diff options
Diffstat (limited to 'erts/doc/src/erlang.xml')
| -rw-r--r-- | erts/doc/src/erlang.xml | 99 |
1 files changed, 71 insertions, 28 deletions
diff --git a/erts/doc/src/erlang.xml b/erts/doc/src/erlang.xml index 1f8e89768c..350a8506f5 100644 --- a/erts/doc/src/erlang.xml +++ b/erts/doc/src/erlang.xml @@ -6469,32 +6469,44 @@ ok <p><marker id="system_flag_multi_scheduling"></marker> If multi-scheduling is enabled, more than one scheduler thread is used by the emulator. Multi-scheduling can be - blocked. When multi-scheduling is blocked, only - one scheduler thread schedules Erlang processes.</p> + blocked in two different ways. Either all schedulers but + one is blocked, or all <em>normal</em> schedulers but + one is blocked. When only normal schedulers are blocked + dirty schedulers are free to continue to schedule + processes.</p> <p>If <c><anno>BlockState</anno> =:= block</c>, multi-scheduling is - blocked. If <c><anno>BlockState</anno> =:= unblock</c> and no one + blocked. That is, one and only one scheduler thread will + execute. If <c><anno>BlockState</anno> =:= unblock</c> and no one else blocks multi-scheduling, and this process has blocked only once, multi-scheduling is unblocked.</p> - <p>One process can block multi-scheduling multiple times. - If a process has blocked multiple times, it must - unblock exactly as many times as it has blocked before it - has released its multi-scheduling block. If a process that - has blocked multi-scheduling exits, it releases its - blocking of multi-scheduling.</p> + <p>If <c><anno>BlockState</anno> =:= block_normal</c>, normal + multi-scheduling is blocked. That is, only one normal scheduler + thread will execute, but multiple dirty schedulers may execute. + If <c><anno>BlockState</anno> =:= unblock_normal</c> and no one + else blocks normal multi-scheduling, and this process has + blocked only once, normal multi-scheduling is unblocked.</p> + <p>One process can block multi-scheduling as well as normal + multi-scheduling multiple times. If a process has blocked + multiple times, it must unblock exactly as many times as it + has blocked before it has released its multi-scheduling + block. If a process that has blocked multi-scheduling or normal + multi scheduling exits, it automatically releases its blocking + of multi-scheduling and normal multi-scheduling.</p> <p>The return values are <c>disabled</c>, <c>blocked</c>, - or <c>enabled</c>. The returned value describes the - state just after the call to + <c>blocked_normal</c>, or <c>enabled</c>. The returned value + describes the state just after the call to <c>erlang:system_flag(multi_scheduling, <anno>BlockState</anno>)</c> has been made. For information about the return values, see <seealso marker="#system_info_multi_scheduling">erlang:system_info(multi_scheduling)</seealso>.</p> - <note><p>Blocking of multi-scheduling is normally not needed. - If you feel that you need to block multi-scheduling, - consider it a few more times again. Blocking multi-scheduling - is only to be used as a last resort, as it is most likely - a <em>very inefficient</em> way to solve the problem.</p> + <note><p>Blocking of multi-scheduling and normal multi-scheduling + is normally not needed. If you feel that you need to use these + features, consider it a few more times again. Blocking + multi-scheduling is only to be used as a last resort, as it is + most likely a <em>very inefficient</em> way to solve the problem.</p> </note> <p>See also <seealso marker="#system_info_multi_scheduling">erlang:system_info(multi_scheduling)</seealso>, + <seealso marker="#system_info_normal_multi_scheduling_blockers">erlang:system_info(normal_multi_scheduling_blockers)</seealso>, <seealso marker="#system_info_multi_scheduling_blockers">erlang:system_info(multi_scheduling_blockers)</seealso>, and <seealso marker="#system_info_schedulers">erlang:system_info(schedulers)</seealso>.</p> </desc> @@ -7329,6 +7341,16 @@ ok where <c><anno>MinHeapSize</anno></c> is the current system-wide minimum heap size for spawned processes.</p> </item> + <tag><marker id="system_info_message_queue_data"><c>message_queue_data</c></marker></tag> + <item> + <p>Returns the default value of the <c>message_queue_data</c> + process flag which is either <c>off_heap</c>, <c>on_heap</c>, or <c>mixed</c>. + This default is set by the <c>erl</c> command line argument + <seealso marker="erl#+xmqd"><c>+xmqd</c></seealso>. For more information on the + <c>message_queue_data</c> process flag, see documentation of + <seealso marker="#process_flag_message_queue_data"><c>process_flag(message_queue_data, + MQD)</c></seealso>.</p> + </item> <tag><c>min_bin_vheap_size</c></tag> <item> <p>Returns <c>{min_bin_vheap_size, @@ -7348,7 +7370,8 @@ ok <tag><c>multi_scheduling</c></tag> <item> <marker id="system_info_multi_scheduling"></marker> - <p>Returns <c>disabled</c>, <c>blocked</c>, or <c>enabled</c>:</p> + <p>Returns <c>disabled</c>, <c>blocked</c>, <c>blocked_normal</c>, + or <c>enabled</c>:</p> <taglist> <tag><c>disabled</c></tag> <item> @@ -7359,14 +7382,22 @@ ok <tag><c>blocked</c></tag> <item> <p>The emulator has more than one scheduler thread, - but all scheduler threads except one are blocked, - that is, only one scheduler thread schedules + but all scheduler threads except one are blocked. + That is, only one scheduler thread schedules Erlang processes and executes Erlang code.</p> </item> + <tag><c>blocked_normal</c></tag> + <item> + <p>The emulator has more than one scheduler thread, + but all normal scheduler threads except one are + blocked. Note that dirty schedulers are not + blocked, and may schedule Erlang processes and + execute native code.</p> + </item> <tag><c>enabled</c></tag> <item> <p>The emulator has more than one scheduler thread, - and no scheduler threads are blocked, that is, + and no scheduler threads are blocked. That is, all available scheduler threads schedule Erlang processes and execute Erlang code.</p> </item> @@ -7374,6 +7405,7 @@ ok <p>See also <seealso marker="#system_flag_multi_scheduling">erlang:system_flag(multi_scheduling, BlockState)</seealso>, <seealso marker="#system_info_multi_scheduling_blockers">erlang:system_info(multi_scheduling_blockers)</seealso>, + <seealso marker="#system_info_normal_multi_scheduling_blockers">erlang:system_info(normal_multi_scheduling_blockers)</seealso>, and <seealso marker="#system_info_schedulers">erlang:system_info(schedulers)</seealso>.</p> </item> @@ -7390,6 +7422,8 @@ ok <p>See also <seealso marker="#system_flag_multi_scheduling">erlang:system_flag(multi_scheduling, BlockState)</seealso>, <seealso marker="#system_info_multi_scheduling">erlang:system_info(multi_scheduling)</seealso>, + <seealso marker="#system_info_normal_multi_scheduling_blockers">erlang:system_info(normal_multi_scheduling_blockers)</seealso>, + and <seealso marker="#system_info_schedulers">erlang:system_info(schedulers)</seealso>.</p> </item> @@ -7399,15 +7433,23 @@ ok used by the runtime system. It is on the form "<major ver>.<minor ver>".</p> </item> - <tag><marker id="system_info_message_queue_data"><c>message_queue_data</c></marker></tag> + <tag><c>normal_multi_scheduling_blockers</c></tag> <item> - <p>Returns the default value of the <c>message_queue_data</c> - process flag which is either <c>off_heap</c>, <c>on_heap</c>, or <c>mixed</c>. - This default is set by the <c>erl</c> command line argument - <seealso marker="erl#+xmqd"><c>+xmqd</c></seealso>. For more information on the - <c>message_queue_data</c> process flag, see documentation of - <seealso marker="#process_flag_message_queue_data"><c>process_flag(message_queue_data, - MQD)</c></seealso>.</p> + <marker id="system_info_normal_multi_scheduling_blockers"></marker> + <p>Returns a list of <c><anno>Pid</anno></c>s when + normal multi-scheduling is blocked (i.e. all normal schedulers + but one is blocked), otherwise the empty list is returned. + The <c><anno>Pid</anno></c>s in the list represent all the + processes currently blocking normal multi-scheduling. + A <c><anno>Pid</anno></c> occurs only once in the list, even if + the corresponding process has blocked multiple times.</p> + <p>See also + <seealso marker="#system_flag_multi_scheduling">erlang:system_flag(multi_scheduling, BlockState)</seealso>, + <seealso marker="#system_info_multi_scheduling">erlang:system_info(multi_scheduling)</seealso>, + <seealso marker="#system_info_multi_scheduling_blockers">erlang:system_info(multi_scheduling_blockers)</seealso>, + + and + <seealso marker="#system_info_schedulers">erlang:system_info(schedulers)</seealso>.</p> </item> <tag><marker id="system_info_otp_release"><c>otp_release</c></marker></tag> <item> @@ -7650,6 +7692,7 @@ ok <seealso marker="#system_info_scheduler_id">erlang:system_info(scheduler_id)</seealso>, <seealso marker="#system_flag_multi_scheduling">erlang:system_flag(multi_scheduling, BlockState)</seealso>, <seealso marker="#system_info_multi_scheduling">erlang:system_info(multi_scheduling)</seealso>, + <seealso marker="#system_info_normal_multi_scheduling_blockers">erlang:system_info(normal_multi_scheduling_blockers)</seealso> and <seealso marker="#system_info_multi_scheduling_blockers">erlang:system_info(multi_scheduling_blockers)</seealso>.</p> </item> |