From 4ffa66992476c94d8b4d33b2c792d336a400ada2 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Thu, 30 Jun 2016 11:56:38 -0700 Subject: [PATCH] torture: Add task state to writer-task stall printk()s This commit adds a dump of the scheduler state for stalled rcutorture writer tasks. This addition provides yet more debug for the intermittent "failures to proceed", where grace periods move ahead but the rcutorture writer tasks fail to do so. Signed-off-by: Paul E. McKenney --- kernel/rcu/rcutorture.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index 971e2b138063..f0f32f888ec5 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -1238,6 +1238,7 @@ rcu_torture_stats_print(void) long pipesummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 }; long batchsummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 }; static unsigned long rtcv_snap = ULONG_MAX; + struct task_struct *wtp; for_each_possible_cpu(cpu) { for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { @@ -1312,10 +1313,12 @@ rcu_torture_stats_print(void) rcutorture_get_gp_data(cur_ops->ttype, &flags, &gpnum, &completed); - pr_alert("??? Writer stall state %s(%d) g%lu c%lu f%#x\n", + wtp = READ_ONCE(writer_task); + pr_alert("??? Writer stall state %s(%d) g%lu c%lu f%#x ->state %#lx\n", rcu_torture_writer_state_getname(), rcu_torture_writer_state, - gpnum, completed, flags); + gpnum, completed, flags, + wtp == NULL ? ~0UL : wtp->state); show_rcu_gp_kthreads(); rcu_ftrace_dump(DUMP_ALL); } -- 2.34.1