diff options
| author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2016-12-01 11:31:31 -0800 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2016-12-28 12:05:37 -0800 |
| commit | 3e9c1bc1ed0a49f09c4a34c05b264c9dc4611a78 (patch) | |
| tree | 4218a2ef69eec88036564b46ce0e4f24c0c7290b /kernel | |
| parent | 9b910e3e99df68ea86a210298a9c1bc8cead194e (diff) | |
rcu: Add long-term CPU kicking
Commit d2db185bfee8 ("rcu: Remove short-term CPU kicking") removed
frequent calls to resched_cpu(), which means that the only time
resched_cpu() is invoked is after an RCU CPU stall warning. Although
this is good from an avoid-IPIs perspective, we should try to break
things loose -before- splatting. This commit therefore starts invoking
resched_cpu() for each holdout at each force-quiescent-state interval
that is more than halfway through the stall-warning interval.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/rcu/tree.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 91a68e4e6671..07478ecabcd9 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -1345,6 +1345,13 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp, rdp->rsp->jiffies_resched += 5; /* Re-enable beating. */ } + /* + * If more than halfway to RCU CPU stall-warning time, do + * a resched_cpu() to try to loosen things up a bit. + */ + if (jiffies - rdp->rsp->gp_start > rcu_jiffies_till_stall_check() / 2) + resched_cpu(rdp->cpu); + return 0; } |