diff options
| author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2018-07-09 15:50:16 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2018-08-30 16:03:39 -0700 |
| commit | a0ef9ec24144799b5b47fa54c38f9a0f9dfe9a59 (patch) | |
| tree | a318be5c9dee9890d883744e8abbd7fc49101d7b /kernel/rcu/tree.c | |
| parent | 92aa39e9dc77481b90cbef25e547d66cab901496 (diff) | |
rcu: Provide improved interrupt-from-idle check in rcu_check_callbacks()
The patch making need_resched() respond to urgent RCU-QS needs used
is_idle_task(current) to detect an interrupt from idle, which does work
reasonably, but is (in theory at least) vulnerable to loops containing
need_resched() invoked from within RCU_NONIDLE() or its tracepoint
equivalent. This commit therefore moves rcu_is_cpu_rrupt_from_idle()
to a place from which rcu_check_callbacks() can invoke it and replaces
the is_idle_task(current) with rcu_is_cpu_rrupt_from_idle().
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'kernel/rcu/tree.c')
| -rw-r--r-- | kernel/rcu/tree.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index f47ac7a4719f..77d2cbf7c831 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -2474,7 +2474,7 @@ void rcu_check_callbacks(int user) /* The load-acquire pairs with the store-release setting to true. */ if (smp_load_acquire(this_cpu_ptr(&rcu_dynticks.rcu_urgent_qs))) { /* Idle and userspace execution already are quiescent states. */ - if (!is_idle_task(current) && !user) { + if (!rcu_is_cpu_rrupt_from_idle() && !user) { set_tsk_need_resched(current); set_preempt_need_resched(); } |