From: Paul E. McKenney <paulmck@kernel.org>
Date: Thu, 15 Aug 2019 18:43:53 +0000 (-0700)
Subject: rcutorture: Make in-kernel-loop testing more brutal
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=fbbd5e358cecb5fa490550ace66463517a7577e8;p=linux.git

rcutorture: Make in-kernel-loop testing more brutal

The rcu_torture_fwd_prog_nr() tests the ability of RCU to tolerate
in-kernel busy loops.  It invokes rcu_torture_fwd_prog_cond_resched()
within its delay loop, which, in PREEMPT && NO_HZ_FULL kernels results
in the occasional direct call to schedule().  Now, this direct call to
schedule() is appropriate for call_rcu() flood testing, in which either
the kernel should restrain itself or userspace transitions will supply
the needed restraint.  But in pure in-kernel loops, the occasional
cond_resched() should do the job.

This commit therefore makes rcu_torture_fwd_prog_nr() use cond_resched()
instead of rcu_torture_fwd_prog_cond_resched() in order to increase the
brutality of this aspect of rcutorture testing.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---

diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 5ac4672938032..df1caa93ee63f 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -1806,7 +1806,7 @@ static void rcu_torture_fwd_prog_nr(int *tested, int *tested_tries)
 		udelay(10);
 		cur_ops->readunlock(idx);
 		if (!fwd_progress_need_resched || need_resched())
-			rcu_torture_fwd_prog_cond_resched(1);
+			cond_resched();
 	}
 	(*tested_tries)++;
 	if (!time_before(jiffies, stopat) &&