[Touch-packages] [Bug 1629226] Re: systemd's service killed by cgroup controller pids
Regarding the original report this is a simple program which keeps the maximal
allowed children running and it does not get killed by cgroups, just the fork()
call fails:
---
#include
#include
#include
#include
#include
#include
#include
#include
#define MASTER_SLEEP_NS 100L
#define CHILD_SLEEP_S 5
void main(void)
{
pid_t pid;
struct timespec master_sleep = {0, MASTER_SLEEP_NS};
for (;;) {
pid = fork();
if (pid < 0) {
perror("fork failed:");
nanosleep(_sleep, NULL);
}
if (pid == 0) {
sleep(CHILD_SLEEP_S);
exit(0);
}
nanosleep(_sleep, NULL);
/* collect exited children */
while (waitpid(-1, NULL, WNOHANG) > 0);
}
}
---
[Unit]
Description=Reproducer
After=multi-user.target
[Service]
ExecStart=/home/user/reproducer
Type=simple
TasksMax=512
[Install]
WantedBy=multi-user.target
---
● reproducer.service - Reproducer
Loaded: loaded (/etc/systemd/system/reproducer.service; disabled; vendor
preset: enabled)
Active: active (running) since Mon 2017-05-22 13:16:50 UTC; 3min 3s ago
Main PID: 11778 (reproducer)
Tasks: 512 (limit: 512)
Memory: 55.4M
CPU: 1min 2.794s
CGroup: /system.slice/reproducer.service
├─11778 /home/rbalint/reproducer
├─18144 /home/rbalint/reproducer
...
├─26763 /home/rbalint/reproducer
├─26764 /home/rbalint/reproducer
├─26765 /home/rbalint/reproducer
└─26766 /home/rbalint/reproducer
May 22 13:20:14 zesty-test reproducer[11778]: fork failed:: Resource
temporarily unavailable
May 22 13:20:14 zesty-test reproducer[11778]: fork failed:: Resource
temporarily unavailable
May 22 13:20:14 zesty-test reproducer[11778]: fork failed:: Resource
temporarily unavailable
---
Bash on the other hand kills itself after a few failing forks:
● reproducer.service - Reproducer
Loaded: loaded (/etc/systemd/system/reproducer.service; disabled; vendor
preset: enabled)
Active: failed (Result: exit-code) since Mon 2017-05-22 13:22:38 UTC; 3s ago
Process: 14281 ExecStart=/home/rbalint/reproducer.sh (code=exited,
status=0/SUCCESS)
Main PID: 14287 (code=exited, status=254)
CPU: 639ms
May 22 13:22:35 zesty-test reproducer.sh[14281]: /home/rbalint/reproducer.sh:
fork: retry: Resource temporarily unavailable
May 22 13:22:35 zesty-test reproducer.sh[14281]: /home/rbalint/reproducer.sh:
fork: retry: Resource temporarily unavailable
May 22 13:22:35 zesty-test reproducer.sh[14281]: /home/rbalint/reproducer.sh:
fork: retry: Resource temporarily unavailable
May 22 13:22:35 zesty-test reproducer.sh[14281]: /home/rbalint/reproducer.sh:
fork: retry: Resource temporarily unavailable
May 22 13:22:35 zesty-test reproducer.sh[14281]: /home/rbalint/reproducer.sh:
fork: retry: Resource temporarily unavailable
May 22 13:22:35 zesty-test reproducer.sh[14281]: /home/rbalint/reproducer.sh:
fork: retry: Resource temporarily unavailable
May 22 13:22:38 zesty-test reproducer.sh[14281]: /home/rbalint/reproducer.sh:
fork: Interrupted system call
May 22 13:22:38 zesty-test systemd[1]: reproducer.service: Main process exited,
code=exited, status=254/n/a
May 22 13:22:38 zesty-test systemd[1]: reproducer.service: Unit entered failed
state.
http://sources.debian.net/src/bash/4.4-5/jobs.c/?hl=1919#L1919
/* Create the child, handle severe errors. Retry on EAGAIN. */
while ((pid = fork ()) < 0 && errno == EAGAIN && forksleep < FORKSLEEP_MAX)
{
/* bash-4.2 */
sigprocmask (SIG_SETMASK, , (sigset_t *)NULL);
/* If we can't create any children, try to reap some dead ones. */
waitchld (-1, 0);
errno = EAGAIN; /* restore errno */
sys_error ("fork: retry");
RESET_SIGTERM;
if (sleep (forksleep) != 0)
break;
forksleep <<= 1;
if (interrupt_state)
break;
sigprocmask (SIG_SETMASK, , (sigset_t *)NULL);
}
...
if (pid < 0)
{
sys_error ("fork");
/* Kill all of the processes in the current pipeline. */
terminate_current_pipeline ();
/* Discard the current pipeline, if any. */
if (the_pipeline)
kill_current_pipeline ();
last_command_exit_value = EX_NOEXEC;
throw_to_top_level ();/* Reset signals, etc. */
}
...
I believe this is by design and I think this approach is reasonable.
A shell should not try to keep itself alive forking new processes when
it hit system limits already for a few times. There are other tools
available for implementing servers with worker pools which adapt to
system limits which are not defined in advance.
If you know the number of workers need in advance I suggest setting
TasksMax to high enough or to infinity in case you don't want to rely on
cgroup fork limits.
** Changed in: bash (Ubuntu)
Status: In Progress => Invalid
** Summary changed:
- systemd's service killed by cgroup controller pids
+ Bash exits after a few failed fork()-s
--
You received this bug
[Touch-packages] [Bug 1629226] Re: systemd's service killed by cgroup controller pids
** Changed in: bash (Ubuntu)
Status: Triaged => In Progress
--
You received this bug notification because you are a member of Ubuntu
Touch seeded packages, which is subscribed to bash in Ubuntu.
https://bugs.launchpad.net/bugs/1629226
Title:
systemd's service killed by cgroup controller pids
Status in The Ubuntu-power-systems project:
New
Status in bash package in Ubuntu:
In Progress
Bug description:
Problem Description
===
I write a simple systemd service which will fork child processes fiercely.
But quickly the service failed:
% sudo systemctl status reproducer.service
? reproducer.service - Reproducer of systemd services killed by ips
Loaded: loaded (/etc/systemd/system/reproducer.service; disabled; vendor
preset: enabled)
Active: failed (Result: exit-code) since Fri 2016-03-18 06:58:37 CDT; 2min
43s ago
Process: 5103 ExecStart=/home/hpt/reproducer/reproducer.sh (code=exited,
status=0/SUCCESS)
Main PID: 5105 (code=exited, status=254)
Mar 18 06:58:36 pinelp3 reproducer.sh[5103]:
/home/hpt/reproducer/reproducer.sh: fork: Resource temporarily unavailable
Mar 18 06:58:36 pinelp3 reproducer.sh[5103]:
/home/hpt/reproducer/reproducer.sh: fork: Resource temporarily unavailable
Mar 18 06:58:37 pinelp3 reproducer.sh[5103]:
/home/hpt/reproducer/reproducer.sh: fork: Resource temporarily unavailable
Mar 18 06:58:37 pinelp3 reproducer.sh[5103]:
/home/hpt/reproducer/reproducer.sh: fork: Resource temporarily unavailable
Mar 18 06:58:37 pinelp3 reproducer.sh[5103]:
/home/hpt/reproducer/reproducer.sh: fork: Resource temporarily unavailable
Mar 18 06:58:37 pinelp3 reproducer.sh[5103]:
/home/hpt/reproducer/reproducer.sh: fork: Resource temporarily unavailable
Mar 18 06:58:37 pinelp3 systemd[1]: reproducer.service: Main process exited,
code=exited, status=254/n/a
Mar 18 06:58:37 pinelp3 reproducer.sh[5103]:
/home/hpt/reproducer/reproducer.sh: fork: Resource temporarily unavailable
Mar 18 06:58:37 pinelp3 systemd[1]: reproducer.service: Unit entered failed
state.
Mar 18 06:58:37 pinelp3 systemd[1]: reproducer.service: Failed with result
'exit-code'.
The default task limit of systemd services is 512. Looks like the
service is terminated by the kernel's ips cgroup controller. I think
this isn't correct. Child processes cannot be forked shouldn't cause
parent to die.
% cat /etc/systemd/system/reproducer.service
[Unit]
Description=Reproducer of systemd services killed by ips
After=multi-user.target
[Service]
ExecStart=/home/hpt/reproducer/reproducer.sh
Type=forking
[Install]
WantedBy=multi-user.target
% cat /home/hpt/reproducer/reproducer.sh
#!/bin/bash
foo()
{
#exec sh -c "echo $1: \$\$;sleep 60"
echo $1:
sleep 60
}
bar()
{
c=1
while true
do
for ((i=1;i<=2048;i++))
do
foo $c &
((c++))
done
wait
c=1
done
}
# main
bar &
disown -a
exit 0
---uname output---
Linux pinelp3 4.4.0-12-generic #28-Ubuntu SMP Wed Mar 9 00:40:38 UTC 2016
ppc64le ppc64le ppc64le GNU/Linux
Machine Type = IBM,8408-E8E,lpar
Steps to Reproduce
1. install the simple service in "Problem description"
2. sudo systemctl start reproducer.service
3. wait 2~3 minutes
== Comment: #3 - Vaishnavi Bhat - 2016-03-22 11:21:55 ==
From the machine,
root@pinelp3:~# ulimit -a
core file size (blocks, -c) 0
data seg size (kbytes, -d) unlimited
scheduling priority (-e) 0
file size (blocks, -f) unlimited
pending signals (-i) 48192
max locked memory (kbytes, -l) 64
max memory size (kbytes, -m) unlimited
open files (-n) 1024
pipe size(512 bytes, -p) 8
POSIX message queues (bytes, -q) 819200
real-time priority (-r) 0
stack size (kbytes, -s) 8192
cpu time (seconds, -t) unlimited
max user processes (-u) 48192
virtual memory (kbytes, -v) unlimited
file locks (-x) unlimited
root@pinelp3:~# ps aux | wc -l ->While the service is
running
1084
root@pinelp3:~# ps aux | wc -l "
1084
root@pinelp3:~# ps aux | wc -l "
1084
root@pinelp3:~# ps aux | wc -l "
1084
root@pinelp3:~# ps aux | wc -l-->While the service is not
running.
572
root@pinelp3:~# free -m --> While service is running
totalusedfree shared buff/cache
available
Mem: 12117 628 459 22 11029
[Touch-packages] [Bug 1629226] Re: systemd's service killed by cgroup controller pids
** Changed in: bash (Ubuntu)
Importance: Undecided => Medium
** Changed in: bash (Ubuntu)
Status: New => Triaged
** Changed in: bash (Ubuntu)
Milestone: None => ubuntu-17.05
** Changed in: bash (Ubuntu)
Assignee: Taco Screen team (taco-screen-team) => Balint Reczey (rbalint)
--
You received this bug notification because you are a member of Ubuntu
Touch seeded packages, which is subscribed to bash in Ubuntu.
https://bugs.launchpad.net/bugs/1629226
Title:
systemd's service killed by cgroup controller pids
Status in The Ubuntu-power-systems project:
New
Status in bash package in Ubuntu:
Triaged
Bug description:
Problem Description
===
I write a simple systemd service which will fork child processes fiercely.
But quickly the service failed:
% sudo systemctl status reproducer.service
? reproducer.service - Reproducer of systemd services killed by ips
Loaded: loaded (/etc/systemd/system/reproducer.service; disabled; vendor
preset: enabled)
Active: failed (Result: exit-code) since Fri 2016-03-18 06:58:37 CDT; 2min
43s ago
Process: 5103 ExecStart=/home/hpt/reproducer/reproducer.sh (code=exited,
status=0/SUCCESS)
Main PID: 5105 (code=exited, status=254)
Mar 18 06:58:36 pinelp3 reproducer.sh[5103]:
/home/hpt/reproducer/reproducer.sh: fork: Resource temporarily unavailable
Mar 18 06:58:36 pinelp3 reproducer.sh[5103]:
/home/hpt/reproducer/reproducer.sh: fork: Resource temporarily unavailable
Mar 18 06:58:37 pinelp3 reproducer.sh[5103]:
/home/hpt/reproducer/reproducer.sh: fork: Resource temporarily unavailable
Mar 18 06:58:37 pinelp3 reproducer.sh[5103]:
/home/hpt/reproducer/reproducer.sh: fork: Resource temporarily unavailable
Mar 18 06:58:37 pinelp3 reproducer.sh[5103]:
/home/hpt/reproducer/reproducer.sh: fork: Resource temporarily unavailable
Mar 18 06:58:37 pinelp3 reproducer.sh[5103]:
/home/hpt/reproducer/reproducer.sh: fork: Resource temporarily unavailable
Mar 18 06:58:37 pinelp3 systemd[1]: reproducer.service: Main process exited,
code=exited, status=254/n/a
Mar 18 06:58:37 pinelp3 reproducer.sh[5103]:
/home/hpt/reproducer/reproducer.sh: fork: Resource temporarily unavailable
Mar 18 06:58:37 pinelp3 systemd[1]: reproducer.service: Unit entered failed
state.
Mar 18 06:58:37 pinelp3 systemd[1]: reproducer.service: Failed with result
'exit-code'.
The default task limit of systemd services is 512. Looks like the
service is terminated by the kernel's ips cgroup controller. I think
this isn't correct. Child processes cannot be forked shouldn't cause
parent to die.
% cat /etc/systemd/system/reproducer.service
[Unit]
Description=Reproducer of systemd services killed by ips
After=multi-user.target
[Service]
ExecStart=/home/hpt/reproducer/reproducer.sh
Type=forking
[Install]
WantedBy=multi-user.target
% cat /home/hpt/reproducer/reproducer.sh
#!/bin/bash
foo()
{
#exec sh -c "echo $1: \$\$;sleep 60"
echo $1:
sleep 60
}
bar()
{
c=1
while true
do
for ((i=1;i<=2048;i++))
do
foo $c &
((c++))
done
wait
c=1
done
}
# main
bar &
disown -a
exit 0
---uname output---
Linux pinelp3 4.4.0-12-generic #28-Ubuntu SMP Wed Mar 9 00:40:38 UTC 2016
ppc64le ppc64le ppc64le GNU/Linux
Machine Type = IBM,8408-E8E,lpar
Steps to Reproduce
1. install the simple service in "Problem description"
2. sudo systemctl start reproducer.service
3. wait 2~3 minutes
== Comment: #3 - Vaishnavi Bhat - 2016-03-22 11:21:55 ==
From the machine,
root@pinelp3:~# ulimit -a
core file size (blocks, -c) 0
data seg size (kbytes, -d) unlimited
scheduling priority (-e) 0
file size (blocks, -f) unlimited
pending signals (-i) 48192
max locked memory (kbytes, -l) 64
max memory size (kbytes, -m) unlimited
open files (-n) 1024
pipe size(512 bytes, -p) 8
POSIX message queues (bytes, -q) 819200
real-time priority (-r) 0
stack size (kbytes, -s) 8192
cpu time (seconds, -t) unlimited
max user processes (-u) 48192
virtual memory (kbytes, -v) unlimited
file locks (-x) unlimited
root@pinelp3:~# ps aux | wc -l ->While the service is
running
1084
root@pinelp3:~# ps aux | wc -l "
1084
root@pinelp3:~# ps aux | wc -l "
1084
root@pinelp3:~# ps aux | wc -l "
1084
root@pinelp3:~# ps aux | wc -l-->While the service is not
running.
572
[Touch-packages] [Bug 1629226] Re: systemd's service killed by cgroup controller pids
** Also affects: ubuntu-power-systems
Importance: Undecided
Status: New
--
You received this bug notification because you are a member of Ubuntu
Touch seeded packages, which is subscribed to bash in Ubuntu.
https://bugs.launchpad.net/bugs/1629226
Title:
systemd's service killed by cgroup controller pids
Status in The Ubuntu-power-systems project:
New
Status in bash package in Ubuntu:
New
Bug description:
Problem Description
===
I write a simple systemd service which will fork child processes fiercely.
But quickly the service failed:
% sudo systemctl status reproducer.service
? reproducer.service - Reproducer of systemd services killed by ips
Loaded: loaded (/etc/systemd/system/reproducer.service; disabled; vendor
preset: enabled)
Active: failed (Result: exit-code) since Fri 2016-03-18 06:58:37 CDT; 2min
43s ago
Process: 5103 ExecStart=/home/hpt/reproducer/reproducer.sh (code=exited,
status=0/SUCCESS)
Main PID: 5105 (code=exited, status=254)
Mar 18 06:58:36 pinelp3 reproducer.sh[5103]:
/home/hpt/reproducer/reproducer.sh: fork: Resource temporarily unavailable
Mar 18 06:58:36 pinelp3 reproducer.sh[5103]:
/home/hpt/reproducer/reproducer.sh: fork: Resource temporarily unavailable
Mar 18 06:58:37 pinelp3 reproducer.sh[5103]:
/home/hpt/reproducer/reproducer.sh: fork: Resource temporarily unavailable
Mar 18 06:58:37 pinelp3 reproducer.sh[5103]:
/home/hpt/reproducer/reproducer.sh: fork: Resource temporarily unavailable
Mar 18 06:58:37 pinelp3 reproducer.sh[5103]:
/home/hpt/reproducer/reproducer.sh: fork: Resource temporarily unavailable
Mar 18 06:58:37 pinelp3 reproducer.sh[5103]:
/home/hpt/reproducer/reproducer.sh: fork: Resource temporarily unavailable
Mar 18 06:58:37 pinelp3 systemd[1]: reproducer.service: Main process exited,
code=exited, status=254/n/a
Mar 18 06:58:37 pinelp3 reproducer.sh[5103]:
/home/hpt/reproducer/reproducer.sh: fork: Resource temporarily unavailable
Mar 18 06:58:37 pinelp3 systemd[1]: reproducer.service: Unit entered failed
state.
Mar 18 06:58:37 pinelp3 systemd[1]: reproducer.service: Failed with result
'exit-code'.
The default task limit of systemd services is 512. Looks like the
service is terminated by the kernel's ips cgroup controller. I think
this isn't correct. Child processes cannot be forked shouldn't cause
parent to die.
% cat /etc/systemd/system/reproducer.service
[Unit]
Description=Reproducer of systemd services killed by ips
After=multi-user.target
[Service]
ExecStart=/home/hpt/reproducer/reproducer.sh
Type=forking
[Install]
WantedBy=multi-user.target
% cat /home/hpt/reproducer/reproducer.sh
#!/bin/bash
foo()
{
#exec sh -c "echo $1: \$\$;sleep 60"
echo $1:
sleep 60
}
bar()
{
c=1
while true
do
for ((i=1;i<=2048;i++))
do
foo $c &
((c++))
done
wait
c=1
done
}
# main
bar &
disown -a
exit 0
---uname output---
Linux pinelp3 4.4.0-12-generic #28-Ubuntu SMP Wed Mar 9 00:40:38 UTC 2016
ppc64le ppc64le ppc64le GNU/Linux
Machine Type = IBM,8408-E8E,lpar
Steps to Reproduce
1. install the simple service in "Problem description"
2. sudo systemctl start reproducer.service
3. wait 2~3 minutes
== Comment: #3 - Vaishnavi Bhat - 2016-03-22 11:21:55 ==
From the machine,
root@pinelp3:~# ulimit -a
core file size (blocks, -c) 0
data seg size (kbytes, -d) unlimited
scheduling priority (-e) 0
file size (blocks, -f) unlimited
pending signals (-i) 48192
max locked memory (kbytes, -l) 64
max memory size (kbytes, -m) unlimited
open files (-n) 1024
pipe size(512 bytes, -p) 8
POSIX message queues (bytes, -q) 819200
real-time priority (-r) 0
stack size (kbytes, -s) 8192
cpu time (seconds, -t) unlimited
max user processes (-u) 48192
virtual memory (kbytes, -v) unlimited
file locks (-x) unlimited
root@pinelp3:~# ps aux | wc -l ->While the service is
running
1084
root@pinelp3:~# ps aux | wc -l "
1084
root@pinelp3:~# ps aux | wc -l "
1084
root@pinelp3:~# ps aux | wc -l "
1084
root@pinelp3:~# ps aux | wc -l-->While the service is not
running.
572
root@pinelp3:~# free -m --> While service is running
totalusedfree shared buff/cache
available
Mem: 12117 628 459 22 11029
