel/sched/cpudeadline.h
index a202789a412c2131e22ae64a935505f913e26a72..538c9796ad4a0b085e4c4284683fe7856b420153 100644 (file)
--- a/kernel/sched/cpudeadline.h
+++ b/kernel/sched/cpudeadline.h
@@ -5,17 +5,17 @@
 
 #define IDX_INVALID     -1
 
-struct array_item {
+struct cpudl_item {
        u64 dl;
        int cpu;
+       int idx;
 };
 
 struct cpudl {
        raw_spinlock_t lock;
        int size;
-       int cpu_to_idx[NR_CPUS];
-       struct array_item elements[NR_CPUS];
        cpumask_var_t free_cpus;
+       struct cpudl_item *elements;
 };