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authorPaul E. McKenney2019-08-04 13:17:35 -0700
committerPaul E. McKenney2019-10-05 10:46:05 -0700
commit79ba7ff5a9925f5c170f51ed7a96d1475eb6c27f (patch)
treebbc1dd08082d1b70a578c253ca1759ca2d61a4e5 /kernel/rcu
parent96926686deab853bcacf887501f4ed958e38666b (diff)
rcutorture: Emulate dyntick aspect of userspace nohz_full sojourn
During an actual call_rcu() flood, there would be frequent trips to userspace (in-kernel call_rcu() floods must be otherwise housebroken). Userspace execution on nohz_full CPUs implies an RCU dyntick idle/not-idle transition pair, so this commit adds emulation of that pair. Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'kernel/rcu')
-rw-r--r--kernel/rcu/rcutorture.c11
-rw-r--r--kernel/rcu/tree.c1
2 files changed, 12 insertions, 0 deletions
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index ab61f5c1353b..49ad88765ed2 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -1761,6 +1761,11 @@ static unsigned long rcu_torture_fwd_prog_cbfree(void)
kfree(rfcp);
freed++;
rcu_torture_fwd_prog_cond_resched(freed);
+ if (tick_nohz_full_enabled()) {
+ local_irq_save(flags);
+ rcu_momentary_dyntick_idle();
+ local_irq_restore(flags);
+ }
}
return freed;
}
@@ -1835,6 +1840,7 @@ static void rcu_torture_fwd_prog_nr(int *tested, int *tested_tries)
static void rcu_torture_fwd_prog_cr(void)
{
unsigned long cver;
+ unsigned long flags;
unsigned long gps;
int i;
long n_launders;
@@ -1894,6 +1900,11 @@ static void rcu_torture_fwd_prog_cr(void)
}
cur_ops->call(&rfcp->rh, rcu_torture_fwd_cb_cr);
rcu_torture_fwd_prog_cond_resched(n_launders + n_max_cbs);
+ if (tick_nohz_full_enabled()) {
+ local_irq_save(flags);
+ rcu_momentary_dyntick_idle();
+ local_irq_restore(flags);
+ }
}
stoppedat = jiffies;
n_launders_cb_snap = READ_ONCE(n_launders_cb);
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 7c67ea561b36..66354ef776aa 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -375,6 +375,7 @@ void rcu_momentary_dyntick_idle(void)
WARN_ON_ONCE(!(special & RCU_DYNTICK_CTRL_CTR));
rcu_preempt_deferred_qs(current);
}
+EXPORT_SYMBOL_GPL(rcu_momentary_dyntick_idle);
/**
* rcu_is_cpu_rrupt_from_idle - see if interrupted from idle