On Sat, Jul 30, 2022 at 4:00 AM Alexander Aring <aahringo@xxxxxxxxxx> wrote: > > Hi, > > On Fri, Jul 29, 2022 at 8:55 PM Steven Rostedt <rostedt@xxxxxxxxxxx> wrote: > > > > On Fri, 29 Jul 2022 17:48:08 -0400 > > Alexander Aring <aahringo@xxxxxxxxxx> wrote: > > > > > > > > > > Bah, I kept getting confused by when to use instance vs ctx->instance, > > > > and I guess I messed this one up. > > > > > > I tested it and it seems to fix the problem..., so if it's not to late: > > > > > > Tested-by: Alexander Aring <aahringo@xxxxxxxxxx> > > > > Not too late. I haven't downloaded the patch from patchwork yet (nor my > > other patches). > > > > > > > > I am not sure what I should expect from the PTP time synchronization > > > over IP capable interfaces (it never worked for me) but I need to say > > > it is significantly slower than kvm time synchronization with vsock > > > and I am using only virtual interfaces. On the agents I get a couple > > > of: > > > > Well, kvm time synchronization doesn't do much between the host and > > guest. And I'm looking at making it do even less. That's because the > > kvm synchronization is just "read the offset and shift of the guest > > from the host and do the calculations via the reader (trace-cmd > > report or kernelshark)". But the P2P is sending packets back and forth > > between the host and guest and trying to figure out the round trip > > latency. > > > > okay. To be more specific it took about ~20 minutes until I saw the > "Press Ctrl-C to stop recording..." message for 3 agents. Is that > normal? It doesn't seem normal, usually takes less than a minute when I tested with 2 agents (VMs running on the same host). PTP works by exchanging a lot of packets over the network between the host and the agent, so it depends on the network and on the guest. Currently the PTP logic works sequentially - one agent at a time. That could be optimized, the agents can be processed in parallel. But definitely 20 minutes for 3 agents (~7min per agent) is not normal. > > - Alex > -- Tzvetomir (Ceco) Stoyanov VMware Open Source Technology Center
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