Messages in this thread | | | From | David Laight <> | Subject | RE: Feedback on 4.9 performance after PTI fixes | Date | Mon, 8 Jan 2018 17:26:06 +0000 |
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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
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