Messages in this thread | | | Date | Tue, 7 Apr 2015 15:13:35 -0700 | From | "Paul E. McKenney" <> | Subject | Re: [PATCH] rcu: Fix missing task information during rcu-preempt stall |
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On Tue, Apr 07, 2015 at 01:03:13PM -0700, Patrick Daly wrote: > 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.
Good catch, thank you!
Queued for v4.2.
Thanx, Paul
> Signed-off-by: Patrick Daly <pdaly@codeaurora.org> > --- > kernel/rcu/tree_plugin.h | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h > index d1dda52..9fbecdc 100644 > --- a/kernel/rcu/tree_plugin.h > +++ b/kernel/rcu/tree_plugin.h > @@ -459,7 +459,7 @@ 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); > @@ -524,7 +524,7 @@ 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) { > printk(KERN_CONT " P%d", t->pid); > -- > The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, > a Linux Foundation Collaborative Project >
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