mirrors/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2024-09-30 22:26:55 +00:00
Code Issues Releases Wiki Activity

rcutorture: Add RCU Tasks Trace and SRCU deadlock scenarios

Browse source 
Add a test number 3 that creates deadlock cycles involving one RCU
Tasks Trace step and L-1 SRCU steps.  Please note that lockdep will not
detect these deadlocks until synchronize_rcu_tasks_trace() is marked
with lockdep's new "sync" annotation, which will probably not happen
until some time after these markings prove their worth on SRCU.

Please note that these tests are available only in kernels built with
CONFIG_TASKS_TRACE_RCU=y.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
This commit is contained in:
Paul E. McKenney 2023-01-24 09:43:15 -08:00 committed by Boqun Feng
parent d94f12e8a4
commit 6e2044887b
1 changed files with 35 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

36
kernel/rcu/rcutorture.c
View file

@ -3604,12 +3604,46 @@ static void rcu_torture_init_srcu_lockdep(void)
return;
}
#ifdef CONFIG_TASKS_TRACE_RCU
if (testtype == 3) {
pr_info("%s: test_srcu_lockdep = %05d: SRCU and Tasks Trace RCU %d-way %sdeadlock.\n",
__func__, test_srcu_lockdep, cyclelen, deadlock ? "" : "non-");
if (deadlock && cyclelen == 1)
pr_info("%s: Expect hang.\n", __func__);
for (i = 0; i < cyclelen; i++) {
char *fl = i == 0 ? "rcu_read_lock_trace" : "srcu_read_lock";
char *fs = i == cyclelen - 1 ? "synchronize_rcu_tasks_trace"
: "synchronize_srcu";
char *fu = i == 0 ? "rcu_read_unlock_trace" : "srcu_read_unlock";
j = srcu_lockdep_next(__func__, fl, fs, fu, i, cyclelen, deadlock);
if (i == 0)
rcu_read_lock_trace();
else
idx = srcu_read_lock(srcus[i]);
if (j >= 0) {
if (i == cyclelen - 1)
synchronize_rcu_tasks_trace();
else
synchronize_srcu(srcus[j]);
}
if (i == 0)
rcu_read_unlock_trace();
else
srcu_read_unlock(srcus[i], idx);
}
return;
}
#endif // #ifdef CONFIG_TASKS_TRACE_RCU
err_out:
pr_info("%s: test_srcu_lockdep = %05d does nothing.\n", __func__, test_srcu_lockdep);
pr_info("%s: test_srcu_lockdep = DNNL.\n", __func__);
pr_info("%s: D: Deadlock if nonzero.\n", __func__);
pr_info("%s: NN: Test number, 0=SRCU, 1=SRCU/mutex, 2=SRCU/rwsem.\n", __func__);
pr_info("%s: NN: Test number, 0=SRCU, 1=SRCU/mutex, 2=SRCU/rwsem, 3=SRCU/Tasks Trace RCU.\n", __func__);
pr_info("%s: L: Cycle length.\n", __func__);
if (!IS_ENABLED(CONFIG_TASKS_TRACE_RCU))
pr_info("%s: NN=3 disallowed because kernel is built with CONFIG_TASKS_TRACE_RCU=n\n", __func__);
}
static int __init