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

1 files changed, 1 insertions, 0 deletions

diff --git a/src/login/logind.h b/src/login/logind.h
index 56dd515f6..41b48ef74 100644
--- a/src/login/logind.h
+++ b/src/login/logind.h
@@ -229,6 +229,7 @@ const struct ConfigPerfItem* logind_gperf_lookup(const char *key, GPERF_LEN_TYPE
 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);