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| author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2015-01-22 14:32:06 -0800 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2015-03-11 13:22:38 -0700 |
| commit | 237a0f2193c6daf9b1edd7fd15d55e680f268952 (patch) | |
| tree | 7f7c0b994878808a47842138a3026620fc2c6edf | |
| parent | 18c629eaebf1814ca7f0c27327f75aa93aa4a5de (diff) | |
| download | lwn-237a0f2193c6daf9b1edd7fd15d55e680f268952.tar.gz lwn-237a0f2193c6daf9b1edd7fd15d55e680f268952.zip | |
rcu: Detect stalls caused by failure to propagate up rcu_node tree
If all CPUs have passed through quiescent states, then stalls might be
due to starvation of the grace-period kthread or to failure to propagate
the quiescent states up the rcu_node combining tree. The current stall
warning messages do not differentiate, so this commit adds a printout
of the root rcu_node structure's ->qsmask field.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| -rw-r--r-- | kernel/rcu/tree.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 98da632d1d49..3b7e4133ca99 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -1196,9 +1196,10 @@ static void print_other_cpu_stall(struct rcu_state *rsp, unsigned long gpnum) } else { j = jiffies; gpa = ACCESS_ONCE(rsp->gp_activity); - pr_err("All QSes seen, last %s kthread activity %ld (%ld-%ld), jiffies_till_next_fqs=%ld\n", + pr_err("All QSes seen, last %s kthread activity %ld (%ld-%ld), jiffies_till_next_fqs=%ld, root ->qsmask %#lx\n", rsp->name, j - gpa, j, gpa, - jiffies_till_next_fqs); + jiffies_till_next_fqs, + rcu_get_root(rsp)->qsmask); /* In this case, the current CPU might be at fault. */ sched_show_task(current); } |