[systemd-devel] [PATCH 1/1] RFC: Set the Default OOM Score from configuration file

[Sangjung Woo]

If 'OOMScoreAdjust' option is ommited from unit file, this patch makes
the executed process's oom_score_adj as default OOM score in case of
explicitly 'DefaultOOMScore' is declared in configuration file.
(i.e. system.conf and user.conf)

If the unit file has 'OOMScoreAdjust' option, set the its oom_score_adj
as declared value as before.

Signed-off-by: Sangjung Woo <again4you at gmail.com>
---
 src/core/main.c      |    8 ++++++++
 src/core/system.conf |    1 +
 src/core/user.conf   |    1 +
 3 files changed, 10 insertions(+)

diff --git a/src/core/main.c b/src/core/main.c
index 22cec4e..e8bb015 100644
--- a/src/core/main.c
+++ b/src/core/main.c
@@ -90,6 +90,7 @@ static bool arg_confirm_spawn = false;
 static bool arg_show_status = true;
 static bool arg_switched_root = false;
 static char **arg_default_controllers = NULL;
+static char *arg_default_oom_score = NULL;
 static char ***arg_join_controllers = NULL;
 static ExecOutput arg_default_std_output = EXEC_OUTPUT_JOURNAL;
 static ExecOutput arg_default_std_error = EXEC_OUTPUT_INHERIT;
@@ -641,6 +642,7 @@ static int parse_config_file(void) {
                 { "Manager", "DefaultStandardOutput", config_parse_output,       0, &arg_default_std_output  },
                 { "Manager", "DefaultStandardError",  config_parse_output,       0, &arg_default_std_error   },
                 { "Manager", "JoinControllers",       config_parse_join_controllers, 0, &arg_join_controllers },
+                { "Manager", "DefaultOOMScore",       config_parse_string,       0, &arg_default_oom_score   },
                 { "Manager", "RuntimeWatchdogSec",    config_parse_sec,          0, &arg_runtime_watchdog    },
                 { "Manager", "ShutdownWatchdogSec",   config_parse_sec,          0, &arg_shutdown_watchdog   },
                 { "Manager", "CapabilityBoundingSet", config_parse_bounding_set, 0, &arg_capability_bounding_set_drop },
@@ -1414,6 +1416,12 @@ int main(int argc, char *argv[]) {
         if (parse_config_file() < 0)
                 goto finish;
 
+        if (arg_default_oom_score)
+                if (write_string_file("/proc/self/oom_score_adj", arg_default_oom_score) < 0){
+                        log_error("Fail to set default oom_score_adj: %s", arg_default_oom_score);
+                        goto finish;
+                }
+
         if (arg_running_as == SYSTEMD_SYSTEM)
                 if (parse_proc_cmdline() < 0)
                         goto finish;
diff --git a/src/core/system.conf b/src/core/system.conf
index 508e0f5..7c0e12e 100644
--- a/src/core/system.conf
+++ b/src/core/system.conf
@@ -41,3 +41,4 @@
 #DefaultLimitNICE=
 #DefaultLimitRTPRIO=
 #DefaultLimitRTTIME=
+#DefaultOOMScore=
diff --git a/src/core/user.conf b/src/core/user.conf
index 4252451..f101e99 100644
--- a/src/core/user.conf
+++ b/src/core/user.conf
@@ -15,3 +15,4 @@
 #DefaultControllers=cpu
 #DefaultStandardOutput=inherit
 #DefaultStandardError=inherit
+#DefaultOOMScore=
-- 
1.7.10.4