Commit-ID: 8695159967957015f8dfb49315d6f88e111d90e0 Gitweb: http://git.kernel.org/tip/8695159967957015f8dfb49315d6f88e111d90e0 Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx> AuthorDate: Tue, 22 Jun 2010 11:44:53 +0200 Committer: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx> CommitDate: Wed, 23 Jun 2010 15:14:09 -0700 sched: silence PROVE_RCU in sched_fork() Because cgroup_fork() is ran before sched_fork() [ from copy_process() ] and the child's pid is not yet visible the child is pinned to its cgroup. Therefore we can silence this warning. A nicer solution would be moving cgroup_fork() to right after dup_task_struct() and exclude PF_STARTING from task_subsys_state(). Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> Reviewed-by: Li Zefan <lizf@xxxxxxxxxxxxxx> Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx> --- kernel/sched.c | 9 +++++++++ 1 files changed, 9 insertions(+), 0 deletions(-) diff --git a/kernel/sched.c b/kernel/sched.c index f8b8996..a2d215d 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -2494,7 +2494,16 @@ void sched_fork(struct task_struct *p, int clone_flags) if (p->sched_class->task_fork) p->sched_class->task_fork(p); + /* + * The child is not yet in the pid-hash so no cgroup attach races, + * and the cgroup is pinned to this child due to cgroup_fork() + * is ran before sched_fork(). + * + * Silence PROVE_RCU. + */ + rcu_read_lock(); set_task_cpu(p, cpu); + rcu_read_unlock(); #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) if (likely(sched_info_on())) -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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