meson: add -Dmemory-accounting-default=true|false

This makes it easy to set the default for distributions and users which want to
default to off because they primarily use older kernels.

NEWS

@@ -6,15 +6,15 @@ CHANGES WITH 238 in spe:
           discussions with the upstream control group maintainers we learnt
           that the negative impact of cgroup memory accounting on current
           kernels is finally relatively minimal, so that it should be safe to
-          enable this by default without affecting system performance too
+          enable this by default without affecting system performance. Besides
-          much. Besides memory accounting only tasks accounting is turned on by
+          memory accounting only task accounting is turned on by default, all
-          default, all other forms of resource accounting (CPU, IO, IP) remain
+          other forms of resource accounting (CPU, IO, IP) remain off for now,
-          off for now, because it's not clear yet that their impact is small
+          because it's not clear yet that their impact is small enough to move
-          enough to move from opt-in to opt-out for them, too. We recommend
+          from opt-in to opt-out. We recommend downstreams to leave memory
-          downstreams to leave memory accounting on by default, however in some
+          accounting on by default if kernel 4.14 or higher is are primarily
-          situations it might be wise to revert this change of defaults, in
+          used. On very resource constrained systems or when support for old
-          particular on very resource constrained systems or when support for
+          kernels is a necessity, -Dmemory-accounting-default=false can be used
-          old kernels is a necessity.
+          to revert this change.
 
 CHANGES WITH 237:
 

man/custom-entities.ent.in

@@ -6,3 +6,4 @@
 <!ENTITY systemenvgeneratordir @SYSTEM_ENV_GENERATOR_PATH@>
 <!ENTITY userenvgeneratordir @USER_ENV_GENERATOR_PATH@>
 <!ENTITY CERTIFICATE_ROOT @CERTIFICATE_ROOT@>
+<!ENTITY MEMORY_ACCOUNTING_DEFAULT @MEMORY_ACCOUNTING_DEFAULT_ON_OFF@>

man/systemd-system.conf.xml

@@ -1,6 +1,9 @@
 <?xml version='1.0'?> <!--*- Mode: nxml; nxml-child-indent: 2; indent-tabs-mode: nil -*-->
 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
-  "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
+  "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd" [
+<!ENTITY % entities SYSTEM "custom-entities.ent" >
+%entities;
+]>
 
 <!--
   SPDX-License-Identifier: LGPL-2.1+
@@ -338,8 +341,9 @@
         <varname>CPUAccounting=</varname>, <varname>BlockIOAccounting=</varname>, <varname>MemoryAccounting=</varname>,
         <varname>TasksAccounting=</varname> and <varname>IPAccounting=</varname>. See
         <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>
-        for details on the per-unit settings. <varname>DefaultTasksAccounting=</varname> and
+        for details on the per-unit settings. <varname>DefaultTasksAccounting=</varname> defaults to on,
-        <varname>DefaultMemoryAccounting=</varname> default to on, the other three settings to off.</para></listitem>
+        <varname>DefaultMemoryAccounting=</varname> to &MEMORY_ACCOUNTING_DEFAULT;,
+        the other three settings to off.</para></listitem>
       </varlistentry>
 
       <varlistentry>

meson.build

@@ -172,6 +172,8 @@ if pamconfdir == ''
         pamconfdir = join_paths(sysconfdir, 'pam.d')
 endif
 
+memory_accounting_default = get_option('memory-accounting-default')
+
 conf.set_quoted('PKGSYSCONFDIR',                              pkgsysconfdir)
 conf.set_quoted('SYSTEM_CONFIG_UNIT_PATH',                    join_paths(pkgsysconfdir, 'system'))
 conf.set_quoted('SYSTEM_DATA_UNIT_PATH',                      systemunitdir)
@@ -217,6 +219,8 @@ conf.set_quoted('SYSTEMD_EXPORT_PATH',                        join_paths(rootlib
 conf.set_quoted('VENDOR_KEYRING_PATH',                        join_paths(rootlibexecdir, 'import-pubring.gpg'))
 conf.set_quoted('USER_KEYRING_PATH',                          join_paths(pkgsysconfdir, 'import-pubring.gpg'))
 conf.set_quoted('DOCUMENT_ROOT',                              join_paths(pkgdatadir, 'gatewayd'))
+conf.set('MEMORY_ACCOUNTING_DEFAULT',                         memory_accounting_default ? 'true' : 'false')
+conf.set_quoted('MEMORY_ACCOUNTING_DEFAULT_ON_OFF',           memory_accounting_default ? 'on' : 'off')
 
 conf.set_quoted('ABS_BUILD_DIR',                              meson.build_root())
 conf.set_quoted('ABS_SRC_DIR',                                meson.source_root())
@@ -257,6 +261,7 @@ substs.set('SYSTEM_SYSVINIT_PATH',                            sysvinit_path)
 substs.set('SYSTEM_SYSVRCND_PATH',                            sysvrcnd_path)
 substs.set('RC_LOCAL_SCRIPT_PATH_START',                      get_option('rc-local'))
 substs.set('RC_LOCAL_SCRIPT_PATH_STOP',                       get_option('halt-local'))
+substs.set('MEMORY_ACCOUNTING_DEFAULT',                       memory_accounting_default ? 'yes' : 'no')
 
 #####################################################################
 

meson_options.txt

@@ -53,6 +53,8 @@ option('debug-tty', type : 'string', value : '/dev/tty9',
        description : 'specify the tty device for debug shell')
 option('debug', type : 'string',
        description : 'enable extra debugging (hashmap,mmap-cache)')
+option('memory-accounting-default', type : 'boolean',
+       description : 'enable MemoryAccounting= by default')
 
 option('utmp', type : 'boolean',
        description : 'support for utmp/wtmp log handling')

src/core/main.c

@@ -135,7 +135,7 @@ static bool arg_default_cpu_accounting = false;
 static bool arg_default_io_accounting = false;
 static bool arg_default_ip_accounting = false;
 static bool arg_default_blockio_accounting = false;
-static bool arg_default_memory_accounting = true;
+static bool arg_default_memory_accounting = MEMORY_ACCOUNTING_DEFAULT;
 static bool arg_default_tasks_accounting = true;
 static uint64_t arg_default_tasks_max = UINT64_MAX;
 static sd_id128_t arg_machine_id = {};

src/core/manager.c

@@ -673,7 +673,7 @@ int manager_new(UnitFileScope scope, unsigned test_run_flags, Manager **_m) {
         m->unit_file_scope = scope;
         m->exit_code = _MANAGER_EXIT_CODE_INVALID;
         m->default_timer_accuracy_usec = USEC_PER_MINUTE;
-        m->default_memory_accounting = true;
+        m->default_memory_accounting = MEMORY_ACCOUNTING_DEFAULT;
         m->default_tasks_accounting = true;
         m->default_tasks_max = UINT64_MAX;
         m->default_timeout_start_usec = DEFAULT_TIMEOUT_USEC;

src/core/meson.build

@@ -186,7 +186,8 @@ systemd_shutdown_sources = files('''
 
 in_files = [['macros.systemd',   rpmmacrosdir],
             ['triggers.systemd', ''],
-            ['systemd.pc',       pkgconfigdatadir]]
+            ['systemd.pc',       pkgconfigdatadir],
+            ['system.conf',      pkgsysconfdir]]
 
 foreach item : in_files
         file = item[0]
@@ -225,8 +226,7 @@ i18n.merge_file(
         install : install_polkit,
         install_dir : polkitpolicydir)
 
-install_data('system.conf',
+install_data('user.conf',
-             'user.conf',
              install_dir : pkgsysconfdir)
 
 meson.add_install_script('sh', '-c', mkdir_p.format(systemshutdowndir))

src/core/system.conf.in

@@ -42,7 +42,7 @@
 #DefaultIOAccounting=no
 #DefaultIPAccounting=no
 #DefaultBlockIOAccounting=no
-#DefaultMemoryAccounting=yes
+#DefaultMemoryAccounting=@MEMORY_ACCOUNTING_DEFAULT@
 #DefaultTasksAccounting=yes
 #DefaultTasksMax=15%
 #DefaultLimitCPU=