From c06eec15d5816236c11e35b35e444f62f37b6ef6 Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Tue, 19 Jul 2016 17:19:58 +0200 Subject: 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 --- src/login/logind-user.c | 45 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) (limited to 'src/login/logind-user.c') 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; +} -- cgit v1.2.3-54-g00ecf