From: "Paul E. McKenney" <paulmck@xxxxxxxxxx>
This commit adds an rcutorture.reader_flavor parameter whose bits
correspond to reader flavors. For example, SRCU's readers are 0x1 for
normal and 0x2 for NMI-safe.
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
Cc: Alexei Starovoitov <ast@xxxxxxxxxx>
Cc: Andrii Nakryiko <andrii@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Kent Overstreet <kent.overstreet@xxxxxxxxx>
Cc: <bpf@xxxxxxxxxxxxxxx>
Reviewed-by: Neeraj Upadhyay <Neeraj.Upadhyay@xxxxxxx>
Signed-off-by: Frederic Weisbecker <frederic@xxxxxxxxxx>
---
.../admin-guide/kernel-parameters.txt | 8 +++++
kernel/rcu/rcutorture.c | 30 ++++++++++++++-----
2 files changed, 30 insertions(+), 8 deletions(-)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 1518343bbe22..52922727006f 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -5426,6 +5426,14 @@
The delay, in seconds, between successive
read-then-exit testing episodes.
+ rcutorture.reader_flavor= [KNL]
+ A bit mask indicating which readers to use.
+ If there is more than one bit set, the readers
+ are entered from low-order bit up, and are
+ exited in the opposite order. For SRCU, the
+ 0x1 bit is normal readers and the 0x2 bit is
+ for NMI-safe readers.
+
rcutorture.shuffle_interval= [KNL]
Set task-shuffle interval (s). Shuffling tasks
allows some CPUs to go into dyntick-idle mode
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index f96ab98f8182..405decec3367 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -111,6 +111,7 @@ torture_param(int, nocbs_nthreads, 0, "Number of NOCB toggle threads, 0 to disab
torture_param(int, nocbs_toggle, 1000, "Time between toggling nocb state (ms)");
torture_param(int, read_exit_delay, 13, "Delay between read-then-exit episodes (s)");
torture_param(int, read_exit_burst, 16, "# of read-then-exit bursts per episode, zero to disable");
+torture_param(int, reader_flavor, 0x1, "Reader flavors to use, one per bit.");
torture_param(int, shuffle_interval, 3, "Number of seconds between shuffles");
torture_param(int, shutdown_secs, 0, "Shutdown time (s), <= zero to disable.");
torture_param(int, stall_cpu, 0, "Stall duration (s), zero to disable.");
@@ -644,10 +645,20 @@ static void srcu_get_gp_data(int *flags, unsigned long *gp_seq)
static int srcu_torture_read_lock(void)
{
- if (cur_ops == &srcud_ops)
- return srcu_read_lock_nmisafe(srcu_ctlp);
- else
- return srcu_read_lock(srcu_ctlp);
+ int idx;
+ int ret = 0;
+
+ if ((reader_flavor & 0x1) || !(reader_flavor & 0x7)) {
+ idx = srcu_read_lock(srcu_ctlp);
+ WARN_ON_ONCE(idx & ~0x1);
+ ret += idx;
+ }
+ if (reader_flavor & 0x2) {
+ idx = srcu_read_lock_nmisafe(srcu_ctlp);
+ WARN_ON_ONCE(idx & ~0x1);
+ ret += idx << 1;
+ }
+ return ret;
}
static void
@@ -671,10 +682,11 @@ srcu_read_delay(struct torture_random_state *rrsp, struct rt_read_seg *rtrsp)
static void srcu_torture_read_unlock(int idx)
{
- if (cur_ops == &srcud_ops)
- srcu_read_unlock_nmisafe(srcu_ctlp, idx);
- else
- srcu_read_unlock(srcu_ctlp, idx);
+ WARN_ON_ONCE((reader_flavor && (idx & ~reader_flavor)) || (!reader_flavor && (idx & ~0x1)));
+ if (reader_flavor & 0x2)
+ srcu_read_unlock_nmisafe(srcu_ctlp, (idx & 0x2) >> 1);
+ if ((reader_flavor & 0x1) || !(reader_flavor & 0x7))
+ srcu_read_unlock(srcu_ctlp, idx & 0x1);
}
static int torture_srcu_read_lock_held(void)
@@ -2389,6 +2401,7 @@ rcu_torture_print_module_parms(struct rcu_torture_ops *cur_ops, const char *tag)
"n_barrier_cbs=%d "
"onoff_interval=%d onoff_holdoff=%d "
"read_exit_delay=%d read_exit_burst=%d "
+ "reader_flavor=%x "
"nocbs_nthreads=%d nocbs_toggle=%d "
"test_nmis=%d\n",
torture_type, tag, nrealreaders, nfakewriters,
@@ -2401,6 +2414,7 @@ rcu_torture_print_module_parms(struct rcu_torture_ops *cur_ops, const char *tag)
n_barrier_cbs,
onoff_interval, onoff_holdoff,
read_exit_delay, read_exit_burst,
+ reader_flavor,
nocbs_nthreads, nocbs_toggle,
test_nmis);
}
--
2.46.0
