MINOR: global: add some global activity counters to help debugging
A number of counters have been added at special places helping better
understanding certain bug reports. These counters are maintained per
thread and are shown using "show activity" on the CLI. The "clear
counters" commands also reset these counters. The output is sent as a
single write(), which currently produces up to about 7 kB of data for
64 threads. If more counters are added, it may be necessary to write
into multiple buffers, or to reset the counters.
To backport to 1.8 to help collect more detailed bug reports.
diff --git a/include/types/global.h b/include/types/global.h
index 5c5cf73..bd7761c 100644
--- a/include/types/global.h
+++ b/include/types/global.h
@@ -173,7 +173,34 @@
#endif
};
+/* per-thread activity reports. It's important that it's aligned on cache lines
+ * because some elements will be updated very often. Most counters are OK on
+ * 32-bit since this will be used during debugging sessions for troubleshooting
+ * in iterative mode.
+ */
+struct activity {
+ unsigned int loops; // complete loops in run_poll_loop()
+ unsigned int wake_cache; // active fd_cache prevented poll() from sleeping
+ unsigned int wake_tasks; // active tasks prevented poll() from sleeping
+ unsigned int wake_applets; // active applets prevented poll() from sleeping
+ unsigned int wake_signal; // pending signal prevented poll() from sleeping
+ unsigned int poll_exp; // number of times poll() sees an expired timeout (includes wake_*)
+ unsigned int poll_drop; // poller dropped a dead FD from the update list
+ unsigned int poll_dead; // poller woke up with a dead FD
+ unsigned int poll_skip; // poller skipped another thread's FD
+ unsigned int fd_skip; // fd cache skipped another thread's FD
+ unsigned int fd_lock; // fd cache skipped a locked FD
+ unsigned int fd_del; // fd cache detected a deleted FD
+ unsigned int conn_dead; // conn_fd_handler woke up on an FD indicating a dead connection
+ unsigned int stream; // calls to process_stream()
+ unsigned int empty_rq; // calls to process_runnable_tasks() with nothing for the thread
+ unsigned int long_rq; // process_runnable_tasks() left with tasks in the run queue
+ char __pad[0]; // unused except to check remaining room
+ char __end[0] __attribute__((aligned(64))); // align size to 64.
+};
+
extern struct global global;
+extern struct activity activity[MAX_THREADS];
extern int pid; /* current process id */
extern int relative_pid; /* process id starting at 1 */
extern unsigned long pid_bit; /* bit corresponding to the process id */