poll-loop: Log backtraces when CPU usage is high.

[openvswitch] / lib / poll-loop.c

diff --git a/lib/poll-loop.c b/lib/poll-loop.c
index 516cf13d1db321925a80c71dfd63de6bfd1de646..7e328bc24ce486b2243cdfce1929c5464f513b02 100644 (file)
--- a/lib/poll-loop.c
+++ b/lib/poll-loop.c
@@ -157,6 +157,7 @@ poll_immediate_wake(const char *where)
 static void
 log_wakeup(const char *where, const struct pollfd *pollfd, int timeout)
 {
+    static struct vlog_rate_limit trace_rl = VLOG_RATE_LIMIT_INIT(1, 1);
     static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(10, 10);
     enum vlog_level level;
     int cpu_usage;
@@ -200,6 +201,11 @@ log_wakeup(const char *where, const struct pollfd *pollfd, int timeout)
     }
     if (cpu_usage >= 0) {
         ds_put_format(&s, " (%d%% CPU usage)", cpu_usage);
+
+        if (!vlog_should_drop(THIS_MODULE, level, &trace_rl)) {
+            ds_put_char(&s, '\n');
+            format_backtraces(&s, 2);
+        }
     }
     VLOG(level, "%s", ds_cstr(&s));
     ds_destroy(&s);