[PATCH] add success/failure indication to RCU torture test

One issue with the RCU torture test is that the current error flagging can
be lost in dmesg.  This patch adds a "SUCCESS"/"FAILURE" string to the line
that flags the end of the test, where it can easily be seen with "dmesg |
tail" at the end of the test.  Also adds tests of architecture-specific
memory barriers -- or, more likely, of the RCU torture test itself.

Cc: <vatsa@in.ibm.com>
Signed-off-by: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c
index eb6719c50b4e0deb4546e7479a42bb82a9db90e4..88c28d476550d004fe3232ab284d54473f5885a9 100644 (file)
--- a/kernel/rcutorture.c
+++ b/kernel/rcutorture.c
@@ -80,6 +80,7 @@ struct rcu_torture {
        struct rcu_head rtort_rcu;
        int rtort_pipe_count;
        struct list_head rtort_free;
+       int rtort_mbtest;
 };
 
 static int fullstop = 0;       /* stop generating callbacks at test end. */
@@ -96,6 +97,8 @@ static atomic_t rcu_torture_wcount[RCU_TORTURE_PIPE_LEN + 1];
 atomic_t n_rcu_torture_alloc;
 atomic_t n_rcu_torture_alloc_fail;
 atomic_t n_rcu_torture_free;
+atomic_t n_rcu_torture_mberror;
+atomic_t n_rcu_torture_error;
 
 /*
  * Allocate an element from the rcu_tortures pool.
@@ -145,9 +148,10 @@ rcu_torture_cb(struct rcu_head *p)
        if (i > RCU_TORTURE_PIPE_LEN)
                i = RCU_TORTURE_PIPE_LEN;
        atomic_inc(&rcu_torture_wcount[i]);
-       if (++rp->rtort_pipe_count >= RCU_TORTURE_PIPE_LEN)
+       if (++rp->rtort_pipe_count >= RCU_TORTURE_PIPE_LEN) {
+               rp->rtort_mbtest = 0;
                rcu_torture_free(rp);
-       else
+       } else
                call_rcu(p, rcu_torture_cb);
 }
 
@@ -206,6 +210,7 @@ rcu_torture_writer(void *arg)
                rp->rtort_pipe_count = 0;
                udelay(rcu_random(&rand) & 0x3ff);
                old_rp = rcu_torture_current;
+               rp->rtort_mbtest = 1;
                rcu_assign_pointer(rcu_torture_current, rp);
                smp_wmb();
                if (old_rp != NULL) {
@@ -252,6 +257,8 @@ rcu_torture_reader(void *arg)
                        schedule_timeout_interruptible(HZ);
                        continue;
                }
+               if (p->rtort_mbtest == 0)
+                       atomic_inc(&n_rcu_torture_mberror);
                udelay(rcu_random(&rand) & 0x7f);
                preempt_disable();
                pipe_count = p->rtort_pipe_count;
@@ -300,16 +307,22 @@ rcu_torture_printk(char *page)
        }
        cnt += sprintf(&page[cnt], "rcutorture: ");
        cnt += sprintf(&page[cnt],
-                      "rtc: %p ver: %ld tfle: %d rta: %d rtaf: %d rtf: %d",
+                      "rtc: %p ver: %ld tfle: %d rta: %d rtaf: %d rtf: %d "
+                      "rtmbe: %d",
                       rcu_torture_current,
                       rcu_torture_current_version,
                       list_empty(&rcu_torture_freelist),
                       atomic_read(&n_rcu_torture_alloc),
                       atomic_read(&n_rcu_torture_alloc_fail),
-                      atomic_read(&n_rcu_torture_free));
+                      atomic_read(&n_rcu_torture_free),
+                      atomic_read(&n_rcu_torture_mberror));
+       if (atomic_read(&n_rcu_torture_mberror) != 0)
+               cnt += sprintf(&page[cnt], " !!!");
        cnt += sprintf(&page[cnt], "\nrcutorture: ");
-       if (i > 1)
+       if (i > 1) {
                cnt += sprintf(&page[cnt], "!!! ");
+               atomic_inc(&n_rcu_torture_error);
+       }
        cnt += sprintf(&page[cnt], "Reader Pipe: ");
        for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++)
                cnt += sprintf(&page[cnt], " %ld", pipesummary[i]);
@@ -400,7 +413,9 @@ rcu_torture_cleanup(void)
        for (i = 0; i < RCU_TORTURE_PIPE_LEN; i++)
                synchronize_rcu();
        rcu_torture_stats_print();  /* -After- the stats thread is stopped! */
-       PRINTK_STRING("--- End of test");
+       printk(KERN_ALERT TORTURE_FLAG
+              "--- End of test: %s\n",
+              atomic_read(&n_rcu_torture_error) == 0 ? "SUCCESS" : "FAILURE");
 }
 
 static int
@@ -425,6 +440,7 @@ rcu_torture_init(void)
 
        INIT_LIST_HEAD(&rcu_torture_freelist);
        for (i = 0; i < sizeof(rcu_tortures) / sizeof(rcu_tortures[0]); i++) {
+               rcu_tortures[i].rtort_mbtest = 0;
                list_add_tail(&rcu_tortures[i].rtort_free,
                              &rcu_torture_freelist);
        }
@@ -436,6 +452,8 @@ rcu_torture_init(void)
        atomic_set(&n_rcu_torture_alloc, 0);
        atomic_set(&n_rcu_torture_alloc_fail, 0);
        atomic_set(&n_rcu_torture_free, 0);
+       atomic_set(&n_rcu_torture_mberror, 0);
+       atomic_set(&n_rcu_torture_error, 0);
        for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++)
                atomic_set(&rcu_torture_wcount[i], 0);
        for_each_cpu(cpu) {