8 Jan
2018
8 Jan
'18
5:26 p.m.
From: Willy Tarreau
Sent: 07 January 2018 10:19
...
The impact inside VMs is quite big but it's not where we usuall install processes sensitive to syscall performance. I could find an even higher impact on a packet generation program dropping from 2.5 Mpps to 600kpps in the VM after the fix, but it doesn't make much sense to do this in VMs so I don't really care.
Why not? It will be related to the cost of sending (and probably receiving) network traffic in a VM. This is something that is done a lot.
Maybe not packet generation, but a UDP/IP benchmark inside a VM would be sensible. It may well be that moderate ethernet packet rates cause a massive performance drop when the host kernel has PTI enabled.
David