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| author | Paul E. McKenney <paulmck@linux.ibm.com> | 2018-10-02 12:42:21 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.ibm.com> | 2018-11-12 09:03:59 -0800 |
| commit | c669c014d1dae9c7cdbfff049c798722f8650829 (patch) | |
| tree | 024c630b4ce3c6cff6bee340a43ce52fb15d9d28 /kernel/rcu/tree.c | |
| parent | 691960197e8daa39bf89886ba2e39de1e33f1ce4 (diff) | |
| download | lwn-c669c014d1dae9c7cdbfff049c798722f8650829.tar.gz lwn-c669c014d1dae9c7cdbfff049c798722f8650829.zip | |
rcu: Add jiffies-since-GP-activity to show_rcu_gp_kthreads()
This commit adds a printout of the number of jiffies since the last time
that the RCU grace-period kthread did any processing. This can be useful
when tracking down forward-progress issues.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Diffstat (limited to 'kernel/rcu/tree.c')
| -rw-r--r-- | kernel/rcu/tree.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index ea78532183ac..e7c9848d1e1b 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -515,12 +515,14 @@ static const char *gp_state_getname(short gs) void show_rcu_gp_kthreads(void) { int cpu; + unsigned long j; struct rcu_data *rdp; struct rcu_node *rnp; - pr_info("%s: wait state: %s(%d) ->state: %#lx\n", rcu_state.name, - gp_state_getname(rcu_state.gp_state), rcu_state.gp_state, - rcu_state.gp_kthread->state); + j = jiffies - READ_ONCE(rcu_state.gp_activity); + pr_info("%s: wait state: %s(%d) ->state: %#lx delta ->gp_activity %ld\n", + rcu_state.name, gp_state_getname(rcu_state.gp_state), + rcu_state.gp_state, rcu_state.gp_kthread->state, j); rcu_for_each_node_breadth_first(rnp) { if (ULONG_CMP_GE(rcu_state.gp_seq, rnp->gp_seq_needed)) continue; |