srcu: Add address of first callback to rcutorture output

This commit adds the address of the first callback to the per-CPU rcutorture
output in order to allow lost wakeups to be more efficiently tracked down.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c
index 37bef2f..5a1a9a0 100644 (file)
--- a/kernel/rcu/srcutree.c
+++ b/kernel/rcu/srcutree.c
@@ -1271,11 +1271,11 @@ void srcu_torture_stats_print(struct srcu_struct *sp, char *tt, char *tf)
                unsigned long l0, l1;
                unsigned long u0, u1;
                long c0, c1;
-               struct srcu_data *counts;
+               struct srcu_data *sdp;
 
-               counts = per_cpu_ptr(sp->sda, cpu);
-               u0 = counts->srcu_unlock_count[!idx];
-               u1 = counts->srcu_unlock_count[idx];
+               sdp = per_cpu_ptr(sp->sda, cpu);
+               u0 = sdp->srcu_unlock_count[!idx];
+               u1 = sdp->srcu_unlock_count[idx];
 
                /*
                 * Make sure that a lock is always counted if the corresponding
@@ -1283,12 +1283,13 @@ void srcu_torture_stats_print(struct srcu_struct *sp, char *tt, char *tf)
                 */
                smp_rmb();
 
-               l0 = counts->srcu_lock_count[!idx];
-               l1 = counts->srcu_lock_count[idx];
+               l0 = sdp->srcu_lock_count[!idx];
+               l1 = sdp->srcu_lock_count[idx];
 
                c0 = l0 - u0;
                c1 = l1 - u1;
-               pr_cont(" %d(%ld,%ld)", cpu, c0, c1);
+               pr_cont(" %d(%ld,%ld %1p)",
+                       cpu, c0, c1, rcu_segcblist_head(&sdp->srcu_cblist));
                s0 += c0;
                s1 += c1;
        }