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authorSverker Eriksson <[email protected]>2017-02-03 17:01:52 +0100
committerSverker Eriksson <[email protected]>2017-02-03 17:01:52 +0100
commit69b928b12d9206d00879c08e46143f599f9dc34e (patch)
treefde8905a6ca71c797725a33895321c67e81c3645 /erts/doc/src
parent4b97d656a9e1774fd4ff984014f085ad661a4fdb (diff)
parent1923315e618bea9fb23fc3237541f95a0accc266 (diff)
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Merge branch 'master' into sverker/enif_select
Diffstat (limited to 'erts/doc/src')
-rw-r--r--erts/doc/src/absform.xml2
-rw-r--r--erts/doc/src/erl.xml31
-rw-r--r--erts/doc/src/erl_nif.xml62
-rw-r--r--erts/doc/src/erlang.xml138
-rw-r--r--erts/doc/src/notes.xml173
5 files changed, 328 insertions, 78 deletions
diff --git a/erts/doc/src/absform.xml b/erts/doc/src/absform.xml
index ab00d47425..fe8e3b30e7 100644
--- a/erts/doc/src/absform.xml
+++ b/erts/doc/src/absform.xml
@@ -886,7 +886,7 @@
Rep(Fc) = <c>[Rep(C_1), ..., Rep(C_k)]</c>.</p>
<list type="bulleted">
- <item>If C is a constraint <c>is_subtype(V, T)</c> or <c>V :: T</c>,
+ <item>If C is a constraint <c>V :: T</c>,
where <c>V</c> is a type variable
and <c>T</c> is a type, then Rep(C) =
<c>{type,LINE,constraint,[{atom,LINE,is_subtype},[Rep(V),Rep(T)]]}</c>.
diff --git a/erts/doc/src/erl.xml b/erts/doc/src/erl.xml
index f2a55f6298..4e32118405 100644
--- a/erts/doc/src/erl.xml
+++ b/erts/doc/src/erl.xml
@@ -946,9 +946,7 @@
schedulers was allowed to be unlimited, dirty CPU bound jobs would
potentially starve normal jobs.</p>
<p>This option is ignored if the emulator does not have threading
- support enabled. <em>This option is experimental</em> and
- is supported only if the emulator was configured and built with
- support for dirty schedulers enabled (it is disabled by default).</p>
+ support enabled.</p>
</item>
<tag><marker id="+SDPcpu"/><c><![CDATA[+SDPcpu
DirtyCPUSchedulersPercentage:DirtyCPUSchedulersOnlinePercentage]]></c></tag>
@@ -974,9 +972,7 @@
either order) results in 2 dirty CPU scheduler threads (50% of 4) and
1 dirty CPU scheduler thread online (25% of 4).</p>
<p>This option is ignored if the emulator does not have threading
- support enabled. <em>This option is experimental</em> and
- is supported only if the emulator was configured and built with
- support for dirty schedulers enabled (it is disabled by default).</p>
+ support enabled.</p>
</item>
<tag><marker id="+SDio"/><c><![CDATA[+SDio DirtyIOSchedulers]]></c></tag>
<item>
@@ -992,9 +988,7 @@
bound jobs on dirty I/O schedulers, these jobs might starve ordinary
jobs executing on ordinary schedulers.</p>
<p>This option is ignored if the emulator does not have threading
- support enabled. <em>This option is experimental</em> and
- is supported only if the emulator was configured and built with
- support for dirty schedulers enabled (it is disabled by default).</p>
+ support enabled.</p>
</item>
<tag><c><![CDATA[+sFlag Value]]></c></tag>
<item>
@@ -1595,6 +1589,25 @@
</section>
<section>
+ <marker id="signals"></marker>
+ <title>Signals</title>
+ <p>On Unix systems, the Erlang runtime will interpret two types of signals.</p>
+ <taglist>
+ <tag><c>SIGUSR1</c></tag>
+ <item>
+ <p>A <c>SIGUSR1</c> signal forces a crash dump.</p>
+ </item>
+ <tag><c>SIGTERM</c></tag>
+ <item>
+ <p>A <c>SIGTERM</c> will produce a <c>stop</c> message to the <c>init</c> process.
+ This is equivalent to a <c>init:stop/0</c> call.</p>
+ <p>Introduced in ERTS 8.3 (Erlang/OTP 19.3)</p>
+ </item>
+ </taglist>
+ <p>The signal <c>SIGUSR2</c> is reserved for internal usage. No other signals are handled.</p>
+ </section>
+
+ <section>
<marker id="configuration"></marker>
<title>Configuration</title>
<p>The standard Erlang/OTP system can be reconfigured to change the default
diff --git a/erts/doc/src/erl_nif.xml b/erts/doc/src/erl_nif.xml
index 13b72863f3..8cdfc80879 100644
--- a/erts/doc/src/erl_nif.xml
+++ b/erts/doc/src/erl_nif.xml
@@ -123,7 +123,7 @@ ok
"Hello world!"</code>
<p>A better solution for a real module is to take advantage of the new
- directive <c>on load</c> (see section
+ directive <c>on_load</c> (see section
<seealso marker="doc/reference_manual:code_loading#on_load">Running a
Function When a Module is Loaded</seealso> in the Erlang Reference
Manual) to load the NIF library automatically when the module is
@@ -135,27 +135,14 @@ ok
away by the compiler, causing loading of the NIF library to fail.</p>
</note>
- <p>A loaded NIF library is tied to the Erlang module code version
- that loaded it. If the module is upgraded with a new version, the
- new Erlang code need to load its own NIF library (or maybe choose not
- to). The new code version can, however, choose to load the
- same NIF library as the old code if it wants to. Sharing the
- dynamic library means that static data defined by the library
- is shared as well. To avoid unintentionally shared static
- data, each Erlang module code can keep its own private data. This
- private data can be set when the NIF library is loaded and
- then retrieved by calling <seealso marker="#enif_priv_data">
- <c>enif_priv_data</c></seealso>.</p>
-
- <p>A NIF library cannot be loaded explicitly. A library is
- automatically unloaded when the module code that it belongs to is purged
- by the code server.</p>
+ <p>Once loaded, a NIF library is persistent. It will not be unloaded
+ until the module code version that it belongs to is purged.</p>
</description>
<section>
<title>Functionality</title>
- <p>All functions that a NIF library needs to do with Erlang are
- performed through the NIF API functions. Functions exist
+ <p>All interaction between NIF code and the Erlang runtime system is
+ performed by calling NIF API functions. Functions exist
for the following functionality:</p>
<taglist>
@@ -286,6 +273,19 @@ return term;</code>
library is postponed as long as there exist resource objects with a
destructor function in the library.</p>
</item>
+ <tag>Module upgrade and static data</tag>
+ <item>
+ <p>A loaded NIF library is tied to the Erlang module instance
+ that loaded it. If the module is upgraded, the new module instance
+ needs to load its own NIF library (or maybe choose not to). The new
+ module instance can, however, choose to load the exact same NIF library
+ as the old code if it wants to. Sharing the dynamic library means that
+ static data defined by the library is shared as well. To avoid
+ unintentionally shared static data between module instances, each Erlang
+ module version can keep its own private data. This private data can be
+ set when the NIF library is loaded and later retrieved by calling
+ <seealso marker="#enif_priv_data"><c>enif_priv_data</c></seealso>.</p>
+ </item>
<tag>Threads and concurrency</tag>
<item>
<p>A NIF is thread-safe without any explicit synchronization as
@@ -402,14 +402,14 @@ return term;</code>
<tag><marker id="dirty_nifs"/>Dirty NIF</tag>
<item>
<note>
- <p><em>The dirty NIF functionality described here
- is experimental</em>. Dirty NIF support is available only when
- the emulator is configured with dirty schedulers enabled. This
- feature is disabled by default. The Erlang runtime
- without SMP support does not support dirty schedulers even when
- the dirty scheduler support is enabled. To check at runtime for
- the presence of dirty scheduler threads, code can use the
- <seealso marker="#enif_system_info">
+ <p>Dirty NIF support is available only when the emulator is
+ configured with dirty scheduler support. As of ERTS version
+ 9.0, dirty scheduler support is enabled by default on the
+ runtime system with SMP support. The Erlang runtime without
+ SMP support does <em>not</em> support dirty schedulers even
+ when the dirty scheduler support is explicitly enabled. To
+ check at runtime for the presence of dirty scheduler threads,
+ code can use the <seealso marker="#enif_system_info">
<c>enif_system_info()</c></seealso> API function.</p>
</note>
<p>A NIF that cannot be split and cannot execute in a millisecond
@@ -525,7 +525,7 @@ return term;</code>
<p><c>load</c> is called when the NIF library is loaded
and no previously loaded library exists for this module.</p>
<p><c>*priv_data</c> can be set to point to some private data
- that the library needs to keep a state between NIF
+ if the library needs to keep a state between NIF
calls. <c>enif_priv_data</c> returns this pointer.
<c>*priv_data</c> is initialized to <c>NULL</c> when <c>load</c> is
called.</p>
@@ -642,9 +642,6 @@ typedef struct {
<p><c>flags</c> can be used to indicate that the NIF is a
<seealso marker="#dirty_nifs">dirty NIF</seealso> that is to be
executed on a dirty scheduler thread.</p>
- <p><em>The dirty NIF functionality described here is
- experimental.</em> You have to enable support for dirty
- schedulers when building OTP to try out the functionality.</p>
<p>If the dirty NIF is expected to be CPU-bound, its <c>flags</c>
field is to be set to <c>ERL_NIF_DIRTY_JOB_CPU_BOUND</c> or
<c>ERL_NIF_DIRTY_JOB_IO_BOUND</c>.</p>
@@ -2488,9 +2485,6 @@ enif_map_iterator_destroy(env, &amp;iter);</code>
application to break up long-running work into multiple regular NIF
calls or to schedule a <seealso marker="#dirty_nifs">
dirty NIF</seealso> to execute on a dirty scheduler thread.</p>
- <p><em>The dirty NIF functionality described here is
- experimental.</em> You have to enable support for dirty
- schedulers when building OTP to try out the functionality.</p>
<taglist>
<tag><c>fun_name</c></tag>
<item>
@@ -2501,7 +2495,7 @@ enif_map_iterator_destroy(env, &amp;iter);</code>
<tag><c>flags</c></tag>
<item>
<p>Must be set to <c>0</c> for a regular NIF. If the emulator was
- built with the experimental dirty scheduler support enabled,
+ built with dirty scheduler support enabled,
<c>flags</c> can be set to either
<c>ERL_NIF_DIRTY_JOB_CPU_BOUND</c> if the job is expected to be
CPU-bound, or <c>ERL_NIF_DIRTY_JOB_IO_BOUND</c> for
diff --git a/erts/doc/src/erlang.xml b/erts/doc/src/erlang.xml
index 3dad09365e..7815bfa510 100644
--- a/erts/doc/src/erlang.xml
+++ b/erts/doc/src/erlang.xml
@@ -4933,7 +4933,9 @@ RealSystem = system + MissedSystem</code>
<p>Returns the current call stack back-trace (<em>stacktrace</em>)
of the process. The stack has the same format as returned by
<seealso marker="#get_stacktrace/0">
- <c>erlang:get_stacktrace/0</c></seealso>.</p>
+ <c>erlang:get_stacktrace/0</c></seealso>. The depth of the
+ stacktrace is truncated according to the <c>backtrace_depth</c>
+ system flag setting.</p>
</item>
<tag><c>{dictionary, <anno>Dictionary</anno>}</c></tag>
<item>
@@ -6413,12 +6415,17 @@ lists:map(
<c><anno>TotalTime</anno></c> is the total time duration since
<seealso marker="#system_flag_scheduler_wall_time">
<c>scheduler_wall_time</c></seealso>
- activation. The time unit is undefined and can be subject
- to change between releases, OSs, and system restarts.
- <c>scheduler_wall_time</c> is only to be used to
- calculate relative values for scheduler-utilization.
- <c><anno>ActiveTime</anno></c> can never exceed
- <c><anno>TotalTime</anno></c>.</p>
+ activation for the specific scheduler. Note that
+ activation time can differ significantly between
+ schedulers. Currently dirty schedulers are activated
+ at system start while normal schedulers are activated
+ some time after the <c>scheduler_wall_time</c>
+ functionality is enabled. The time unit is undefined
+ and can be subject to change between releases, OSs,
+ and system restarts. <c>scheduler_wall_time</c> is only
+ to be used to calculate relative values for scheduler
+ utilization. <c><anno>ActiveTime</anno></c> can never
+ exceed <c><anno>TotalTime</anno></c>.</p>
<p>The definition of a busy scheduler is when it is not idle
and is not scheduling (selecting) a process or port,
that is:</p>
@@ -6436,15 +6443,37 @@ lists:map(
<c>scheduler_wall_time</c></seealso> is turned off.</p>
<p>The list of scheduler information is unsorted and can
appear in different order between calls.</p>
+ <p>As of ERTS version 9.0, also dirty CPU schedulers will
+ be included in the result. That is, all scheduler threads
+ that are expected to handle CPU bound work. If you also
+ want information about dirty I/O schedulers, use
+ <seealso marker="#statistics_scheduler_wall_time_all"><c>statistics(scheduler_wall_time_all)</c></seealso>
+ instead.</p>
+
+ <p>Normal schedulers will have scheduler identifiers in
+ the range <c>1 =&lt; <anno>SchedulerId</anno> =&lt;
+ </c><seealso marker="#system_info_schedulers"><c>erlang:system_info(schedulers)</c></seealso>.
+ Dirty CPU schedulers will have scheduler identifiers in
+ the range <c>erlang:system_info(schedulers) &lt;
+ <anno>SchedulerId</anno> =&lt; erlang:system_info(schedulers)
+ +
+ </c><seealso marker="#system_info_dirty_cpu_schedulers"><c>erlang:system_info(dirty_cpu_schedulers)</c></seealso>.
+ </p>
+ <note><p>The different types of schedulers handle
+ specific types of jobs. Every job is assigned to a specific
+ scheduler type. Jobs can migrate between different schedulers
+ of the same type, but never between schedulers of different
+ types. This fact has to be taken under consideration when
+ evaluating the result returned.</p></note>
<p>Using <c>scheduler_wall_time</c> to calculate
- scheduler-utilization:</p>
+ scheduler utilization:</p>
<pre>
> <input>erlang:system_flag(scheduler_wall_time, true).</input>
false
> <input>Ts0 = lists:sort(erlang:statistics(scheduler_wall_time)), ok.</input>
ok</pre>
<p>Some time later the user takes another snapshot and calculates
- scheduler-utilization per scheduler, for example:</p>
+ scheduler utilization per scheduler, for example:</p>
<pre>
> <input>Ts1 = lists:sort(erlang:statistics(scheduler_wall_time)), ok.</input>
ok
@@ -6459,11 +6488,32 @@ ok
{7,0.973237033077876},
{8,0.9741297293248656}]</pre>
<p>Using the same snapshots to calculate a total
- scheduler-utilization:</p>
+ scheduler utilization:</p>
<pre>
> <input>{A, T} = lists:foldl(fun({{_, A0, T0}, {_, A1, T1}}, {Ai,Ti}) ->
- {Ai + (A1 - A0), Ti + (T1 - T0)} end, {0, 0}, lists:zip(Ts0,Ts1)), A/T.</input>
+ {Ai + (A1 - A0), Ti + (T1 - T0)} end, {0, 0}, lists:zip(Ts0,Ts1)),
+ TotalSchedulerUtilization = A/T.</input>
+0.9769136803764825</pre>
+ <p>Total scheduler utilization will equal <c>1.0</c> when
+ all schedulers have been active all the time between the
+ two measurements.</p>
+ <p>Another (probably more) useful value is to calculate
+ total scheduler utilization weighted against maximum amount
+ of available CPU time:</p>
+ <pre>
+> <input>WeightedSchedulerUtilization = (TotalSchedulerUtilization
+ * (erlang:system_info(schedulers)
+ + erlang:system_info(dirty_cpu_schedulers)))
+ / erlang:system_info(logical_processors_available).</input>
0.9769136803764825</pre>
+ <p>This weighted scheduler utilization will reach <c>1.0</c>
+ when schedulers are active the same amount of time as
+ maximum available CPU time. If more schedulers exist
+ than available logical processors, this value may
+ be greater than <c>1.0</c>.</p>
+ <p>As of ERTS version 9.0, the Erlang runtime system
+ with SMP support will as default have more schedulers
+ than logical processors. This due to the dirty schedulers.</p>
<note>
<p><c>scheduler_wall_time</c> is by default disabled. To
enable it, use
@@ -6474,6 +6524,31 @@ ok
<func>
<name name="statistics" arity="1" clause_i="12"/>
+ <fsummary>Information about each schedulers work time.</fsummary>
+ <desc>
+ <marker id="statistics_scheduler_wall_time_all"></marker>
+ <p>The same as
+ <seealso marker="#statistics_scheduler_wall_time"><c>statistics(scheduler_wall_time)</c></seealso>,
+ except that it also include information about all dirty I/O
+ schedulers.</p>
+ <p>Dirty IO schedulers will have scheduler identifiers in
+ the range
+ <seealso marker="#system_info_schedulers"><c>erlang:system_info(schedulers)</c></seealso><c>
+ +
+ </c><seealso marker="#system_info_dirty_cpu_schedulers"><c>erlang:system_info(dirty_cpu_schedulers)</c></seealso><c> &lt;
+ <anno>SchedulerId</anno> =&lt; erlang:system_info(schedulers)
+ + erlang:system_info(dirty_cpu_schedulers)
+ +
+ </c><seealso marker="#system_info_dirty_io_schedulers"><c>erlang:system_info(dirty_io_schedulers)</c></seealso>.</p>
+ <note><p>Note that work executing on dirty I/O schedulers
+ are expected to mainly wait for I/O. That is, when you
+ get high scheduler utilization on dirty I/O schedulers,
+ CPU utilization is <em>not</em> expected to be high due to
+ this work.</p></note>
+ </desc>
+ </func>
+ <func>
+ <name name="statistics" arity="1" clause_i="13"/>
<fsummary>Information about active processes and ports.</fsummary>
<desc><marker id="statistics_total_active_tasks"></marker>
<p>Returns the total amount of active processes and ports in
@@ -6493,7 +6568,7 @@ ok
</func>
<func>
- <name name="statistics" arity="1" clause_i="13"/>
+ <name name="statistics" arity="1" clause_i="14"/>
<fsummary>Information about the run-queue lengths.</fsummary>
<desc><marker id="statistics_total_run_queue_lengths"></marker>
<p>Returns the total length of the run queues. That is, the number
@@ -6513,7 +6588,7 @@ ok
</func>
<func>
- <name name="statistics" arity="1" clause_i="14"/>
+ <name name="statistics" arity="1" clause_i="15"/>
<fsummary>Information about wall clock.</fsummary>
<desc>
<p>Returns information about wall clock. <c>wall_clock</c> can
@@ -6645,7 +6720,9 @@ ok
<fsummary>Set system flag <c>backtrace_depth</c>.</fsummary>
<desc>
<p>Sets the maximum depth of call stack back-traces in the
- exit reason element of <c>'EXIT'</c> tuples.</p>
+ exit reason element of <c>'EXIT'</c> tuples. The flag
+ also limits the stacktrace depth returned by <c>process_info</c>
+ item <c>current_stacktrace.</c></p>
<p>Returns the old value of the flag.</p>
</desc>
</func>
@@ -6717,11 +6794,6 @@ ok
down to 3. Similarly, the number of dirty CPU schedulers
online increases proportionally to increases in the number of
schedulers online.</p>
- <note>
- <p>The dirty schedulers functionality is experimental.
- Enable support for dirty schedulers when building OTP to
- try out the functionality.</p>
- </note>
<p>For more information, see
<seealso marker="#system_info_dirty_cpu_schedulers">
<c>erlang:system_info(dirty_cpu_schedulers)</c></seealso> and
@@ -7224,8 +7296,8 @@ ok
</func>
<func>
- <name name="system_info" arity="1" clause_i="11"/>
<name name="system_info" arity="1" clause_i="12"/>
+ <name name="system_info" arity="1" clause_i="13"/>
<fsummary>Information about the CPU topology of the system.</fsummary>
<type name="cpu_topology"/>
<type name="level_entry"/>
@@ -7325,12 +7397,12 @@ ok
</func>
<func>
- <name name="system_info" arity="1" clause_i="28"/>
<name name="system_info" arity="1" clause_i="29"/>
- <name name="system_info" arity="1" clause_i="37"/>
+ <name name="system_info" arity="1" clause_i="30"/>
<name name="system_info" arity="1" clause_i="38"/>
<name name="system_info" arity="1" clause_i="39"/>
<name name="system_info" arity="1" clause_i="40"/>
+ <name name="system_info" arity="1" clause_i="41"/>
<fsummary>Information about the default process heap settings.</fsummary>
<type name="message_queue_data"/>
<type name="max_heap_size"/>
@@ -7408,7 +7480,7 @@ ok
<name name="system_info" arity="1" clause_i="8"/>
<name name="system_info" arity="1" clause_i="9"/>
<name name="system_info" arity="1" clause_i="10"/>
- <name name="system_info" arity="1" clause_i="13"/>
+ <name name="system_info" arity="1" clause_i="11"/>
<name name="system_info" arity="1" clause_i="14"/>
<name name="system_info" arity="1" clause_i="15"/>
<name name="system_info" arity="1" clause_i="16"/>
@@ -7423,14 +7495,14 @@ ok
<name name="system_info" arity="1" clause_i="25"/>
<name name="system_info" arity="1" clause_i="26"/>
<name name="system_info" arity="1" clause_i="27"/>
- <name name="system_info" arity="1" clause_i="30"/>
+ <name name="system_info" arity="1" clause_i="28"/>
<name name="system_info" arity="1" clause_i="31"/>
<name name="system_info" arity="1" clause_i="32"/>
<name name="system_info" arity="1" clause_i="33"/>
<name name="system_info" arity="1" clause_i="34"/>
<name name="system_info" arity="1" clause_i="35"/>
<name name="system_info" arity="1" clause_i="36"/>
- <name name="system_info" arity="1" clause_i="41"/>
+ <name name="system_info" arity="1" clause_i="37"/>
<name name="system_info" arity="1" clause_i="42"/>
<name name="system_info" arity="1" clause_i="43"/>
<name name="system_info" arity="1" clause_i="44"/>
@@ -7460,11 +7532,18 @@ ok
<name name="system_info" arity="1" clause_i="68"/>
<name name="system_info" arity="1" clause_i="69"/>
<name name="system_info" arity="1" clause_i="70"/>
+ <name name="system_info" arity="1" clause_i="71"/>
<fsummary>Information about the system.</fsummary>
<desc>
<p>Returns various information about the current system
(emulator) as specified by <c><anno>Item</anno></c>:</p>
<taglist>
+ <tag><c>atom_count</c></tag>
+ <item>
+ <marker id="system_info_atom_count"></marker>
+ <p>Returns the number of atoms currently existing at the
+ local node. The value is given as an integer.</p>
+ </item>
<tag><c>atom_limit</c></tag>
<item>
<marker id="system_info_atom_limit"></marker>
@@ -7559,9 +7638,6 @@ ok
<seealso marker="erts:erl#+SDcpu"><c>+SDcpu</c></seealso> or
<seealso marker="erts:erl#+SDPcpu"><c>+SDPcpu</c></seealso> in
<c>erl(1)</c>.</p>
- <p>Notice that the dirty schedulers functionality is
- experimental. Enable support for dirty schedulers when
- building OTP to try out the functionality.</p>
<p>See also
<seealso marker="#system_flag_dirty_cpu_schedulers_online">
<c>erlang:system_flag(dirty_cpu_schedulers_online,
@@ -7591,9 +7667,6 @@ ok
startup by passing command-line flag
<seealso marker="erts:erl#+SDcpu"><c>+SDcpu</c></seealso> in
<c>erl(1)</c>.</p>
- <p>Notice that the dirty schedulers functionality is
- experimental. Enable support for dirty schedulers when
- building OTP to try out the functionality.</p>
<p>For more information, see
<seealso marker="#system_info_dirty_cpu_schedulers">
<c>erlang:system_info(dirty_cpu_schedulers)</c></seealso>,
@@ -7615,9 +7688,6 @@ ok
<p>This value can be set at startup by passing command-line
argument <seealso marker="erts:erl#+SDio"><c>+SDio</c></seealso>
in <c>erl(1)</c>.</p>
- <p>Notice that the dirty schedulers functionality is
- experimental. Enable support for dirty schedulers when
- building OTP to try out the functionality.</p>
<p>For more information, see
<seealso marker="#system_info_dirty_cpu_schedulers">
<c>erlang:system_info(dirty_cpu_schedulers)</c></seealso>,
diff --git a/erts/doc/src/notes.xml b/erts/doc/src/notes.xml
index dd260f2d1f..812538729d 100644
--- a/erts/doc/src/notes.xml
+++ b/erts/doc/src/notes.xml
@@ -32,6 +32,179 @@
<p>This document describes the changes made to the ERTS application.</p>
+<section><title>Erts 8.2.1</title>
+
+ <section><title>Fixed Bugs and Malfunctions</title>
+ <list>
+ <item>
+ <p>
+ Fix a quite rare bug causing VM crash during code loading
+ and the use of export funs (fun M:F/A) of not yet loaded
+ modules. Requires a very specfic timing of concurrent
+ scheduler threads. Has been seen on ARM but can probably
+ also occure on other architectures. Bug has existed since
+ OTP R16.</p>
+ <p>
+ Own Id: OTP-14144 Aux Id: seq13242 </p>
+ </item>
+ </list>
+ </section>
+
+</section>
+
+<section><title>Erts 8.2</title>
+
+ <section><title>Fixed Bugs and Malfunctions</title>
+ <list>
+ <item>
+ <p>
+ Fixed <c>configure</c> failures on MacOSX. Most important
+ <c>clock_gettime()</c> was detected when building for
+ MacOSX - El Capitan using XCode 8 despite it is not
+ available until MacOSX - Sierra.</p>
+ <p>
+ Own Id: OTP-13904 Aux Id: ERL-256 </p>
+ </item>
+ <item>
+ <p>
+ <c>code:add_pathsa/1</c> and command line option
+ <c>-pa</c> both revert the given list of directories when
+ adding it at the beginning of the code path. This is now
+ documented.</p>
+ <p>
+ Own Id: OTP-13920 Aux Id: ERL-267 </p>
+ </item>
+ <item>
+ <p>
+ Fix a compilation error of erts in OpenBSD related to the
+ usage of the __errno variable.</p>
+ <p>
+ Own Id: OTP-13927</p>
+ </item>
+ <item>
+ <p>
+ Fixed so that when enabling tracing on a process that had
+ an invalid tracer associated with it, the new tracer
+ overwrites the old tracer. Before this fix, calling
+ erlang:trace/3 would behave as if the tracer was still
+ alive and not apply the new trace.</p>
+ <p>
+ This fault was introduced in ERTS 8.0.</p>
+ <p>
+ Own Id: OTP-13928</p>
+ </item>
+ <item>
+ <p>
+ Fix parsing of <c>-profile_boot 'true' | 'false'</c></p>
+ <p>
+ Own Id: OTP-13955 Aux Id: ERL-280 </p>
+ </item>
+ <item>
+ <p>
+ A slight improvement of <c>erlang:get_stacktrace/0</c>
+ for exceptions raised in hipe compiled code. Beam
+ compiled functions in such stack trace was earlier
+ replaced by some unrelated function. They are now instead
+ omitted. This is an attempt to reduce the confusion in
+ the absence of a complete and correct stack trace for
+ mixed beam and hipe functions.</p>
+ <p>
+ Own Id: OTP-13992</p>
+ </item>
+ <item>
+ <p> Correct type declaration of match specification head.
+ </p>
+ <p>
+ Own Id: OTP-13996</p>
+ </item>
+ <item>
+ <p>
+ HiPE code loading failed for x86_64 if gcc was configured
+ with <c>--enable-default-pie</c>. Fixed by disabling PIE,
+ if needed for HiPE, when building the VM.</p>
+ <p>
+ Own Id: OTP-14031 Aux Id: ERL-294, PR-1239 </p>
+ </item>
+ <item>
+ <p>
+ Faulty arguments could be presented on exception from a
+ NIF that had rescheduled itself using
+ <c>enif_schedule_nif()</c>.</p>
+ <p>
+ Own Id: OTP-14048</p>
+ </item>
+ <item>
+ <p>
+ The runtime system could crash if a garbage collection on
+ a process was performed immediately after a NIF had been
+ rescheduled using <c>enif_schedule_nif()</c>.</p>
+ <p>
+ Own Id: OTP-14049</p>
+ </item>
+ <item>
+ <p>
+ A reference to purged code could be left undetected by
+ the purge operation if a process just had rescheduled a
+ NIF call using <c>enif_schedule_nif()</c> when the
+ process was checked. This could cause a runtime system
+ crash.</p>
+ <p>
+ Own Id: OTP-14050</p>
+ </item>
+ <item>
+ <p>Fixed a number of dirty scheduler related bugs:</p>
+ <list> <item><p>Process priority was not handled correct
+ when scheduling on a dirty scheduler.</p></item>
+ <item><p>The runtime system could crash when an exit
+ signal with a compound exit reason was sent to a process
+ executing on a dirty scheduler.</p></item> <item><p>The
+ runtime system crashed when call tracing a process
+ executing on a dirty scheduler.</p></item> <item><p>A
+ code purge operation could end up hanging forever when a
+ process executed on a dirty scheduler</p></item> </list>
+ <p>
+ Own Id: OTP-14051</p>
+ </item>
+ </list>
+ </section>
+
+
+ <section><title>Improvements and New Features</title>
+ <list>
+ <item>
+ <p>
+ Fix minor soft purge race bug that could incorrectly
+ trigger code_server to load new code for the module if
+ the soft purge failed and no current version of the
+ module existed.</p>
+ <p>
+ Own Id: OTP-13925</p>
+ </item>
+ <item>
+ <p>
+ To ease troubleshooting, <c>erlang:load_nif/2</c> now
+ includes the return value from a failed call to
+ load/reload/upgrade in the text part of the error tuple.
+ The <c>crypto</c> NIF makes use of this feature by
+ returning the source line where/if the initialization
+ fails.</p>
+ <p>
+ Own Id: OTP-13951</p>
+ </item>
+ <item>
+ <p>
+ New environment variable <c>ERL_CRASH_DUMP_BYTES</c> can
+ be used to limit the size of crash dumps. If the limit is
+ reached, crash dump generation is aborted and the
+ generated file will be truncated.</p>
+ <p>
+ Own Id: OTP-14046</p>
+ </item>
+ </list>
+ </section>
+
+</section>
+
<section><title>Erts 8.1.1</title>
<section><title>Fixed Bugs and Malfunctions</title>