From 27ba76e164fc83ffe6ceeb0415c427ad1191af6c Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Sun, 4 Apr 2021 17:23:36 -0700 Subject: [PATCH] rcu: Add ->gp_max to show_rcu_gp_kthreads() output This commit adds ->gp_max to show_rcu_gp_kthreads() output in order to better diagnose RCU priority boosting failures. Signed-off-by: Paul E. McKenney --- kernel/rcu/tree_stall.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/rcu/tree_stall.h b/kernel/rcu/tree_stall.h index fb4702570316..a4e2bb3bdce7 100644 --- a/kernel/rcu/tree_stall.h +++ b/kernel/rcu/tree_stall.h @@ -737,12 +737,13 @@ void show_rcu_gp_kthreads(void) jr = j - data_race(rcu_state.gp_req_activity); js = j - data_race(rcu_state.gp_start); jw = j - data_race(rcu_state.gp_wake_time); - pr_info("%s: wait state: %s(%d) ->state: %#lx ->rt_priority %u delta ->gp_start %lu ->gp_activity %lu ->gp_req_activity %lu ->gp_wake_time %lu ->gp_wake_seq %ld ->gp_seq %ld ->gp_seq_needed %ld ->gp_flags %#x\n", + pr_info("%s: wait state: %s(%d) ->state: %#lx ->rt_priority %u delta ->gp_start %lu ->gp_activity %lu ->gp_req_activity %lu ->gp_wake_time %lu ->gp_wake_seq %ld ->gp_seq %ld ->gp_seq_needed %ld ->gp_max %lu ->gp_flags %#x\n", rcu_state.name, gp_state_getname(rcu_state.gp_state), rcu_state.gp_state, t ? t->state : 0x1ffffL, t ? t->rt_priority : 0xffU, js, ja, jr, jw, (long)data_race(rcu_state.gp_wake_seq), (long)data_race(rcu_state.gp_seq), (long)data_race(rcu_get_root()->gp_seq_needed), + data_race(rcu_state.gp_max), data_race(rcu_state.gp_flags)); rcu_for_each_node_breadth_first(rnp) { if (ULONG_CMP_GE(READ_ONCE(rcu_state.gp_seq),