diff options
| -rw-r--r-- | man/systemd.exec.xml | 38 | ||||
| -rw-r--r-- | src/basic/rlimit-util.c | 52 | ||||
| -rw-r--r-- | src/test/test-rlimit-util.c | 12 |
3 files changed, 80 insertions, 22 deletions
diff --git a/man/systemd.exec.xml b/man/systemd.exec.xml index 2d0fb63f1d..2a93760428 100644 --- a/man/systemd.exec.xml +++ b/man/systemd.exec.xml @@ -629,27 +629,23 @@ <term><varname>LimitNICE=</varname></term> <term><varname>LimitRTPRIO=</varname></term> <term><varname>LimitRTTIME=</varname></term> - <listitem><para>These settings set both soft and hard limits - of various resources for executed processes. See - <citerefentry><refentrytitle>setrlimit</refentrytitle><manvolnum>2</manvolnum></citerefentry> - for details. The resource limit is possible to specify in two formats, - <option>value</option> to set soft and hard limits to the same value, - or <option>soft:hard</option> to set both limits individually (e.g. LimitAS=4G:16G). - Use the string <varname>infinity</varname> to - configure no limit on a specific resource. The multiplicative - suffixes K (=1024), M (=1024*1024) and so on for G, T, P and E - may be used for resource limits measured in bytes - (e.g. LimitAS=16G). For the limits referring to time values, - the usual time units ms, s, min, h and so on may be used (see - <citerefentry><refentrytitle>systemd.time</refentrytitle><manvolnum>7</manvolnum></citerefentry> - for details). Note that if no time unit is specified for - <varname>LimitCPU=</varname> the default unit of seconds is - implied, while for <varname>LimitRTTIME=</varname> the default - unit of microseconds is implied. Also, note that the effective - granularity of the limits might influence their - enforcement. For example, time limits specified for - <varname>LimitCPU=</varname> will be rounded up implicitly to - multiples of 1s.</para> + <listitem><para>Set soft and hard limits on various resources for executed processes. See + <citerefentry><refentrytitle>setrlimit</refentrytitle><manvolnum>2</manvolnum></citerefentry> for details on + the resource limit concept. Resource limits may be specified in two formats: either as single value to set a + specific soft and hard limit to the same value, or as colon-separated pair <option>soft:hard</option> to set + both limits individually (e.g. <literal>LimitAS=4G:16G</literal>). Use the string <varname>infinity</varname> + to configure no limit on a specific resource. The multiplicative suffixes K, M, G, T, P and E (to the base + 1024) may be used for resource limits measured in bytes (e.g. LimitAS=16G). For the limits referring to time + values, the usual time units ms, s, min, h and so on may be used (see + <citerefentry><refentrytitle>systemd.time</refentrytitle><manvolnum>7</manvolnum></citerefentry> for + details). Note that if no time unit is specified for <varname>LimitCPU=</varname> the default unit of seconds + is implied, while for <varname>LimitRTTIME=</varname> the default unit of microseconds is implied. Also, note + that the effective granularity of the limits might influence their enforcement. For example, time limits + specified for <varname>LimitCPU=</varname> will be rounded up implicitly to multiples of 1s. For + <varname>LimitNICE=</varname> the value may be specified in two syntaxes: if prefixed with <literal>+</literal> + or <literal>-</literal>, the value is understood as regular Linux nice value in the range -20..19. If not + prefixed like this the value is understood as raw resource limit parameter in the range 0..40 (with 0 being + equivalent to 1).</para> <para>Note that most process resource limits configured with these options are per-process, and processes may fork in order diff --git a/src/basic/rlimit-util.c b/src/basic/rlimit-util.c index 7540b43215..ee063720ed 100644 --- a/src/basic/rlimit-util.c +++ b/src/basic/rlimit-util.c @@ -153,6 +153,56 @@ static int rlimit_parse_usec(const char *val, rlim_t *ret) { return 0; } +static int rlimit_parse_nice(const char *val, rlim_t *ret) { + uint64_t rl; + int r; + + /* So, Linux is weird. The range for RLIMIT_NICE is 40..1, mapping to the nice levels -20..19. However, the + * RLIMIT_NICE limit defaults to 0 by the kernel, i.e. a value that maps to nice level 20, which of course is + * bogus and does not exist. In order to permit parsing the RLIMIT_NICE of 0 here we hence implement a slight + * asymmetry: when parsing as positive nice level we permit 0..19. When parsing as negative nice level, we + * permit -20..0. But when parsing as raw resource limit value then we also allow the special value 0. + * + * Yeah, Linux is quality engineering sometimes... */ + + if (val[0] == '+') { + + /* Prefixed with "+": Parse as positive user-friendly nice value */ + r = safe_atou64(val + 1, &rl); + if (r < 0) + return r; + + if (rl >= PRIO_MAX) + return -ERANGE; + + rl = 20 - rl; + + } else if (val[0] == '-') { + + /* Prefixed with "-": Parse as negative user-friendly nice value */ + r = safe_atou64(val + 1, &rl); + if (r < 0) + return r; + + if (rl > (uint64_t) (-PRIO_MIN)) + return -ERANGE; + + rl = 20 + rl; + } else { + + /* Not prefixed: parse as raw resource limit value */ + r = safe_atou64(val, &rl); + if (r < 0) + return r; + + if (rl > (uint64_t) (20 - PRIO_MIN)) + return -ERANGE; + } + + *ret = (rlim_t) rl; + return 0; +} + static int (*const rlimit_parse_table[_RLIMIT_MAX])(const char *val, rlim_t *ret) = { [RLIMIT_CPU] = rlimit_parse_sec, [RLIMIT_FSIZE] = rlimit_parse_size, @@ -167,7 +217,7 @@ static int (*const rlimit_parse_table[_RLIMIT_MAX])(const char *val, rlim_t *ret [RLIMIT_LOCKS] = rlimit_parse_u64, [RLIMIT_SIGPENDING] = rlimit_parse_u64, [RLIMIT_MSGQUEUE] = rlimit_parse_size, - [RLIMIT_NICE] = rlimit_parse_u64, + [RLIMIT_NICE] = rlimit_parse_nice, [RLIMIT_RTPRIO] = rlimit_parse_u64, [RLIMIT_RTTIME] = rlimit_parse_usec, }; diff --git a/src/test/test-rlimit-util.c b/src/test/test-rlimit-util.c index d9ac9368cd..62afd2de5e 100644 --- a/src/test/test-rlimit-util.c +++ b/src/test/test-rlimit-util.c @@ -99,6 +99,18 @@ int main(int argc, char *argv[]) { test_rlimit_parse_format(RLIMIT_NOFILE, "", 0, 0, -EINVAL, NULL); test_rlimit_parse_format(RLIMIT_NOFILE, "5:4", 0, 0, -EILSEQ, NULL); test_rlimit_parse_format(RLIMIT_NOFILE, "5:4:3", 0, 0, -EINVAL, NULL); + test_rlimit_parse_format(RLIMIT_NICE, "20", 20, 20, 0, "20"); + test_rlimit_parse_format(RLIMIT_NICE, "40", 40, 40, 0, "40"); + test_rlimit_parse_format(RLIMIT_NICE, "41", 41, 41, -ERANGE, "41"); + test_rlimit_parse_format(RLIMIT_NICE, "0", 0, 0, 0, "0"); + test_rlimit_parse_format(RLIMIT_NICE, "-7", 27, 27, 0, "27"); + test_rlimit_parse_format(RLIMIT_NICE, "-20", 40, 40, 0, "40"); + test_rlimit_parse_format(RLIMIT_NICE, "-21", 41, 41, -ERANGE, "41"); + test_rlimit_parse_format(RLIMIT_NICE, "-0", 20, 20, 0, "20"); + test_rlimit_parse_format(RLIMIT_NICE, "+7", 13, 13, 0, "13"); + test_rlimit_parse_format(RLIMIT_NICE, "+19", 1, 1, 0, "1"); + test_rlimit_parse_format(RLIMIT_NICE, "+20", 0, 0, -ERANGE, "0"); + test_rlimit_parse_format(RLIMIT_NICE, "+0", 20, 20, 0, "20"); return 0; } |