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| author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2018-05-08 23:18:57 +0200 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2018-07-13 00:39:09 +0200 |
| commit | 577389423187d8b51dfe6199297e579a3419b72b (patch) | |
| tree | 8cb47b71dc71d38c6f36f698281bf8a05b929393 /kernel/rcu/tree.h | |
| parent | rcu: Add up-tree information to dump_blkd_tasks() diagnostics (diff) | |
| download | linux-577389423187d8b51dfe6199297e579a3419b72b.tar.xz linux-577389423187d8b51dfe6199297e579a3419b72b.zip | |
rcu: Add CPU online/offline state to dump_blkd_tasks()
Interactions between CPU-hotplug operations and grace-period
initialization can result in dump_blkd_tasks(). One of the first
debugging actions in this case is to search back in dmesg to work
out which of the affected rcu_node structure's CPUs are online and to
determine the last CPU-hotplug operation affecting any of those CPUs.
This can be laborious and error-prone, especially when console output
is lost.
This commit therefore causes dump_blkd_tasks() to dump the state of
the affected rcu_node structure's CPUs and the last grace period during
which the last offline and online operation affected each of these CPUs.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'kernel/rcu/tree.h')
| -rw-r--r-- | kernel/rcu/tree.h | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h index 795d469c6f67..f52bc059bfec 100644 --- a/kernel/rcu/tree.h +++ b/kernel/rcu/tree.h @@ -255,12 +255,16 @@ struct rcu_data { /* Leader CPU takes GP-end wakeups. */ #endif /* #ifdef CONFIG_RCU_NOCB_CPU */ - /* 7) RCU CPU stall data. */ + /* 7) Diagnostic data, including RCU CPU stall warnings. */ unsigned int softirq_snap; /* Snapshot of softirq activity. */ /* ->rcu_iw* fields protected by leaf rcu_node ->lock. */ struct irq_work rcu_iw; /* Check for non-irq activity. */ bool rcu_iw_pending; /* Is ->rcu_iw pending? */ unsigned long rcu_iw_gp_seq; /* ->gp_seq associated with ->rcu_iw. */ + unsigned long rcu_ofl_gp_seq; /* ->gp_seq at last offline. */ + short rcu_ofl_gp_flags; /* ->gp_flags at last offline. */ + unsigned long rcu_onl_gp_seq; /* ->gp_seq at last online. */ + short rcu_onl_gp_flags; /* ->gp_flags at last online. */ int cpu; struct rcu_state *rsp; @@ -431,11 +435,13 @@ static bool rcu_preempt_has_tasks(struct rcu_node *rnp); static void rcu_print_detail_task_stall(struct rcu_state *rsp); static int rcu_print_task_stall(struct rcu_node *rnp); static int rcu_print_task_exp_stall(struct rcu_node *rnp); -static void rcu_preempt_check_blocked_tasks(struct rcu_node *rnp); +static void rcu_preempt_check_blocked_tasks(struct rcu_state *rsp, + struct rcu_node *rnp); static void rcu_preempt_check_callbacks(void); void call_rcu(struct rcu_head *head, rcu_callback_t func); static void __init __rcu_init_preempt(void); -static void dump_blkd_tasks(struct rcu_node *rnp, int ncheck); +static void dump_blkd_tasks(struct rcu_state *rsp, struct rcu_node *rnp, + int ncheck); static void rcu_initiate_boost(struct rcu_node *rnp, unsigned long flags); static void rcu_preempt_boost_start_gp(struct rcu_node *rnp); static void invoke_rcu_callbacks_kthread(void); |