[Bug 2109303] Re: dhclient hang when tons of ip addresses exist
Dongdong Wang
2109303 at bugs.launchpad.net
Fri Apr 25 02:11:43 UTC 2025
** Description changed:
Ubuntu
- ==============
+ ======
No LSB modules are available.
Description: Ubuntu 24.04.2 LTS
Release: 24.04
Package
- ==============
+ =======
isc-dhcp-client:
- Installed: 4.4.3-P1-4ubuntu2
- Candidate: 4.4.3-P1-4ubuntu2
- Version table:
- *** 4.4.3-P1-4ubuntu2 500
- 500 http://archive.ubuntu.com/ubuntu noble/universe amd64 Packages
- 100 /var/lib/dpkg/status
-
+ Installed: 4.4.3-P1-4ubuntu2
+ Candidate: 4.4.3-P1-4ubuntu2
+ Version table:
+ *** 4.4.3-P1-4ubuntu2 500
+ 500 http://archive.ubuntu.com/ubuntu noble/universe amd64 Packages
+ 100 /var/lib/dpkg/status
Steps to Reproduce
==================
# ip l add dev dummy type dummy
# ip l set dev dummy up
# for i in {1..50}; do for j in {1..50}; do ip a a 192.168.$i.$j/24 dev dummy; done; done
# ip -o a show dev dummy | wc -l
2500
# dhclient -v dummy
Result
======
After the operations above, we can see the dhclient hanging. The top command showed the dhclient's memory
was increasing, seemed a memory leak happened.
-
top - 01:52:58 up 12 days, 23:38, 0 user, load average: 2.46, 2.44, 2.26
Tasks: 5 total, 1 running, 2 sleeping, 2 stopped, 0 zombie
%Cpu(s): 2.4 us, 1.4 sy, 0.0 ni, 96.1 id, 0.1 wa, 0.0 hi, 0.0 si, 0.0 st
MiB Mem : 772016.8 total, 614728.2 free, 111628.2 used, 50758.8 buff/cache
MiB Swap: 0.0 total, 0.0 free, 0.0 used. 660388.6 avail Mem
- PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
- 1 root 20 0 4.5m 3.8m 3.2m S 0.0 0.0 0:00.00 bash
- 10 root 20 0 4.6m 4.1m 3.4m S 0.0 0.0 0:00.59 bash
- 2869 root 20 0 3.2m 1.3m 1.2m T 0.0 0.0 0:00.00 dhclient
- 2870 root 20 0 188.7m 185.9m 2.3m T 0.0 0.0 2:09.55 dhclient
- 2879 root 20 0 8.7m 5.0m 2.9m R 0.0 0.0 0:00.00 top
+ PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
+ 1 root 20 0 4.5m 3.8m 3.2m S 0.0 0.0 0:00.00 bash
+ 10 root 20 0 4.6m 4.1m 3.4m S 0.0 0.0 0:00.59 bash
+ 2869 root 20 0 3.2m 1.3m 1.2m T 0.0 0.0 0:00.00 dhclient
+ 2870 root 20 0 188.7m 185.9m 2.3m T 0.0 0.0 2:09.55 dhclient
+ 2879 root 20 0 8.7m 5.0m 2.9m R 0.0 0.0 0:00.00 top
** Description changed:
Ubuntu
======
No LSB modules are available.
Description: Ubuntu 24.04.2 LTS
Release: 24.04
Package
=======
isc-dhcp-client:
Installed: 4.4.3-P1-4ubuntu2
Candidate: 4.4.3-P1-4ubuntu2
Version table:
*** 4.4.3-P1-4ubuntu2 500
500 http://archive.ubuntu.com/ubuntu noble/universe amd64 Packages
100 /var/lib/dpkg/status
Steps to Reproduce
==================
# ip l add dev dummy type dummy
# ip l set dev dummy up
# for i in {1..50}; do for j in {1..50}; do ip a a 192.168.$i.$j/24 dev dummy; done; done
# ip -o a show dev dummy | wc -l
2500
# dhclient -v dummy
Result
======
- After the operations above, we can see the dhclient hanging. The top command showed the dhclient's memory
- was increasing, seemed a memory leak happened.
+ After the operations above, we could see the dhclient hanging.
+ The top command showed the dhclient's memory was increasing,
+ seemed a memory leak happened. Also CPU usage was pretty high.
- top - 01:52:58 up 12 days, 23:38, 0 user, load average: 2.46, 2.44, 2.26
- Tasks: 5 total, 1 running, 2 sleeping, 2 stopped, 0 zombie
- %Cpu(s): 2.4 us, 1.4 sy, 0.0 ni, 96.1 id, 0.1 wa, 0.0 hi, 0.0 si, 0.0 st
- MiB Mem : 772016.8 total, 614728.2 free, 111628.2 used, 50758.8 buff/cache
- MiB Swap: 0.0 total, 0.0 free, 0.0 used. 660388.6 avail Mem
+ top - 02:13:48 up 12 days, 23:59, 0 user, load average: 2.99, 2.62, 2.43
+ Tasks: 5 total, 2 running, 3 sleeping, 0 stopped, 0 zombie
+ %Cpu(s): 1.8 us, 1.9 sy, 0.0 ni, 96.3 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st
+ MiB Mem : 772016.8 total, 614554.4 free, 111778.8 used, 50785.8 buff/cache
+ MiB Swap: 0.0 total, 0.0 free, 0.0 used. 660238.0 avail Mem
- PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
- 1 root 20 0 4.5m 3.8m 3.2m S 0.0 0.0 0:00.00 bash
- 10 root 20 0 4.6m 4.1m 3.4m S 0.0 0.0 0:00.59 bash
- 2869 root 20 0 3.2m 1.3m 1.2m T 0.0 0.0 0:00.00 dhclient
- 2870 root 20 0 188.7m 185.9m 2.3m T 0.0 0.0 2:09.55 dhclient
- 2879 root 20 0 8.7m 5.0m 2.9m R 0.0 0.0 0:00.00 top
+ PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
+ 2870 root 20 0 283.4m 282.3m 2.3m R 100.0 0.0 5:05.29 dhclient
+ 1 root 20 0 4.5m 3.8m 3.2m S 0.0 0.0 0:00.00 bash
+ 10 root 20 0 4.6m 4.1m 3.4m S 0.0 0.0 0:00.59 bash
+ 2869 root 20 0 3.2m 1.3m 1.2m S 0.0 0.0 0:00.00 dhclient
+ 2882 root 20 0 8.7m 5.0m 2.9m R 0.0 0.0 0:00.01 top
--
You received this bug notification because you are a member of Ubuntu
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https://bugs.launchpad.net/bugs/2109303
Title:
dhclient hang when tons of ip addresses exist
Status in isc-dhcp package in Ubuntu:
New
Bug description:
Ubuntu
======
No LSB modules are available.
Description: Ubuntu 24.04.2 LTS
Release: 24.04
Package
=======
isc-dhcp-client:
Installed: 4.4.3-P1-4ubuntu2
Candidate: 4.4.3-P1-4ubuntu2
Version table:
*** 4.4.3-P1-4ubuntu2 500
500 http://archive.ubuntu.com/ubuntu noble/universe amd64 Packages
100 /var/lib/dpkg/status
Steps to Reproduce
==================
# ip l add dev dummy type dummy
# ip l set dev dummy up
# for i in {1..50}; do for j in {1..50}; do ip a a 192.168.$i.$j/24 dev dummy; done; done
# ip -o a show dev dummy | wc -l
2500
# dhclient -v dummy
Result
======
After the operations above, we could see the dhclient hanging.
The top command showed the dhclient's memory was increasing,
seemed a memory leak happened. Also CPU usage was pretty high.
top - 02:13:48 up 12 days, 23:59, 0 user, load average: 2.99, 2.62, 2.43
Tasks: 5 total, 2 running, 3 sleeping, 0 stopped, 0 zombie
%Cpu(s): 1.8 us, 1.9 sy, 0.0 ni, 96.3 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st
MiB Mem : 772016.8 total, 614554.4 free, 111778.8 used, 50785.8 buff/cache
MiB Swap: 0.0 total, 0.0 free, 0.0 used. 660238.0 avail Mem
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
2870 root 20 0 283.4m 282.3m 2.3m R 100.0 0.0 5:05.29 dhclient
1 root 20 0 4.5m 3.8m 3.2m S 0.0 0.0 0:00.00 bash
10 root 20 0 4.6m 4.1m 3.4m S 0.0 0.0 0:00.59 bash
2869 root 20 0 3.2m 1.3m 1.2m S 0.0 0.0 0:00.00 dhclient
2882 root 20 0 8.7m 5.0m 2.9m R 0.0 0.0 0:00.01 top
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