diff options
| -rw-r--r-- | kernel/sched/fair.c | 54 |
1 files changed, 35 insertions, 19 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 1422765d4b86..09aac90df89e 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -1052,6 +1052,20 @@ unlock: rcu_read_unlock(); } +static void task_numa_find_cpu(struct task_numa_env *env, long imp) +{ + int cpu; + + for_each_cpu(cpu, cpumask_of_node(env->dst_nid)) { + /* Skip this CPU if the source task cannot migrate */ + if (!cpumask_test_cpu(cpu, tsk_cpus_allowed(env->p))) + continue; + + env->dst_cpu = cpu; + task_numa_compare(env, imp); + } +} + static int task_numa_migrate(struct task_struct *p) { struct task_numa_env env = { @@ -1068,7 +1082,8 @@ static int task_numa_migrate(struct task_struct *p) }; struct sched_domain *sd; unsigned long faults; - int nid, cpu, ret; + int nid, ret; + long imp; /* * Pick the lowest SD_NUMA domain, as that would have the smallest @@ -1085,28 +1100,29 @@ static int task_numa_migrate(struct task_struct *p) faults = task_faults(p, env.src_nid); update_numa_stats(&env.src_stats, env.src_nid); + env.dst_nid = p->numa_preferred_nid; + imp = task_faults(env.p, env.dst_nid) - faults; + update_numa_stats(&env.dst_stats, env.dst_nid); - /* Find an alternative node with relatively better statistics */ - for_each_online_node(nid) { - long imp; - - if (nid == env.src_nid) - continue; - - /* Only consider nodes that recorded more faults */ - imp = task_faults(p, nid) - faults; - if (imp < 0) - continue; + /* + * If the preferred nid has capacity then use it. Otherwise find an + * alternative node with relatively better statistics. + */ + if (env.dst_stats.has_capacity) { + task_numa_find_cpu(&env, imp); + } else { + for_each_online_node(nid) { + if (nid == env.src_nid || nid == p->numa_preferred_nid) + continue; - env.dst_nid = nid; - update_numa_stats(&env.dst_stats, env.dst_nid); - for_each_cpu(cpu, cpumask_of_node(nid)) { - /* Skip this CPU if the source task cannot migrate */ - if (!cpumask_test_cpu(cpu, tsk_cpus_allowed(p))) + /* Only consider nodes that recorded more faults */ + imp = task_faults(env.p, nid) - faults; + if (imp < 0) continue; - env.dst_cpu = cpu; - task_numa_compare(&env, imp); + env.dst_nid = nid; + update_numa_stats(&env.dst_stats, env.dst_nid); + task_numa_find_cpu(&env, imp); } } |