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-rw-r--r--erts/doc/src/erlang.xml99
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
"&lt;major ver&gt;.&lt;minor ver&gt;".</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>