From 682189a3f874db57b3e755512f2a2953f61fc54e Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Mon, 16 Nov 2020 17:10:39 -0800 Subject: [PATCH] rcutorture: Make rcu_torture_fakewriter() use blocking wait primitives Full testing of the new SRCU polling API requires that the fake writers also use it in order to test concurrent calls to all of the API members, especially start_poll_synchronize_srcu(). This commit makes rcu_torture_fakewriter() use all available blocking grace-period-wait primitives available from the RCU flavor under test. Link: https://lore.kernel.org/rcu/20201112201547.GF3365678@moria.home.lan/ Reported-by: Kent Overstreet Signed-off-by: Paul E. McKenney --- kernel/rcu/rcutorture.c | 40 ++++++++++++++++++++++++++++++++-------- 1 file changed, 32 insertions(+), 8 deletions(-) diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index 0d257e2dc9c6..03bdf6752fe4 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -1289,6 +1289,8 @@ rcu_torture_writer(void *arg) static int rcu_torture_fakewriter(void *arg) { + unsigned long gp_snap; + int i; DEFINE_TORTURE_RANDOM(rand); VERBOSE_TOROUT_STRING("rcu_torture_fakewriter task started"); @@ -1300,15 +1302,37 @@ rcu_torture_fakewriter(void *arg) if (cur_ops->cb_barrier != NULL && torture_random(&rand) % (nfakewriters * 8) == 0) { cur_ops->cb_barrier(); - } else if (gp_normal == gp_exp) { - if (cur_ops->sync && torture_random(&rand) & 0x80) - cur_ops->sync(); - else if (cur_ops->exp_sync) + } else { + switch (synctype[torture_random(&rand) % nsynctypes]) { + case RTWS_DEF_FREE: + break; + case RTWS_EXP_SYNC: cur_ops->exp_sync(); - } else if (gp_normal && cur_ops->sync) { - cur_ops->sync(); - } else if (cur_ops->exp_sync) { - cur_ops->exp_sync(); + break; + case RTWS_COND_GET: + gp_snap = cur_ops->get_gp_state(); + i = torture_random(&rand) % 16; + if (i != 0) + schedule_timeout_interruptible(i); + udelay(torture_random(&rand) % 1000); + cur_ops->cond_sync(gp_snap); + break; + case RTWS_POLL_GET: + gp_snap = cur_ops->start_gp_poll(); + while (!cur_ops->poll_gp_state(gp_snap)) { + i = torture_random(&rand) % 16; + if (i != 0) + schedule_timeout_interruptible(i); + udelay(torture_random(&rand) % 1000); + } + break; + case RTWS_SYNC: + cur_ops->sync(); + break; + default: + WARN_ON_ONCE(1); + break; + } } stutter_wait("rcu_torture_fakewriter"); } while (!torture_must_stop());