rcu: Reduce rcutorture tracing

[mirror_ubuntu-artful-kernel.git] / kernel / rcutorture.c

diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c
index 31dea01c85fd50fb3297627dc81556a146f249c5..a583f1ce713dfcb9ae5ede5502efd4241655e328 100644 (file)
--- a/kernel/rcutorture.c
+++ b/kernel/rcutorture.c
@@ -46,6 +46,7 @@
 #include <linux/stat.h>
 #include <linux/srcu.h>
 #include <linux/slab.h>
+#include <linux/trace_clock.h>
 #include <asm/byteorder.h>
 
 MODULE_LICENSE("GPL");
@@ -1028,7 +1029,6 @@ void rcutorture_trace_dump(void)
                return;
        if (atomic_xchg(&beenhere, 1) != 0)
                return;
-       do_trace_rcu_torture_read(cur_ops->name, (struct rcu_head *)~0UL);
        ftrace_dump(DUMP_ALL);
 }
 
@@ -1042,13 +1042,16 @@ static void rcu_torture_timer(unsigned long unused)
 {
        int idx;
        int completed;
+       int completed_end;
        static DEFINE_RCU_RANDOM(rand);
        static DEFINE_SPINLOCK(rand_lock);
        struct rcu_torture *p;
        int pipe_count;
+       unsigned long long ts;
 
        idx = cur_ops->readlock();
        completed = cur_ops->completed();
+       ts = trace_clock_local();
        p = rcu_dereference_check(rcu_torture_current,
                                  rcu_read_lock_bh_held() ||
                                  rcu_read_lock_sched_held() ||
@@ -1058,7 +1061,6 @@ static void rcu_torture_timer(unsigned long unused)
                cur_ops->readunlock(idx);
                return;
        }
-       do_trace_rcu_torture_read(cur_ops->name, &p->rtort_rcu);
        if (p->rtort_mbtest == 0)
                atomic_inc(&n_rcu_torture_mberror);
        spin_lock(&rand_lock);
@@ -1071,10 +1073,16 @@ static void rcu_torture_timer(unsigned long unused)
                /* Should not happen, but... */
                pipe_count = RCU_TORTURE_PIPE_LEN;
        }
-       if (pipe_count > 1)
+       completed_end = cur_ops->completed();
+       if (pipe_count > 1) {
+               unsigned long __maybe_unused ts_rem = do_div(ts, NSEC_PER_USEC);
+
+               do_trace_rcu_torture_read(cur_ops->name, &p->rtort_rcu, ts,
+                                         completed, completed_end);
                rcutorture_trace_dump();
+       }
        __this_cpu_inc(rcu_torture_count[pipe_count]);
-       completed = cur_ops->completed() - completed;
+       completed = completed_end - completed;
        if (completed > RCU_TORTURE_PIPE_LEN) {
                /* Should not happen, but... */
                completed = RCU_TORTURE_PIPE_LEN;
@@ -1094,11 +1102,13 @@ static int
 rcu_torture_reader(void *arg)
 {
        int completed;
+       int completed_end;
        int idx;
        DEFINE_RCU_RANDOM(rand);
        struct rcu_torture *p;
        int pipe_count;
        struct timer_list t;
+       unsigned long long ts;
 
        VERBOSE_PRINTK_STRING("rcu_torture_reader task started");
        set_user_nice(current, 19);
@@ -1112,6 +1122,7 @@ rcu_torture_reader(void *arg)
                }
                idx = cur_ops->readlock();
                completed = cur_ops->completed();
+               ts = trace_clock_local();
                p = rcu_dereference_check(rcu_torture_current,
                                          rcu_read_lock_bh_held() ||
                                          rcu_read_lock_sched_held() ||
@@ -1122,7 +1133,6 @@ rcu_torture_reader(void *arg)
                        schedule_timeout_interruptible(HZ);
                        continue;
                }
-               do_trace_rcu_torture_read(cur_ops->name, &p->rtort_rcu);
                if (p->rtort_mbtest == 0)
                        atomic_inc(&n_rcu_torture_mberror);
                cur_ops->read_delay(&rand);
@@ -1132,10 +1142,17 @@ rcu_torture_reader(void *arg)
                        /* Should not happen, but... */
                        pipe_count = RCU_TORTURE_PIPE_LEN;
                }
-               if (pipe_count > 1)
+               completed_end = cur_ops->completed();
+               if (pipe_count > 1) {
+                       unsigned long __maybe_unused ts_rem =
+                                       do_div(ts, NSEC_PER_USEC);
+
+                       do_trace_rcu_torture_read(cur_ops->name, &p->rtort_rcu,
+                                                 ts, completed, completed_end);
                        rcutorture_trace_dump();
+               }
                __this_cpu_inc(rcu_torture_count[pipe_count]);
-               completed = cur_ops->completed() - completed;
+               completed = completed_end - completed;
                if (completed > RCU_TORTURE_PIPE_LEN) {
                        /* Should not happen, but... */
                        completed = RCU_TORTURE_PIPE_LEN;