Possible to increase KSM performance?

en4ble

Member
Feb 24, 2023
73
5
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It seems like KSM performance hit its ceiling at around 170GB (ksmd 100%).

1729867860122.png

I was wondering if there are any ways to increase that?

CPU usage is not a constrain since VMs are more memory intense and they share a lot with each other thus KSM benefit.

I appreciate in advance any suggestions on that matter. If I need to provide more artifacts please let me know.

Code:
/etc/ksmtuned.conf
# Configuration file for ksmtuned.

# How long ksmtuned should sleep between tuning adjustments
# KSM_MONITOR_INTERVAL=60

# Millisecond sleep between ksm scans for 16Gb server.
# Smaller servers sleep more, bigger sleep less.
# KSM_SLEEP_MSEC=100

# KSM_NPAGES_BOOST=300
# KSM_NPAGES_DECAY=-50
# KSM_NPAGES_MIN=64
# KSM_NPAGES_MAX=1250

# KSM_THRES_COEF=20
# KSM_THRES_CONST=2048

# uncomment the following if you want ksmtuned debug info

# LOGFILE=/var/log/ksmtuned
# DEBUG=1
 
I was wondering if there are any ways to increase that?
Sure: use more Ram ;--)

Well..., https://pve.proxmox.com/wiki/Dynamic_Memory_Management#KSM_in_action says: "...(using at least 80% of your physical memory on the host)..." and you are still under this level :)

----
Sidenote: my personal understanding is that I for myself will try really hard not to over-commit memory so much. 165 GB is a lot, even when you have a TiB. Obviously your mileage does vary, which is fine - as long as it works for you :-)
 
It seems like KSM performance hit its ceiling at around 170GB (ksmd 100%).

View attachment 76802

I was wondering if there are any ways to increase that?

CPU usage is not a constrain since VMs are more memory intense and they share a lot with each other thus KSM benefit.

I appreciate in advance any suggestions on that matter. If I need to provide more artifacts please let me know.

Try latest 6.8 kernel first