From ef1ef3d47677dc191b88650a9f7f91413452cc1b Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Tue, 31 Jan 2023 12:08:54 -0800 Subject: rcuscale: Move shutdown from wait_event() to wait_event_idle() The rcu_scale_shutdown() and kfree_scale_shutdown() kthreads/functions use wait_event() to wait for the rcuscale test to complete. However, each updater thread in such a test waits for at least 100 grace periods. If each grace period takes more than 1.2 seconds, which is long, but not insanely so, this can trigger the hung-task timeout. This commit therefore replaces those wait_event() calls with calls to wait_event_idle(), which do not trigger the hung-task timeout. Reported-by: kernel test robot Reported-by: Liam Howlett Signed-off-by: Paul E. McKenney Tested-by: Yujie Liu Signed-off-by: Boqun Feng --- kernel/rcu/rcuscale.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) (limited to 'kernel/rcu/rcuscale.c') diff --git a/kernel/rcu/rcuscale.c b/kernel/rcu/rcuscale.c index 91fb5905a008..4120f94030c3 100644 --- a/kernel/rcu/rcuscale.c +++ b/kernel/rcu/rcuscale.c @@ -631,8 +631,7 @@ static int compute_real(int n) static int rcu_scale_shutdown(void *arg) { - wait_event(shutdown_wq, - atomic_read(&n_rcu_scale_writer_finished) >= nrealwriters); + wait_event_idle(shutdown_wq, atomic_read(&n_rcu_scale_writer_finished) >= nrealwriters); smp_mb(); /* Wake before output. */ rcu_scale_cleanup(); kernel_power_off(); @@ -771,8 +770,8 @@ kfree_scale_cleanup(void) static int kfree_scale_shutdown(void *arg) { - wait_event(shutdown_wq, - atomic_read(&n_kfree_scale_thread_ended) >= kfree_nrealthreads); + wait_event_idle(shutdown_wq, + atomic_read(&n_kfree_scale_thread_ended) >= kfree_nrealthreads); smp_mb(); /* Wake before output. */ -- cgit From 936c7e19c695d624adac28ea390fd8d53c653542 Mon Sep 17 00:00:00 2001 From: "Uladzislau Rezki (Sony)" Date: Wed, 1 Feb 2023 16:09:52 +0100 Subject: rcuscale: Rename kfree_rcu() to kfree_rcu_mightsleep() The kfree_rcu() and kvfree_rcu() macros' single-argument forms are deprecated. Therefore switch to the new kfree_rcu_mightsleep() and kvfree_rcu_mightsleep() variants. The goal is to avoid accidental use of the single-argument forms, which can introduce functionality bugs in atomic contexts and latency bugs in non-atomic contexts. Acked-by: Joel Fernandes (Google) Signed-off-by: Uladzislau Rezki (Sony) Signed-off-by: Paul E. McKenney Signed-off-by: Joel Fernandes (Google) --- kernel/rcu/rcuscale.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/rcu/rcuscale.c') diff --git a/kernel/rcu/rcuscale.c b/kernel/rcu/rcuscale.c index 91fb5905a008..98b75995b680 100644 --- a/kernel/rcu/rcuscale.c +++ b/kernel/rcu/rcuscale.c @@ -716,7 +716,7 @@ kfree_scale_thread(void *arg) // is tested. if ((kfree_rcu_test_single && !kfree_rcu_test_double) || (kfree_rcu_test_both && torture_random(&tr) & 0x800)) - kfree_rcu(alloc_ptr); + kfree_rcu_mightsleep(alloc_ptr); else kfree_rcu(alloc_ptr, rh); } -- cgit