File 2221-Improved-memsup-get_system_memory_data.patch of Package erlang
From 8742e05927072aade44ae85d378e561887334362 Mon Sep 17 00:00:00 2001
From: Rickard Green <rickard@erlang.org>
Date: Thu, 15 Oct 2020 08:05:24 +0200
Subject: [PATCH] Improved memsup:get_system_memory_data()
Change the behaviour of memsup:get_system_memory_data() to the
behaviour that previously was enabled by setting the application
parameter 'memsup_improved_system_memory_data' to 'true'.
---
lib/os_mon/doc/src/memsup.xml | 90 +++++++-------------------------
lib/os_mon/src/memsup.erl | 72 ++++++++++---------------
lib/os_mon/test/memsup_SUITE.erl | 11 ++--
3 files changed, 51 insertions(+), 122 deletions(-)
diff --git a/lib/os_mon/doc/src/memsup.xml b/lib/os_mon/doc/src/memsup.xml
index a6f93fdba6..2e61fb9254 100644
--- a/lib/os_mon/doc/src/memsup.xml
+++ b/lib/os_mon/doc/src/memsup.xml
@@ -121,25 +121,6 @@
systems with many concurrent processes, as each process memory
check makes a traversal of the entire list of processes.</p>
</item>
- <tag><marker id="memsup_improved_system_memory_data"/><c>memsup_improved_system_memory_data = bool()</c></tag>
- <item>
- <p>Determines the behaviour of the
- <seemfa marker="#get_system_memory_data/0"><c>get_system_memory_data()</c></seemfa>
- function. When this configuration parameter is <c>false</c>,
- <c>get_system_memory_data()</c> behaves as it has done
- up until the point of the introduction of the configuration
- parameter. When set to <c>true</c> new tagged tuples are
- allowed in the result. Such new tuples may be introduced at
- any time without prior notice. The classification of
- <c>cached_memory</c> on Linux systems will also change so that
- more memory is classified as <c>cached_memory</c>.
- </p>
- <note><p>This configuration parameter defaults <c>false</c> and will
- do so up until OTP 23. As of OTP 24 this configuration parameter
- will be removed and <c>get_system_memory_data()</c> will begin
- behaving as it does now when the configuration parameter has
- been set to <c>true</c>.</p></note>
- </item>
</taglist>
<p>See <seefile marker="kernel:config">config(4)</seefile> for
information about how to change the value of configuration
@@ -185,12 +166,24 @@
<desc>
<p>Invokes a memory check and returns the resulting, system
dependent, data as a list of tagged tuples, where <c>Tag</c>
- can be one of the following:</p>
+ currently can be one of the following:</p>
<taglist>
<tag><c>total_memory</c></tag>
<item>The total amount of memory available to the Erlang emulator,
allocated and free. May or may not be equal to the amount
- of memory configured in the system.</item>
+ of memory configured in the system.</item>
+ <tag><c>available_memory</c></tag>
+ <item>Informs about the amount memory that is available for
+ increased usage if there is an increased memory need. This
+ value is not based on a calculation of the other provided
+ values and should give a better value of the amount of memory
+ that actually is available than calculating a value based on
+ the other values reported. This value is currently only present
+ on newer Linux kernels. If this value is not available on Linux,
+ you can use the sum of <c>cached_memory</c>,
+ <c>buffered_memory</c>, and <c>free_memory</c> as an
+ approximation.
+ </item>
<tag><c>free_memory</c></tag>
<item>The amount of free memory available to the Erlang emulator
for allocation.</item>
@@ -205,6 +198,8 @@
<tag><c>cached_memory</c></tag>
<item>
The amount of memory the system uses for cached files read from disk.
+ On Linux, also memory marked as reclaimable in the kernel slab
+ allocator will be added to this value.
</item>
<tag><c>total_swap</c></tag>
<item>
@@ -218,62 +213,15 @@
</taglist>
+ <note><p>Note that new tagged tuples may be introduced in the result
+ at any time without prior notice</p></note>
+
<p>Note that the order of the tuples in the resulting list is undefined
and may change at any time.</p>
<p>All memory sizes are presented as number of <em>bytes</em>.</p>
<p>Returns the empty list [] if <c>memsup</c> is not available,
or if the memory check times out.</p>
- <note><p>
- On Linux the memory available to the emulator is <c>cached_memory</c> and
- <c>buffered_memory</c> in addition to <c>free_memory</c>.</p>
- </note>
-
- <p>The above describes how it works if the configuration parameter
- <seeerl marker="#memsup_improved_system_memory_data"><c>memsup_improved_system_memory_data</c></seeerl>
- has been set to <c>false</c> which currently also is the default
- behavior. If the configuration parameter is set to <c>true</c> the
- behavior is slightly changed:</p>
- <list>
- <item>
- <p>
- New tagged tuples may be added in the resulting
- list at any time.
- </p>
- </item>
- <item>
- <p>
- On Linux systems the following changes will be made:
- </p>
- <list>
- <item>
- <p>
- A new tuple with the tag <c>available_memory</c> will be
- added to the result when this value is provided by the
- kernel. The <c>available_memory</c> value informs about
- the amount memory that is available for use if there is
- an increased memory need. This value is not based on a
- calculation of the other provided values and should give
- a better value of the amount of memory that actually is
- available than calculating a value based on the other
- values reported.
- </p>
- </item>
- <item>
- <p>The classification of <c>cached_memory</c> is changed.
- Also memory marked as reclaimable in the kernel slab
- allocator will be added to the value presented as
- <c>cached_memory</c>.
- </p>
- </item>
- </list>
- </item>
- </list>
- <note><p>As of OTP 24 <c>memsup_improved_system_memory_data</c>
- configuration parameter will be removed and
- <c>get_system_memory_data()</c> will begin behaving as it does
- now when the configuration parameter has been set to
- <c>true</c>.</p></note>
</desc>
</func>
<func>
diff --git a/lib/os_mon/src/memsup.erl b/lib/os_mon/src/memsup.erl
index fdd08eed63..e529334226 100644
--- a/lib/os_mon/src/memsup.erl
+++ b/lib/os_mon/src/memsup.erl
@@ -57,7 +57,6 @@
ext_wd_timer, % undefined | TimerRef
pending = [], % [reg | {reg,From} | {ext,From}]
ext_pending = [] % [{ext,From}]
-%%% ismd = false % Improved system memory data enabled?
}).
-define(EXT_MEM_MAP, memsup_ext_memory_type_map__).
@@ -149,7 +148,6 @@ dummy_reply(get_memory_data, true) ->
dummy_reply(get_memory_data, false) ->
{0,0,{self(),0}}.
-param_type(memsup_improved_system_memory_data, Val) when Val==true; Val==false -> true;
param_type(memsup_system_only, Val) when Val==true; Val==false -> true;
param_type(memory_check_interval, Val) when is_integer(Val),
Val>0 -> true;
@@ -163,7 +161,6 @@ param_type(process_memory_high_watermark, Val) when is_number(Val),
Val=<1 -> true;
param_type(_Param, _Val) -> false.
-param_default(memsup_improved_system_memory_data) -> false;
param_default(memsup_system_only) -> false;
param_default(memory_check_interval) -> 1;
param_default(memsup_helper_timeout) -> 30;
@@ -195,11 +192,9 @@ init([]) ->
exit({unsupported_os, OS})
end,
- ISMD = os_mon:get_env(memsup, memsup_improved_system_memory_data),
-
Pid = if
PortMode ->
- spawn_link(fun() -> port_init(ISMD) end);
+ spawn_link(fun() -> port_init() end);
not PortMode ->
undefined
end,
@@ -236,7 +231,6 @@ init([]) ->
helper_timeout = sec_to_ms(HelperTimeout),
sys_mem_watermark = SysMem,
proc_mem_watermark = ProcMem,
-%%% ismd = ISMD,
pid=Pid}}.
@@ -648,10 +642,10 @@ get_ext_memory_usage(OS, {Alloc, Total}) ->
%%--Collect memory data, using port-------------------------------------
-port_init(ISMD) ->
+port_init() ->
process_flag(trap_exit, true),
Port = start_portprogram(),
- port_idle(Port, ISMD).
+ port_idle(Port).
start_portprogram() ->
os_mon:open_port("memsup",[{packet,1}]).
@@ -664,20 +658,20 @@ start_portprogram() ->
%% should still wait for port response (which should come
%% eventually!) but not receive any requests or cancellations
%% meanwhile to prevent getting out of synch.
-port_idle(Port, ISMD) ->
+port_idle(Port) ->
receive
{Memsup, collect_sys} ->
Port ! {self(), {command, [?SHOW_MEM]}},
- get_memory_usage(Port, undefined, Memsup, ISMD);
+ get_memory_usage(Port, undefined, Memsup);
{Memsup, collect_ext_sys} ->
Port ! {self(), {command, [?SHOW_SYSTEM_MEM]}},
- get_ext_memory_usage(Port, #{}, Memsup, ISMD);
+ get_ext_memory_usage(Port, #{}, Memsup);
cancel ->
%% Received after reply already has been delivered...
- port_idle(Port, ISMD);
+ port_idle(Port);
ext_cancel ->
%% Received after reply already has been delivered...
- port_idle(Port, ISMD);
+ port_idle(Port);
close ->
port_close(Port);
{Port, {data, Data}} ->
@@ -688,16 +682,16 @@ port_idle(Port, ISMD) ->
port_close(Port)
end.
-get_memory_usage(Port, Alloc, Memsup, ISMD) ->
+get_memory_usage(Port, Alloc, Memsup) ->
receive
{Port, {data, Data}} when Alloc==undefined ->
- get_memory_usage(Port, erlang:list_to_integer(Data, 16), Memsup, ISMD);
+ get_memory_usage(Port, erlang:list_to_integer(Data, 16), Memsup);
{Port, {data, Data}} ->
Total = erlang:list_to_integer(Data, 16),
Memsup ! {collected_sys, {Alloc, Total}},
- port_idle(Port, ISMD);
+ port_idle(Port);
cancel ->
- get_memory_usage_cancelled(Port, Alloc, ISMD);
+ get_memory_usage_cancelled(Port, Alloc);
close ->
port_close(Port);
{'EXIT', Port, Reason} ->
@@ -705,12 +699,12 @@ get_memory_usage(Port, Alloc, Memsup, ISMD) ->
{'EXIT', _Memsup, _Reason} ->
port_close(Port)
end.
-get_memory_usage_cancelled(Port, Alloc, ISMD) ->
+get_memory_usage_cancelled(Port, Alloc) ->
receive
{Port, {data, _Data}} when Alloc==undefined ->
- get_memory_usage_cancelled(Port, 0, ISMD);
+ get_memory_usage_cancelled(Port, 0);
{Port, {data, _Data}} ->
- port_idle(Port, ISMD);
+ port_idle(Port);
close ->
port_close(Port);
{'EXIT', Port, Reason} ->
@@ -728,24 +722,16 @@ tag2atag(Port, Tag) ->
exit({memsup_port_error, {Port,[Tag]}})
end.
-get_ext_memory_usage(Port, Accum, Memsup, ISMD) ->
+get_ext_memory_usage(Port, Accum, Memsup) ->
receive
{Port, {data, [?SHOW_SYSTEM_MEM_END]}} ->
Memsup ! {collected_ext_sys, maps:to_list(Accum)},
- port_idle(Port, ISMD);
- {Port, {data, [?MEM_CACHED_X]}} when ISMD == false ->
- %% Improved system memory data not enabled; drop value...
- get_ext_memory_usage(tag2atag(Port, ?MEM_CACHED_X), Port,
- Accum, Memsup, ISMD, true);
- {Port, {data, [?MEM_AVAIL]}} when ISMD == false ->
- %% Improved system memory data not enabled; drop value...
- get_ext_memory_usage(tag2atag(Port, ?MEM_AVAIL), Port,
- Accum, Memsup, ISMD, true);
+ port_idle(Port);
{Port, {data, [Tag]}} ->
get_ext_memory_usage(tag2atag(Port, Tag), Port, Accum,
- Memsup, ISMD, false);
+ Memsup);
ext_cancel ->
- get_ext_memory_usage_cancelled(Port, ISMD);
+ get_ext_memory_usage_cancelled(Port);
close ->
port_close(Port);
{'EXIT', Port, Reason} ->
@@ -753,13 +739,13 @@ get_ext_memory_usage(Port, Accum, Memsup, ISMD) ->
{'EXIT', _Memsup, _Reason} ->
port_close(Port)
end.
-get_ext_memory_usage_cancelled(Port, ISMD) ->
+get_ext_memory_usage_cancelled(Port) ->
receive
{Port, {data, [?SHOW_SYSTEM_MEM_END]}} ->
- port_idle(Port, ISMD);
+ port_idle(Port);
{Port, {data, [Tag]}} ->
get_ext_memory_usage_cancelled(tag2atag(Port, Tag),
- Port, ISMD);
+ Port);
close ->
port_close(Port);
{'EXIT', Port, Reason} ->
@@ -768,11 +754,9 @@ get_ext_memory_usage_cancelled(Port, ISMD) ->
port_close(Port)
end.
-get_ext_memory_usage(ATag, Port, Accum0, Memsup, ISMD, Drop) ->
+get_ext_memory_usage(ATag, Port, Accum0, Memsup) ->
receive
- {Port, {data, _Data}} when Drop == true ->
- get_ext_memory_usage(Port, Accum0, Memsup, ISMD);
- {Port, {data, Data}} when Drop == false ->
+ {Port, {data, Data}} ->
Value = erlang:list_to_integer(Data, 16),
Accum = case maps:get(ATag, Accum0, undefined) of
undefined ->
@@ -780,9 +764,9 @@ get_ext_memory_usage(ATag, Port, Accum0, Memsup, ISMD, Drop) ->
PrevValue ->
maps:put(ATag, Value + PrevValue, Accum0)
end,
- get_ext_memory_usage(Port, Accum, Memsup, ISMD);
+ get_ext_memory_usage(Port, Accum, Memsup);
cancel ->
- get_ext_memory_usage_cancelled(ATag, Port, ISMD);
+ get_ext_memory_usage_cancelled(ATag, Port);
close ->
port_close(Port);
{'EXIT', Port, Reason} ->
@@ -790,10 +774,10 @@ get_ext_memory_usage(ATag, Port, Accum0, Memsup, ISMD, Drop) ->
{'EXIT', _Memsup, _Reason} ->
port_close(Port)
end.
-get_ext_memory_usage_cancelled(_ATag, Port, ISMD) ->
+get_ext_memory_usage_cancelled(_ATag, Port) ->
receive
{Port, {data, _Data}} ->
- get_ext_memory_usage_cancelled(Port, ISMD);
+ get_ext_memory_usage_cancelled(Port);
close ->
port_close(Port);
{'EXIT', Port, Reason} ->
diff --git a/lib/os_mon/test/memsup_SUITE.erl b/lib/os_mon/test/memsup_SUITE.erl
index 97f97e21cc..1892c49583 100644
--- a/lib/os_mon/test/memsup_SUITE.erl
+++ b/lib/os_mon/test/memsup_SUITE.erl
@@ -32,7 +32,8 @@
-define(SYSTEM_MEMORY_DATA_TAGS,
- [total_memory,
+ [available_memory,
+ total_memory,
free_memory,
system_total_memory,
largest_free,
@@ -43,10 +44,6 @@
buffered_memory,
shared_memory]).
--define(IMPROVED_SYSTEM_MEMORY_DATA_TAGS,
- [available_memory | ?SYSTEM_MEMORY_DATA_TAGS]).
-
-
init_per_suite(Config) when is_list(Config) ->
ok = application:start(os_mon),
Config.
@@ -726,7 +723,7 @@ otp_5910(Config) when is_list(Config) ->
ok.
improved_system_memory_data(Config) ->
- {ok, Node} = start_node(Config, "-os_mon memsup_improved_system_memory_data true"),
+ {ok, Node} = start_node(Config),
ok = rpc:call(Node, application, start, [sasl]),
ok = rpc:call(Node, application, start, [os_mon]),
@@ -734,7 +731,7 @@ improved_system_memory_data(Config) ->
stop_node(Node),
- Tags = ?IMPROVED_SYSTEM_MEMORY_DATA_TAGS,
+ Tags = ?SYSTEM_MEMORY_DATA_TAGS,
AvailableMemoryPresent
= lists:foldl(fun ({Tag,Value}, AMP) when is_atom(Tag),
is_integer(Value),
--
2.26.2
