MINOR: activity: report the number of times poll() reports I/O
The "show activity" output mentions a number of indicators to explain
wake up reasons but doesn't have the number of times poll() sees some
I/O. And given that multiple events can happen simultaneously, it's
not always possible to deduce this metric by subtracting.
This patch adds a new "poll_io" counter that allows one to see how
often poll() returns with at least one active FD. This should help
detect stuck events and measure various ratios of poll sub-metrics.
diff --git a/src/ev_evports.c b/src/ev_evports.c
index 6b14ea0..50d9a1e 100644
--- a/src/ev_evports.c
+++ b/src/ev_evports.c
@@ -207,6 +207,9 @@
thread_harmless_end();
+ if (nevlist > 0)
+ activity[tid].poll_io++;
+
for (i = 0; i < nevlist; i++) {
unsigned int n = 0;
int events, rebind_events;