rcu: Fix missing task information during rcu-preempt stall (82efed06) · Commits · 戴 / test

The first item list_for_each_entry_continue(alist) iterates over is alist->next, rather than alist itself. Consequently, rcu_print_detail_task_stall_rnp() skips the task referenced by gp_tasks. Use gp_tasks->prev as the argument to list_for_each_entry_continue() instead. Signed-off-by:

Patrick Daly <pdaly@codeaurora.org> Signed-off-by:

Paul E. McKenney <paulmck@linux.vnet.ibm.com>

kernel/rcu/tree_plugin.h

+2 −2

Original line number	Diff line number	Diff line
		@@ -395,7 +395,7 @@ static void rcu_print_detail_task_stall_rnp(struct rcu_node *rnp)
		raw_spin_unlock_irqrestore(&rnp->lock, flags);
		return;
		}
		t = list_entry(rnp->gp_tasks,
		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)
		sched_show_task(t);
		@@ -452,7 +452,7 @@ 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);
		t = list_entry(rnp->gp_tasks,
		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);

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