[Freeipa-users] ns-slapd using all CPU ressources

[Domingues Luis Filipe]

Hi all,

On our infra, we have two machines running Fedora with FreeIPA installed.

we have an issue with ns-slapd using 100% of CPU after a while. If we restart the service, it starts to use all CPU resources after one day.

Outpute of the command strace -c -p <ns-slapd PID> running for 4 minutes is:


% time     seconds  usecs/call     calls    errors syscall
------ ----------- ----------- --------- --------- ----------------
 99.80  229.603633       11247     20415           poll
  0.15    0.340032          10     32983         4 futex
  0.05    0.114068      114068         1           restart_syscall
  0.00    0.003464           0     20420     20416 getpeername
  0.00    0.002752           0     20416           clock_gettime
  0.00    0.001920           0      9840           read
  0.00    0.000205           5        45           close
  0.00    0.000036           2        22           access
  0.00    0.000017           1        22           open
  0.00    0.000016           1        24           accept
  0.00    0.000012           0        45           setsockopt
  0.00    0.000007           0        22           fstat
  0.00    0.000000           0        22           stat
  0.00    0.000000           0         1           sendto
  0.00    0.000000           0        24           getsockname
  0.00    0.000000           0         4           getsockopt
  0.00    0.000000           0        70           fcntl
  0.00    0.000000           0        22           gettimeofday
------ ----------- ----------- --------- --------- ----------------
100.00  230.066162                104398     20420 total


Plus we looked at the syscalls using FTrace:


ns-slapd-7963  [000] .... 4063846.395630: sys_sched_yield()
ns-slapd-7956  [000] .... 4063846.395631: sys_sched_yield -> 0x0
ns-slapd-7956  [000] .... 4063846.395632: sys_sched_yield()
ns-slapd-7973  [000] .... 4063846.395633: sys_sched_yield -> 0x0
ns-slapd-7973  [000] .... 4063846.395634: sys_sched_yield()
ns-slapd-7965  [000] .... 4063846.395635: sys_sched_yield -> 0x0
ns-slapd-7965  [000] .... 4063846.395637: sys_sched_yield()
ns-slapd-7963  [000] .... 4063846.395637: sys_sched_yield -> 0x0
ns-slapd-7963  [000] .... 4063846.395639: sys_sched_yield()
ns-slapd-7956  [000] .... 4063846.395640: sys_sched_yield -> 0x0
ns-slapd-7956  [000] .... 4063846.395641: sys_sched_yield()
ns-slapd-7973  [000] .... 4063846.395642: sys_sched_yield -> 0x0
ns-slapd-7973  [000] .... 4063846.395643: sys_sched_yield()
ns-slapd-7965  [000] .... 4063846.395644: sys_sched_yield -> 0x0

The sys_sched_yield function is called almost every 2 microseconds. It seems too much.

Anyone have an idea where this can come from? Bad configuration on our side or some bug on ns-slapd?

Regards,
Luis Domingues
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