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authorPaul E. McKenney <paulmck@linux.ibm.com>2018-10-02 17:09:56 -0700
committerPaul E. McKenney <paulmck@linux.ibm.com>2018-12-01 12:45:38 -0800
commitbfcfcffc5f23e76a1b88f7412ee7efaec5107b28 (patch)
tree3945bad0d3b2bc85cf31f08aae6e3a53949a7efd
parent903ee83d91776bc72d856147743687d4b6c99286 (diff)
rcu: Print per-CPU callback counts for forward-progress failures
This commit prints out the non-zero per-CPU callback counts when a forware-progress error (OOM event) occurs. Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com> [ paulmck: Fix a pair of uninitialized locals spotted by kbuild test robot. ]
-rw-r--r--kernel/rcu/tree.c18
1 files changed, 18 insertions, 0 deletions
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 0933d8650890..90a67c75a447 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -2675,6 +2675,10 @@ rcu_check_gp_start_stall(struct rcu_node *rnp, struct rcu_data *rdp,
*/
void rcu_fwd_progress_check(unsigned long j)
{
+ unsigned long cbs;
+ int cpu;
+ unsigned long max_cbs = 0;
+ int max_cpu = -1;
struct rcu_data *rdp;
if (rcu_gp_in_progress()) {
@@ -2685,6 +2689,20 @@ void rcu_fwd_progress_check(unsigned long j)
rcu_check_gp_start_stall(rdp->mynode, rdp, j);
preempt_enable();
}
+ for_each_possible_cpu(cpu) {
+ cbs = rcu_get_n_cbs_cpu(cpu);
+ if (!cbs)
+ continue;
+ if (max_cpu < 0)
+ pr_info("%s: callbacks", __func__);
+ pr_cont(" %d: %lu", cpu, cbs);
+ if (cbs <= max_cbs)
+ continue;
+ max_cbs = cbs;
+ max_cpu = cpu;
+ }
+ if (max_cpu >= 0)
+ pr_cont("\n");
}
EXPORT_SYMBOL_GPL(rcu_fwd_progress_check);