Provide ability to retrieve coverage information

Previously, there was no way to induce coverage information to be
displayed; it would only print when the system noticed unusual delays
between polling intervals.  Now, production of coverage logs can be
forced with "coverage/log" command in ovs-appctl.  Coverage counters may
be reset with "coverage/clear".

diff --git a/lib/coverage.c b/lib/coverage.c
index eaa441c..e86aa02 100644 (file)
--- a/lib/coverage.c
+++ b/lib/coverage.c
@@ -21,6 +21,7 @@
 #include "coverage-counters.h"
 #include "dynamic-string.h"
 #include "hash.h"
+#include "unixctl.h"
 #include "util.h"
 
 #define THIS_MODULE VLM_coverage
@@ -28,6 +29,27 @@
 
 static unsigned int epoch;
 
+static void
+coverage_unixctl_log(struct unixctl_conn *conn, const char *args UNUSED)
+{
+    coverage_log(VLL_WARN, false);
+    unixctl_command_reply(conn, 200, NULL);
+}
+
+static void
+coverage_unixctl_clear(struct unixctl_conn *conn, const char *args UNUSED)
+{
+    coverage_clear();
+    unixctl_command_reply(conn, 200, NULL);
+}
+
+void
+coverage_init(void)
+{
+    unixctl_command_register("coverage/log", coverage_unixctl_log);
+    unixctl_command_register("coverage/clear", coverage_unixctl_clear);
+}
+
 /* Sorts coverage counters in descending order by count, within equal counts
  * alphabetically by name. */
 static int
@@ -107,9 +129,10 @@ coverage_log_counter(enum vlog_level level, const struct coverage_counter *c)
     VLOG(level, "%-24s %5u / %9llu", c->name, c->count, c->count + c->total);
 }
 
-/* Logs the coverage counters at the given vlog 'level'. */
+/* Logs the coverage counters at the given vlog 'level'.  If
+ * 'suppress_dups' is true, then duplicate events are not displayed. */
 void
-coverage_log(enum vlog_level level)
+coverage_log(enum vlog_level level, bool suppress_dups)
 {
     size_t n_never_hit;
     uint32_t hash;
@@ -119,11 +142,13 @@ coverage_log(enum vlog_level level)
         return;
     }
 
-    hash = coverage_hash();
-    if (coverage_hit(hash)) {
-        VLOG(level, "Skipping details of duplicate event coverage for "
-             "hash=%08"PRIx32" in epoch %u", hash, epoch);
-        return;
+    if (suppress_dups) {
+        hash = coverage_hash();
+        if (coverage_hit(hash)) {
+            VLOG(level, "Skipping details of duplicate event coverage for "
+                 "hash=%08"PRIx32" in epoch %u", hash, epoch);
+            return;
+        }
     }
 
     n_never_hit = 0;

diff --git a/lib/coverage.h b/lib/coverage.h
index f5ae990..aa93630 100644 (file)
--- a/lib/coverage.h
+++ b/lib/coverage.h
@@ -52,7 +52,8 @@ struct coverage_counter {
         NAME##_count.count += AMOUNT;                   \
     } while (0)
 
-void coverage_log(enum vlog_level);
+void coverage_init(void);
+void coverage_log(enum vlog_level, bool suppress_dups);
 void coverage_clear(void);
 
 #endif /* coverage.h */

diff --git a/lib/timeval.c b/lib/timeval.c
index 61f2227..4c34a17 100644 (file)
--- a/lib/timeval.c
+++ b/lib/timeval.c
@@ -63,6 +63,8 @@ time_init(void)
         return;
     }
 
+    coverage_init();
+
     inited = true;
     gettimeofday(&now, NULL);
     tick = false;
@@ -292,7 +294,7 @@ log_poll_interval(long long int last_wakeup, const struct rusage *last_rusage)
                       rusage.ru_nvcsw - last_rusage->ru_nvcsw,
                       rusage.ru_nivcsw - last_rusage->ru_nivcsw);
         }
-        coverage_log(VLL_WARN);
+        coverage_log(VLL_WARN, true);
     }
 
     /* Update exponentially weighted moving average.  With these parameters, a