Using MemorySwapMax in systemd with Ubuntu 18.04

tuk

11/2/22, 3:30 PM

I am trying to restrict the swap usage of a process using MemorySwapMax as mentioned in the doc with Ubuntu 18.04.

Environment

ubuntu@vrni-platform:/usr/lib/systemd/system$ uname -a
Linux vrni-platform 4.15.0-143-generic #147-Ubuntu SMP Wed Apr 14 16:10:11 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux

ubuntu@vrni-platform:/usr/lib/systemd/system$ systemctl --version
systemd 237
+PAM +AUDIT +SELINUX +IMA +APPARMOR +SMACK +SYSVINIT +UTMP +LIBCRYPTSETUP +GCRYPT +GNUTLS +ACL +XZ +LZ4 +SECCOMP +BLKID +ELFUTILS +KMOD -IDN2 +IDN -PCRE2 default-hierarchy=hybrid

My systemd unit file looks like below

[Unit]
Description=My service
After=network.target
StartLimitIntervalSec=0
[Service]
Type=simple
Restart=always
RestartSec=1
User=support
MemoryMax=2000M
KillMode=process
MemoryAccounting=true
OOMScoreAdjust=1000
MemorySwapMax=0
ExecStart=/usr/bin/java -cp /home/support -XX:NativeMemoryTracking=summary -Xmx10000m MemoryConsumer 100 200 1

I tried to disable swap for this process by specifying 0 for MemorySwapMax. But it seems there was some issue in systemd which is fixed in systemd 239.

So I also tried setting MemorySwapMax=1M. But that also seems to be not restricting the swap memory usage for this systemd service.

The documentation for MemorySwapMax states this

This setting is supported only if the unified control group hierarchy is used and disables MemoryLimit=.

Can someone let me know how can I know if unified control group hierarchy is being used in my setup or what else could be the problem which is not allowing MemorySwapMax to take effect?

0 + 0

swap

systemd

18.04

Elon Musk

I sit in a Tesla and translated this thread with Ai:

EN: Using MemorySwapMax in systemd with Ubuntu 18.04

TH: การใช้ MemorySwapMax ใน systemd กับ Ubuntu 18.04

RO: Utilizarea MemorySwapMax în systemd cu Ubuntu 18.04

RU: Использование MemorySwapMax в systemd с Ubuntu 18.04

VI: Sử dụng MemorySwapMax trong systemd với Ubuntu 18.04

Post an answer

Most people don’t grasp that asking a lot of questions unlocks learning and improves interpersonal bonding. In Alison’s studies, for example, though people could accurately recall how many questions had been asked in their conversations, they didn’t intuit the link between questions and liking. Across four studies, in which participants were engaged in conversations themselves or read transcripts of others’ conversations, people tended not to realize that question asking would influence—or had influenced—the level of amity between the conversationalists.