rcu: Move irq-disabled stall-warning checking to tree_stall.h

The rcu_iw_handler() function's sole purpose in life is to indicate
whether a stalled CPU had interrupts disabled, so it belongs in
kernel/rcu/tree_stall.h.  This commit therefore makes that move,
clarifying its header comment while in the area.

Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
This commit is contained in:
Paul E. McKenney 2019-01-14 10:19:20 -08:00
parent e23344c2ca
commit 7ac1907c9e
3 changed files with 21 additions and 21 deletions

View File

@ -1031,27 +1031,6 @@ static int dyntick_save_progress_counter(struct rcu_data *rdp)
return 0;
}
/*
* Handler for the irq_work request posted when a grace period has
* gone on for too long, but not yet long enough for an RCU CPU
* stall warning. Set state appropriately, but just complain if
* there is unexpected state on entry.
*/
static void rcu_iw_handler(struct irq_work *iwp)
{
struct rcu_data *rdp;
struct rcu_node *rnp;
rdp = container_of(iwp, struct rcu_data, rcu_iw);
rnp = rdp->mynode;
raw_spin_lock_rcu_node(rnp);
if (!WARN_ON_ONCE(!rdp->rcu_iw_pending)) {
rdp->rcu_iw_gp_seq = rnp->gp_seq;
rdp->rcu_iw_pending = false;
}
raw_spin_unlock_rcu_node(rnp);
}
/*
* Return true if the specified CPU has passed through a quiescent
* state by virtue of being in or having passed through an dynticks

View File

@ -443,4 +443,5 @@ static void rcu_dynticks_task_exit(void);
/* Forward declarations for tree_stall.h */
static void record_gp_stall_check_time(void);
static void rcu_iw_handler(struct irq_work *iwp);
static void check_cpu_stall(struct rcu_data *rdp);

View File

@ -139,6 +139,26 @@ static void rcu_stall_kick_kthreads(void)
}
}
/*
* Handler for the irq_work request posted about halfway into the RCU CPU
* stall timeout, and used to detect excessive irq disabling. Set state
* appropriately, but just complain if there is unexpected state on entry.
*/
static void rcu_iw_handler(struct irq_work *iwp)
{
struct rcu_data *rdp;
struct rcu_node *rnp;
rdp = container_of(iwp, struct rcu_data, rcu_iw);
rnp = rdp->mynode;
raw_spin_lock_rcu_node(rnp);
if (!WARN_ON_ONCE(!rdp->rcu_iw_pending)) {
rdp->rcu_iw_gp_seq = rnp->gp_seq;
rdp->rcu_iw_pending = false;
}
raw_spin_unlock_rcu_node(rnp);
}
//////////////////////////////////////////////////////////////////////////////
//
// Printing RCU CPU stall warnings