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author | 2010-05-07 11:30:29 +0200 | |
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committer | 2010-05-07 11:30:30 +0200 | |
commit | cce913178118b0b36742eb7544c2b38a0c957ee7 (patch) | |
tree | 25a6d7b4e01fea2932e6e2962a75f7a3d8c19a4f /kernel/sched.c | |
parent | perf: Fix check at end of event search (diff) | |
parent | perf: Fix exit() vs PERF_FORMAT_GROUP (diff) | |
download | linux-cce913178118b0b36742eb7544c2b38a0c957ee7.tar.gz linux-cce913178118b0b36742eb7544c2b38a0c957ee7.tar.bz2 linux-cce913178118b0b36742eb7544c2b38a0c957ee7.zip |
Merge branch 'perf/urgent' into perf/core
Merge reason: Resolve patch dependency
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/sched.c')
-rw-r--r-- | kernel/sched.c | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/kernel/sched.c b/kernel/sched.c index b0bbadc24955..b11b80a3eed3 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -323,6 +323,15 @@ static inline struct task_group *task_group(struct task_struct *p) /* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */ static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { + /* + * Strictly speaking this rcu_read_lock() is not needed since the + * task_group is tied to the cgroup, which in turn can never go away + * as long as there are tasks attached to it. + * + * However since task_group() uses task_subsys_state() which is an + * rcu_dereference() user, this quiets CONFIG_PROVE_RCU. + */ + rcu_read_lock(); #ifdef CONFIG_FAIR_GROUP_SCHED p->se.cfs_rq = task_group(p)->cfs_rq[cpu]; p->se.parent = task_group(p)->se[cpu]; @@ -332,6 +341,7 @@ static inline void set_task_rq(struct task_struct *p, unsigned int cpu) p->rt.rt_rq = task_group(p)->rt_rq[cpu]; p->rt.parent = task_group(p)->rt_se[cpu]; #endif + rcu_read_unlock(); } #else @@ -3737,7 +3747,7 @@ int mutex_spin_on_owner(struct mutex *lock, struct thread_info *owner) * the mutex owner just released it and exited. */ if (probe_kernel_address(&owner->cpu, cpu)) - goto out; + return 0; #else cpu = owner->cpu; #endif @@ -3747,14 +3757,14 @@ int mutex_spin_on_owner(struct mutex *lock, struct thread_info *owner) * the cpu field may no longer be valid. */ if (cpu >= nr_cpumask_bits) - goto out; + return 0; /* * We need to validate that we can do a * get_cpu() and that we have the percpu area. */ if (!cpu_online(cpu)) - goto out; + return 0; rq = cpu_rq(cpu); @@ -3773,7 +3783,7 @@ int mutex_spin_on_owner(struct mutex *lock, struct thread_info *owner) cpu_relax(); } -out: + return 1; } #endif |