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author | Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> | 2008-01-25 20:07:59 (GMT) |
---|---|---|
committer | Ingo Molnar <mingo@elte.hu> | 2008-01-25 20:07:59 (GMT) |
commit | ec2c507fe8c8fa3c04fc6cb99a382a965c477379 (patch) | |
tree | f139f738ba08576318ec09047148cdc7ae33ac9b /kernel/sched.c | |
parent | 93f992ccc008dd4030381caeebb252e85e66684b (diff) | |
download | linux-fsl-qoriq-ec2c507fe8c8fa3c04fc6cb99a382a965c477379.tar.xz |
sched: group scheduling, minor fixes
Minor bug fixes for the group scheduler:
- Use a mutex to serialize add/remove of task groups and also when
changing shares of a task group. Use the same mutex when printing
cfs_rq debugging stats for various task groups.
- Use list_for_each_entry_rcu in for_each_leaf_cfs_rq macro (when
walking task group list)
Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/sched.c')
-rw-r--r-- | kernel/sched.c | 33 |
1 files changed, 25 insertions, 8 deletions
diff --git a/kernel/sched.c b/kernel/sched.c index 7f827b7..cfa6958 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -169,8 +169,6 @@ struct task_group { /* runqueue "owned" by this group on each cpu */ struct cfs_rq **cfs_rq; unsigned long shares; - /* spinlock to serialize modification to shares */ - spinlock_t lock; struct rcu_head rcu; }; @@ -182,6 +180,11 @@ 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]; +/* task_group_mutex serializes add/remove of task groups and also changes to + * a task group's cpu shares. + */ +static DEFINE_MUTEX(task_group_mutex); + /* Default task group. * Every task in system belong to this group at bootup. */ @@ -221,9 +224,21 @@ static inline void set_task_cfs_rq(struct task_struct *p, unsigned int cpu) p->se.parent = task_group(p)->se[cpu]; } +static inline void lock_task_group_list(void) +{ + mutex_lock(&task_group_mutex); +} + +static inline void unlock_task_group_list(void) +{ + mutex_unlock(&task_group_mutex); +} + #else static inline void set_task_cfs_rq(struct task_struct *p, unsigned int cpu) { } +static inline void lock_task_group_list(void) { } +static inline void unlock_task_group_list(void) { } #endif /* CONFIG_FAIR_GROUP_SCHED */ @@ -6768,7 +6783,6 @@ void __init sched_init(void) se->parent = NULL; } init_task_group.shares = init_task_group_load; - spin_lock_init(&init_task_group.lock); #endif for (j = 0; j < CPU_LOAD_IDX_MAX; j++) @@ -7008,14 +7022,15 @@ struct task_group *sched_create_group(void) se->parent = NULL; } + tg->shares = NICE_0_LOAD; + + lock_task_group_list(); for_each_possible_cpu(i) { rq = cpu_rq(i); cfs_rq = tg->cfs_rq[i]; list_add_rcu(&cfs_rq->leaf_cfs_rq_list, &rq->leaf_cfs_rq_list); } - - tg->shares = NICE_0_LOAD; - spin_lock_init(&tg->lock); + unlock_task_group_list(); return tg; @@ -7061,10 +7076,12 @@ void sched_destroy_group(struct task_group *tg) struct cfs_rq *cfs_rq = NULL; int i; + lock_task_group_list(); for_each_possible_cpu(i) { cfs_rq = tg->cfs_rq[i]; list_del_rcu(&cfs_rq->leaf_cfs_rq_list); } + unlock_task_group_list(); BUG_ON(!cfs_rq); @@ -7146,7 +7163,7 @@ int sched_group_set_shares(struct task_group *tg, unsigned long shares) if (shares < 2) shares = 2; - spin_lock(&tg->lock); + lock_task_group_list(); if (tg->shares == shares) goto done; @@ -7155,7 +7172,7 @@ int sched_group_set_shares(struct task_group *tg, unsigned long shares) set_se_shares(tg->se[i], shares); done: - spin_unlock(&tg->lock); + unlock_task_group_list(); return 0; } |