From 29d9df7d242254b34a2c5be25f76c13728a25621 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 20 Mar 2012 15:57:01 +0100 Subject: [PATCH] --- yaml --- r: 297413 b: refs/heads/master c: 2baab4e90495ebc9826c93f79d74d6e60a828d24 h: refs/heads/master i: 297411: 374505143bf2fd98ea315beb7dbd19ef9fc38306 v: v3 --- [refs] | 2 +- trunk/include/linux/cpuset.h | 6 ++-- trunk/kernel/cpuset.c | 20 +++--------- trunk/kernel/sched/core.c | 62 ++++++++++++++++++++++++++---------- 4 files changed, 53 insertions(+), 37 deletions(-) diff --git a/[refs] b/[refs] index 0558e685bf7e..20d66a60221d 100644 --- a/[refs] +++ b/[refs] @@ -1,2 +1,2 @@ --- -refs/heads/master: bc758133ed73d4b06952bec21da23e28e62bf3ba +refs/heads/master: 2baab4e90495ebc9826c93f79d74d6e60a828d24 diff --git a/trunk/include/linux/cpuset.h b/trunk/include/linux/cpuset.h index e9eaec522655..e0ffaf061ab7 100644 --- a/trunk/include/linux/cpuset.h +++ b/trunk/include/linux/cpuset.h @@ -22,7 +22,7 @@ extern int cpuset_init(void); extern void cpuset_init_smp(void); extern void cpuset_update_active_cpus(void); extern void cpuset_cpus_allowed(struct task_struct *p, struct cpumask *mask); -extern int cpuset_cpus_allowed_fallback(struct task_struct *p); +extern void cpuset_cpus_allowed_fallback(struct task_struct *p); extern nodemask_t cpuset_mems_allowed(struct task_struct *p); #define cpuset_current_mems_allowed (current->mems_allowed) void cpuset_init_current_mems_allowed(void); @@ -144,10 +144,8 @@ static inline void cpuset_cpus_allowed(struct task_struct *p, cpumask_copy(mask, cpu_possible_mask); } -static inline int cpuset_cpus_allowed_fallback(struct task_struct *p) +static inline void cpuset_cpus_allowed_fallback(struct task_struct *p) { - do_set_cpus_allowed(p, cpu_possible_mask); - return cpumask_any(cpu_active_mask); } static inline nodemask_t cpuset_mems_allowed(struct task_struct *p) diff --git a/trunk/kernel/cpuset.c b/trunk/kernel/cpuset.c index a09ac2b9a661..c9837b74ab96 100644 --- a/trunk/kernel/cpuset.c +++ b/trunk/kernel/cpuset.c @@ -2195,7 +2195,7 @@ void cpuset_cpus_allowed(struct task_struct *tsk, struct cpumask *pmask) mutex_unlock(&callback_mutex); } -int cpuset_cpus_allowed_fallback(struct task_struct *tsk) +void cpuset_cpus_allowed_fallback(struct task_struct *tsk) { const struct cpuset *cs; int cpu; @@ -2219,22 +2219,10 @@ int cpuset_cpus_allowed_fallback(struct task_struct *tsk) * changes in tsk_cs()->cpus_allowed. Otherwise we can temporary * set any mask even if it is not right from task_cs() pov, * the pending set_cpus_allowed_ptr() will fix things. + * + * select_fallback_rq() will fix things ups and set cpu_possible_mask + * if required. */ - - cpu = cpumask_any_and(&tsk->cpus_allowed, cpu_active_mask); - if (cpu >= nr_cpu_ids) { - /* - * Either tsk->cpus_allowed is wrong (see above) or it - * is actually empty. The latter case is only possible - * if we are racing with remove_tasks_in_empty_cpuset(). - * Like above we can temporary set any mask and rely on - * set_cpus_allowed_ptr() as synchronization point. - */ - do_set_cpus_allowed(tsk, cpu_possible_mask); - cpu = cpumask_any(cpu_active_mask); - } - - return cpu; } void cpuset_init_current_mems_allowed(void) diff --git a/trunk/kernel/sched/core.c b/trunk/kernel/sched/core.c index e3ccc13c4caa..9c1629c90b2d 100644 --- a/trunk/kernel/sched/core.c +++ b/trunk/kernel/sched/core.c @@ -1263,29 +1263,59 @@ EXPORT_SYMBOL_GPL(kick_process); */ static int select_fallback_rq(int cpu, struct task_struct *p) { - int dest_cpu; const struct cpumask *nodemask = cpumask_of_node(cpu_to_node(cpu)); + enum { cpuset, possible, fail } state = cpuset; + int dest_cpu; /* Look for allowed, online CPU in same node. */ - for_each_cpu_and(dest_cpu, nodemask, cpu_active_mask) + for_each_cpu_mask(dest_cpu, *nodemask) { + if (!cpu_online(dest_cpu)) + continue; + if (!cpu_active(dest_cpu)) + continue; if (cpumask_test_cpu(dest_cpu, tsk_cpus_allowed(p))) return dest_cpu; + } - /* Any allowed, online CPU? */ - dest_cpu = cpumask_any_and(tsk_cpus_allowed(p), cpu_active_mask); - if (dest_cpu < nr_cpu_ids) - return dest_cpu; + for (;;) { + /* Any allowed, online CPU? */ + for_each_cpu_mask(dest_cpu, *tsk_cpus_allowed(p)) { + if (!cpu_online(dest_cpu)) + continue; + if (!cpu_active(dest_cpu)) + continue; + goto out; + } - /* No more Mr. Nice Guy. */ - dest_cpu = cpuset_cpus_allowed_fallback(p); - /* - * Don't tell them about moving exiting tasks or - * kernel threads (both mm NULL), since they never - * leave kernel. - */ - if (p->mm && printk_ratelimit()) { - printk_sched("process %d (%s) no longer affine to cpu%d\n", - task_pid_nr(p), p->comm, cpu); + switch (state) { + case cpuset: + /* No more Mr. Nice Guy. */ + cpuset_cpus_allowed_fallback(p); + state = possible; + break; + + case possible: + do_set_cpus_allowed(p, cpu_possible_mask); + state = fail; + break; + + case fail: + BUG(); + break; + } + } + +out: + if (state != cpuset) { + /* + * Don't tell them about moving exiting tasks or + * kernel threads (both mm NULL), since they never + * leave kernel. + */ + if (p->mm && printk_ratelimit()) { + printk_sched("process %d (%s) no longer affine to cpu%d\n", + task_pid_nr(p), p->comm, cpu); + } } return dest_cpu;