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authorLennart Poettering <lennart@poettering.net>2016-07-19 17:19:58 +0200
committerLennart Poettering <lennart@poettering.net>2016-07-22 15:33:13 +0200
commitc06eec15d5816236c11e35b35e444f62f37b6ef6 (patch)
treedf56cc996e476aeff44fc01e4d32432fc9178051
parent84af7821b65ad11417ac2984717cf42a3655fcd7 (diff)
logind: change TasksMax= value for user logins to 33%
Let's change from a fixed value of 12288 tasks per user to a relative value of 33%, which with the kernel's default of 32768 translates to 10813. This is a slight decrease of the limit, for no other reason than "33%" sounding like a nice round number that is close enough to 12288 (which would translate to 37.5%). (Well, it also has the nice effect of still leaving a bit of room in the PID space if there are 3 cooperating evil users that try to consume all PIDs... Also, I like my bikesheds blue). Since the new value is taken relative, and machined's TasksMax= setting defaults to 16384, 33% inside of containers is usually equivalent to 5406, which should still be ample space. To summarize: | on the host | in the container old default | 12288 | 12288 new default | 10813 | 5406
-rw-r--r--man/logind.conf.xml9
-rw-r--r--src/login/logind-gperf.gperf2
-rw-r--r--src/login/logind-user.c45
-rw-r--r--src/login/logind.c2
-rw-r--r--src/login/logind.conf.in2
-rw-r--r--src/login/logind.h1
6 files changed, 53 insertions, 8 deletions
diff --git a/man/logind.conf.xml b/man/logind.conf.xml
index fe92277a1f..adba5a4131 100644
--- a/man/logind.conf.xml
+++ b/man/logind.conf.xml
@@ -315,12 +315,11 @@
<varlistentry>
<term><varname>UserTasksMax=</varname></term>
- <listitem><para>Sets the maximum number of OS tasks each user
- may run concurrently. This controls the
- <varname>TasksMax=</varname> setting of the per-user slice
- unit, see
+ <listitem><para>Sets the maximum number of OS tasks each user may run concurrently. This controls the
+ <varname>TasksMax=</varname> setting of the per-user slice unit, see
<citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>
- for details. Defaults to 12288 (12K).</para></listitem>
+ for details. Defaults to 33%, which equals 10813 with the kernel's defaults on the host, but might be smaller
+ in OS containers.</para></listitem>
</varlistentry>
<varlistentry>
diff --git a/src/login/logind-gperf.gperf b/src/login/logind-gperf.gperf
index 6bd08adc05..0b6a5f3cf4 100644
--- a/src/login/logind-gperf.gperf
+++ b/src/login/logind-gperf.gperf
@@ -36,4 +36,4 @@ Login.RuntimeDirectorySize, config_parse_tmpfs_size, 0, offsetof(Manag
Login.RemoveIPC, config_parse_bool, 0, offsetof(Manager, remove_ipc)
Login.InhibitorsMax, config_parse_uint64, 0, offsetof(Manager, inhibitors_max)
Login.SessionsMax, config_parse_uint64, 0, offsetof(Manager, sessions_max)
-Login.UserTasksMax, config_parse_uint64, 0, offsetof(Manager, user_tasks_max)
+Login.UserTasksMax, config_parse_user_tasks_max,0, offsetof(Manager, user_tasks_max)
diff --git a/src/login/logind-user.c b/src/login/logind-user.c
index de44d369cf..f7d83909a0 100644
--- a/src/login/logind-user.c
+++ b/src/login/logind-user.c
@@ -870,3 +870,48 @@ int config_parse_tmpfs_size(
return 0;
}
+
+int config_parse_user_tasks_max(
+ const char* unit,
+ const char *filename,
+ unsigned line,
+ const char *section,
+ unsigned section_line,
+ const char *lvalue,
+ int ltype,
+ const char *rvalue,
+ void *data,
+ void *userdata) {
+
+ uint64_t *m = data;
+ uint64_t k;
+ int r;
+
+ assert(filename);
+ assert(lvalue);
+ assert(rvalue);
+ assert(data);
+
+ /* First, try to parse as percentage */
+ r = parse_percent(rvalue);
+ if (r > 0 && r < 100)
+ k = system_tasks_max_scale(r, 100U);
+ else {
+
+ /* If the passed argument was not a percentage, or out of range, parse as byte size */
+
+ r = safe_atou64(rvalue, &k);
+ if (r < 0) {
+ log_syntax(unit, LOG_ERR, filename, line, r, "Failed to parse tasks maximum, ignoring: %s", rvalue);
+ return 0;
+ }
+ }
+
+ if (k <= 0 || k >= UINT64_MAX) {
+ log_syntax(unit, LOG_ERR, filename, line, 0, "Tasks maximum out of range, ignoring: %s", rvalue);
+ return 0;
+ }
+
+ *m = k;
+ return 0;
+}
diff --git a/src/login/logind.c b/src/login/logind.c
index d01dd110ea..5ce36d28c7 100644
--- a/src/login/logind.c
+++ b/src/login/logind.c
@@ -62,7 +62,7 @@ static void manager_reset_config(Manager *m) {
m->idle_action = HANDLE_IGNORE;
m->runtime_dir_size = physical_memory_scale(10U, 100U); /* 10% */
- m->user_tasks_max = 12288;
+ m->user_tasks_max = system_tasks_max_scale(33U, 100U); /* 33% */
m->sessions_max = 8192;
m->inhibitors_max = 8192;
diff --git a/src/login/logind.conf.in b/src/login/logind.conf.in
index 32c0844cb6..6f720b7708 100644
--- a/src/login/logind.conf.in
+++ b/src/login/logind.conf.in
@@ -34,4 +34,4 @@
#RemoveIPC=yes
#InhibitorsMax=8192
#SessionsMax=8192
-#UserTasksMax=12288
+#UserTasksMax=33%
diff --git a/src/login/logind.h b/src/login/logind.h
index 90431eb4b0..086fa1eeb5 100644
--- a/src/login/logind.h
+++ b/src/login/logind.h
@@ -187,6 +187,7 @@ const struct ConfigPerfItem* logind_gperf_lookup(const char *key, unsigned lengt
int manager_set_lid_switch_ignore(Manager *m, usec_t until);
int config_parse_tmpfs_size(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
+int config_parse_user_tasks_max(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
int manager_get_session_from_creds(Manager *m, sd_bus_message *message, const char *name, sd_bus_error *error, Session **ret);
int manager_get_user_from_creds(Manager *m, sd_bus_message *message, uid_t uid, sd_bus_error *error, User **ret);