rcutorture: Add per-reader-segment preemption diagnostics

For preemptible RCU, this commit adds an indication for each
reader segments to whether the rcu_torture_reader() task was
on the ->blkd_tasks lists, though only in kernels built with
CONFIG_RCU_TORTURE_TEST_LOG_CPU=y.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
This commit is contained in:
Paul E. McKenney 2024-11-13 19:10:19 -08:00 committed by Uladzislau Rezki (Sony)
parent 885a6f4729
commit 223f16b87d

View File

@ -464,10 +464,8 @@ rcu_read_delay(struct torture_random_state *rrsp, struct rt_read_seg *rtrsp)
rtrsp->rt_delay_us = shortdelay_us;
}
if (!preempt_count() &&
!(torture_random(rrsp) % (nrealreaders * 500))) {
!(torture_random(rrsp) % (nrealreaders * 500)))
torture_preempt_schedule(); /* QS only if preemptible. */
rtrsp->rt_preempted = true;
}
}
static void rcu_torture_read_unlock(int idx)
@ -1961,8 +1959,11 @@ static void rcutorture_one_extend(int *readstate, int newstate, bool insoftirq,
if (IS_ENABLED(CONFIG_RCU_TORTURE_TEST_LOG_CPU)) {
int cpu = raw_smp_processor_id();
rtrsp->rt_cpu = cpu;
if (!first)
if (!first) {
rtrsp[-1].rt_end_cpu = cpu;
if (cur_ops->reader_blocked)
rtrsp[-1].rt_preempted = cur_ops->reader_blocked();
}
}
/*