From 37f58ad6bff2bf2bac4f3f20c2684e8cee66af03 Mon Sep 17 00:00:00 2001 From: Rickard Green Date: Tue, 15 Dec 2015 09:40:30 +0100 Subject: Light weight statistics of run queue lengths - statistics(total_run_queue_lengths) - statistics(run_queue_lengths) - statistics(total_active_tasks) - statistics(active_tasks) Conflicts: erts/emulator/beam/erl_process.c --- erts/doc/src/erlang.xml | 111 ++++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 99 insertions(+), 12 deletions(-) (limited to 'erts/doc') diff --git a/erts/doc/src/erlang.xml b/erts/doc/src/erlang.xml index c37ed3bea5..64eebec936 100644 --- a/erts/doc/src/erlang.xml +++ b/erts/doc/src/erlang.xml @@ -5684,8 +5684,31 @@ true Dest, Msg, []).

+ + Information about active processes and ports. + +

+ Returns a list where each element represents the amount + of active processes and ports on each run queue and its + associated scheduler. That is, the number of processes and + ports that are ready to run, or are currently running. The + element location in the list corresponds to the scheduler + and its run queue. The first element corresponds to scheduler + number 1 and so on. The information is not gathered + atomically. That is, the result is not necessarily a + consistent snapshot of the state, but instead quite + efficiently gathered. See also, + statistics(total_active_tasks), + statistics(run_queue_lengths), and + statistics(total_run_queue_lengths). +

+
+
+ + + Information about context switches.

Returns the total number of context switches since the @@ -5694,7 +5717,7 @@ true - + Information about exact reductions. @@ -5708,7 +5731,7 @@ true - + Information about garbage collection.

Returns information about garbage collection, for example:

@@ -5720,7 +5743,7 @@ true
- + Information about I/O.

Returns Input, @@ -5731,7 +5754,7 @@ true - + Information about reductions. @@ -5749,16 +5772,43 @@ true - - Information about the run-queue. - -

Returns the total length of run-queues, that is, the number - of processes that are ready to run on all available run-queues.

+ + Information about the run-queues. + +

+ Returns the total length of the run-queues. That is, the number + of processes and ports that are ready to run on all available + run-queues. The information is gathered atomically. That + is, the result is a consistent snapshot of the state, but + this operation is much more expensive compared to + statistics(total_run_queue_lengths). + This especially when a large amount of schedulers is used. +

- + + Information about the run-queue lengths. + +

+ Returns a list where each element represents the amount + of processes and ports ready to run for each run queue. The + element location in the list corresponds to the run queue + of a scheduler. The first element corresponds to the run + queue of scheduler number 1 and so on. The information is + not gathered atomically. That is, the result is + not necessarily a consistent snapshot of the state, but + instead quite efficiently gathered. See also, + statistics(total_run_queue_lengths), + statistics(active_tasks), and + statistics(total_active_tasks). +

+
+
+ + + Information about runtime.

Returns information about runtime, in milliseconds.

@@ -5773,7 +5823,7 @@ true
- + Information about each schedulers work time. @@ -5844,7 +5894,44 @@ ok - + + Information about active processes and ports. + +

+ Returns the total amount of active processes and ports in + the system. That is, the number of processes and ports that + are ready to run, or are currently running. The information + is not gathered atomically. That is, the result + is not necessarily a consistent snapshot of the state, but + instead quite efficiently gathered. See also, + statistics(active_tasks), + statistics(run_queue_lengths), and + statistics(total_run_queue_lengths). +

+
+
+ + + + Information about the run-queue lengths. + +

+ Returns the total length of the run-queues. That is, the number + of processes and ports that are ready to run on all available + run-queues. The information is not gathered atomically. + That is, the result is not necessarily a consistent snapshot of + the state, but much more efficiently gathered compared to + statistics(run_queue). + See also, + statistics(run_queue_lengths), + statistics(total_active_tasks), and + statistics(active_tasks). +

+
+
+ + + Information about wall clock.

Returns information about wall clock. wall_clock can -- cgit v1.2.3