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sched: remove fixed NR_CPUS sized arrays in kernel_sched_c
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 * Change fixed size arrays to per_cpu variables or dynamically allocated
   arrays in sched_init() and sched_init_smp().

     (1) static struct sched_entity *init_sched_entity_p[NR_CPUS];
     (1) static struct cfs_rq *init_cfs_rq_p[NR_CPUS];
     (1) static struct sched_rt_entity *init_sched_rt_entity_p[NR_CPUS];
     (1) static struct rt_rq *init_rt_rq_p[NR_CPUS];
	 static struct sched_group **sched_group_nodes_bycpu[NR_CPUS];

     (1) - these arrays are allocated via alloc_bootmem_low()

 * Change sched_domain_debug_one() to use cpulist_scnprintf instead of
   cpumask_scnprintf.  This reduces the output buffer required and improves
   readability when large NR_CPU count machines arrive.

 * In sched_create_group() we allocate new arrays based on nr_cpu_ids.

Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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Mike Travis authored and Ingo Molnar committed Apr 19, 2008
1 parent d366f8c commit 434d53b
Showing 1 changed file with 52 additions and 28 deletions.
80 changes: 52 additions & 28 deletions kernel/sched.c
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Original file line number Diff line number Diff line change
Expand Up @@ -67,6 +67,7 @@
#include <linux/pagemap.h>
#include <linux/hrtimer.h>
#include <linux/tick.h>
#include <linux/bootmem.h>

#include <asm/tlb.h>
#include <asm/irq_regs.h>
Expand Down Expand Up @@ -276,17 +277,11 @@ struct task_group {
static DEFINE_PER_CPU(struct sched_entity, init_sched_entity);
/* Default task group's cfs_rq on each cpu */
static DEFINE_PER_CPU(struct cfs_rq, init_cfs_rq) ____cacheline_aligned_in_smp;

static struct sched_entity *init_sched_entity_p[NR_CPUS];
static struct cfs_rq *init_cfs_rq_p[NR_CPUS];
#endif

#ifdef CONFIG_RT_GROUP_SCHED
static DEFINE_PER_CPU(struct sched_rt_entity, init_sched_rt_entity);
static DEFINE_PER_CPU(struct rt_rq, init_rt_rq) ____cacheline_aligned_in_smp;

static struct sched_rt_entity *init_sched_rt_entity_p[NR_CPUS];
static struct rt_rq *init_rt_rq_p[NR_CPUS];
#endif

/* task_group_lock serializes add/remove of task groups and also changes to
Expand All @@ -310,17 +305,7 @@ static int init_task_group_load = INIT_TASK_GROUP_LOAD;
/* Default task group.
* Every task in system belong to this group at bootup.
*/
struct task_group init_task_group = {
#ifdef CONFIG_FAIR_GROUP_SCHED
.se = init_sched_entity_p,
.cfs_rq = init_cfs_rq_p,
#endif

#ifdef CONFIG_RT_GROUP_SCHED
.rt_se = init_sched_rt_entity_p,
.rt_rq = init_rt_rq_p,
#endif
};
struct task_group init_task_group;

/* return group to which a task belongs */
static inline struct task_group *task_group(struct task_struct *p)
Expand Down Expand Up @@ -3720,7 +3705,7 @@ static inline void trigger_load_balance(struct rq *rq, int cpu)
*/
int ilb = first_cpu(nohz.cpu_mask);

if (ilb != NR_CPUS)
if (ilb < nr_cpu_ids)
resched_cpu(ilb);
}
}
Expand Down Expand Up @@ -5671,11 +5656,11 @@ static void move_task_off_dead_cpu(int dead_cpu, struct task_struct *p)
dest_cpu = any_online_cpu(mask);

/* On any allowed CPU? */
if (dest_cpu == NR_CPUS)
if (dest_cpu >= nr_cpu_ids)
dest_cpu = any_online_cpu(p->cpus_allowed);

/* No more Mr. Nice Guy. */
if (dest_cpu == NR_CPUS) {
if (dest_cpu >= nr_cpu_ids) {
cpumask_t cpus_allowed = cpuset_cpus_allowed_locked(p);
/*
* Try to stay on the same cpuset, where the
Expand Down Expand Up @@ -6134,9 +6119,9 @@ static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level)
{
struct sched_group *group = sd->groups;
cpumask_t groupmask;
char str[NR_CPUS];
char str[256];

cpumask_scnprintf(str, NR_CPUS, sd->span);
cpulist_scnprintf(str, sizeof(str), sd->span);
cpus_clear(groupmask);

printk(KERN_DEBUG "%*s domain %d: ", level, "", level);
Expand Down Expand Up @@ -6189,7 +6174,7 @@ static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level)

cpus_or(groupmask, groupmask, group->cpumask);

cpumask_scnprintf(str, NR_CPUS, group->cpumask);
cpulist_scnprintf(str, sizeof(str), group->cpumask);
printk(KERN_CONT " %s", str);

group = group->next;
Expand Down Expand Up @@ -6601,7 +6586,7 @@ cpu_to_phys_group(int cpu, const cpumask_t *cpu_map, struct sched_group **sg)
* gets dynamically allocated.
*/
static DEFINE_PER_CPU(struct sched_domain, node_domains);
static struct sched_group **sched_group_nodes_bycpu[NR_CPUS];
static struct sched_group ***sched_group_nodes_bycpu;

static DEFINE_PER_CPU(struct sched_domain, allnodes_domains);
static DEFINE_PER_CPU(struct sched_group, sched_group_allnodes);
Expand Down Expand Up @@ -7244,6 +7229,11 @@ void __init sched_init_smp(void)
{
cpumask_t non_isolated_cpus;

#if defined(CONFIG_NUMA)
sched_group_nodes_bycpu = kzalloc(nr_cpu_ids * sizeof(void **),
GFP_KERNEL);
BUG_ON(sched_group_nodes_bycpu == NULL);
#endif
get_online_cpus();
arch_init_sched_domains(&cpu_online_map);
cpus_andnot(non_isolated_cpus, cpu_possible_map, cpu_isolated_map);
Expand All @@ -7261,6 +7251,11 @@ void __init sched_init_smp(void)
#else
void __init sched_init_smp(void)
{
#if defined(CONFIG_NUMA)
sched_group_nodes_bycpu = kzalloc(nr_cpu_ids * sizeof(void **),
GFP_KERNEL);
BUG_ON(sched_group_nodes_bycpu == NULL);
#endif
sched_init_granularity();
}
#endif /* CONFIG_SMP */
Expand Down Expand Up @@ -7358,6 +7353,35 @@ void __init sched_init(void)
{
int highest_cpu = 0;
int i, j;
unsigned long alloc_size = 0, ptr;

#ifdef CONFIG_FAIR_GROUP_SCHED
alloc_size += 2 * nr_cpu_ids * sizeof(void **);
#endif
#ifdef CONFIG_RT_GROUP_SCHED
alloc_size += 2 * nr_cpu_ids * sizeof(void **);
#endif
/*
* As sched_init() is called before page_alloc is setup,
* we use alloc_bootmem().
*/
if (alloc_size) {
ptr = (unsigned long)alloc_bootmem_low(alloc_size);

#ifdef CONFIG_FAIR_GROUP_SCHED
init_task_group.se = (struct sched_entity **)ptr;
ptr += nr_cpu_ids * sizeof(void **);

init_task_group.cfs_rq = (struct cfs_rq **)ptr;
ptr += nr_cpu_ids * sizeof(void **);
#endif
#ifdef CONFIG_RT_GROUP_SCHED
init_task_group.rt_se = (struct sched_rt_entity **)ptr;
ptr += nr_cpu_ids * sizeof(void **);

init_task_group.rt_rq = (struct rt_rq **)ptr;
#endif
}

#ifdef CONFIG_SMP
init_defrootdomain();
Expand Down Expand Up @@ -7610,10 +7634,10 @@ static int alloc_fair_sched_group(struct task_group *tg)
struct rq *rq;
int i;

tg->cfs_rq = kzalloc(sizeof(cfs_rq) * NR_CPUS, GFP_KERNEL);
tg->cfs_rq = kzalloc(sizeof(cfs_rq) * nr_cpu_ids, GFP_KERNEL);
if (!tg->cfs_rq)
goto err;
tg->se = kzalloc(sizeof(se) * NR_CPUS, GFP_KERNEL);
tg->se = kzalloc(sizeof(se) * nr_cpu_ids, GFP_KERNEL);
if (!tg->se)
goto err;

Expand Down Expand Up @@ -7695,10 +7719,10 @@ static int alloc_rt_sched_group(struct task_group *tg)
struct rq *rq;
int i;

tg->rt_rq = kzalloc(sizeof(rt_rq) * NR_CPUS, GFP_KERNEL);
tg->rt_rq = kzalloc(sizeof(rt_rq) * nr_cpu_ids, GFP_KERNEL);
if (!tg->rt_rq)
goto err;
tg->rt_se = kzalloc(sizeof(rt_se) * NR_CPUS, GFP_KERNEL);
tg->rt_se = kzalloc(sizeof(rt_se) * nr_cpu_ids, GFP_KERNEL);
if (!tg->rt_se)
goto err;

Expand Down

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