The rcu_print_detail_task_stall(), rcu_print_task_stall_begin(), and rcu_print_task_stall_end() functions were defined to allow long-gone Kconfig options to provide an abbreviated RCU CPU stall warning printout. This commit saves a few lines of code by inlining them into their sole callers.
While in the area, a useless call of rcu_print_detail_task_stall_rnp() on the root rcu_node structure was eliminated. If there is only one rcu_node structure, its tasks get printed twice, but if there are more, the root rcu_node structure is guaranteed to have an empty list of blocked tasks, hence the uselessness. (Long ago, root rcu_node structures with non-empty ->blkd_tasks lists could happen, but no longer.) Signed-off-by: Paul E. McKenney <[email protected]> --- kernel/rcu/tree.h | 1 - kernel/rcu/tree_stall.h | 36 +++++++----------------------------- 2 files changed, 7 insertions(+), 30 deletions(-) diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h index 3c4e26fff806..c6df9a13dd06 100644 --- a/kernel/rcu/tree.h +++ b/kernel/rcu/tree.h @@ -445,7 +445,6 @@ static void rcu_dynticks_task_enter(void); static void rcu_dynticks_task_exit(void); /* Forward declarations for tree_stall.h */ -static void rcu_print_detail_task_stall(void); static int rcu_print_task_stall(struct rcu_node *rnp); static void record_gp_stall_check_time(void); static void check_cpu_stall(struct rcu_data *rdp); diff --git a/kernel/rcu/tree_stall.h b/kernel/rcu/tree_stall.h index e0e73f493363..b476786b8ef7 100644 --- a/kernel/rcu/tree_stall.h +++ b/kernel/rcu/tree_stall.h @@ -94,30 +94,6 @@ static void rcu_print_detail_task_stall_rnp(struct rcu_node *rnp) raw_spin_unlock_irqrestore_rcu_node(rnp, flags); } -/* - * Dump detailed information for all tasks blocking the current RCU - * grace period. - */ -static void rcu_print_detail_task_stall(void) -{ - struct rcu_node *rnp = rcu_get_root(); - - rcu_print_detail_task_stall_rnp(rnp); - rcu_for_each_leaf_node(rnp) - rcu_print_detail_task_stall_rnp(rnp); -} - -static void rcu_print_task_stall_begin(struct rcu_node *rnp) -{ - pr_err("\tTasks blocked on level-%d rcu_node (CPUs %d-%d):", - rnp->level, rnp->grplo, rnp->grphi); -} - -static void rcu_print_task_stall_end(void) -{ - pr_cont("\n"); -} - /* * Scan the current list of tasks blocked within RCU read-side critical * sections, printing out the tid of each. @@ -129,14 +105,15 @@ static int rcu_print_task_stall(struct rcu_node *rnp) if (!rcu_preempt_blocked_readers_cgp(rnp)) return 0; - rcu_print_task_stall_begin(rnp); + pr_err("\tTasks blocked on level-%d rcu_node (CPUs %d-%d):", + rnp->level, rnp->grplo, rnp->grphi); t = list_entry(rnp->gp_tasks->prev, struct task_struct, rcu_node_entry); list_for_each_entry_continue(t, &rnp->blkd_tasks, rcu_node_entry) { pr_cont(" P%d", t->pid); ndetected++; } - rcu_print_task_stall_end(); + pr_cont("\n"); return ndetected; } @@ -146,7 +123,7 @@ static int rcu_print_task_stall(struct rcu_node *rnp) * Because preemptible RCU does not exist, we never have to check for * tasks blocked within RCU read-side critical sections. */ -static void rcu_print_detail_task_stall(void) +static void rcu_print_detail_task_stall_rnp(struct rcu_node *rnp) { } @@ -253,7 +230,7 @@ static void print_other_cpu_stall(unsigned long gp_seq) unsigned long gpa; unsigned long j; int ndetected = 0; - struct rcu_node *rnp = rcu_get_root(); + struct rcu_node *rnp; long totqlen = 0; /* Kick and suppress, if so configured. */ @@ -291,7 +268,8 @@ static void print_other_cpu_stall(unsigned long gp_seq) rcu_dump_cpu_stacks(); /* Complain about tasks blocking the grace period. */ - rcu_print_detail_task_stall(); + rcu_for_each_leaf_node(rnp) + rcu_print_detail_task_stall_rnp(rnp); } else { if (rcu_seq_current(&rcu_state.gp_seq) != gp_seq) { pr_err("INFO: Stall ended before state dump start\n"); -- 2.17.1
