| Posted | Nick | Remark | |
|---|---|---|---|
| #openstack-nova - 2020-01-09 | |||
| 12:40:57 | alex_xu | sean-k-mooney: both them are reconcile by rt.update_available_resource? | |
| 12:41:06 | sean-k-mooney | for the sriov migrating we move the dest pci deives that are claiimed too allocated and then go to in use in post live migration or get freed if we fail | |
| 12:41:46 | sean-k-mooney | the pci magnager work a littel differently | |
| 12:41:59 | alex_xu | and pci manager persistent the claim | |
| 12:42:05 | sean-k-mooney | yes | |
| 12:42:28 | alex_xu | vpmem need persistent also | |
| 12:42:45 | sean-k-mooney | well it persist it in that in the pci_stats? table we change the state of the device and recorred it as allocated fot the specic instnace | |
| 12:42:48 | alex_xu | and vpmem totally depends on instance.resources and instance.migration_context | |
| 12:43:23 | sean-k-mooney | ya. for vpmem at the moment i guess you have no other choice | |
| 12:43:27 | alex_xu | no vpmem claim persistent in instance.resources and instance.migration_context | |
| 12:43:35 | alex_xu | yea | |
| 12:44:00 | sean-k-mooney | i was hoping that wew woudl reconsile the different approches in sriov migraiton and numa migration by removing the live migration claim | |
| 12:44:54 | alex_xu | we still have RT at that time? | |
| 12:45:02 | alex_xu | I don't vision about that | |
| 12:45:13 | sean-k-mooney | and haneling numa without building on move claims but i guess i might have to do it the other way which make sme sad but | |
| 12:45:14 | alex_xu | s/don't vision/don't have vision' | |
| 12:45:39 | sean-k-mooney | i expect that we will always have the RT since plamcent does not handel assingment | |
| 12:46:07 | alex_xu | +1 | |
| 12:47:53 | sean-k-mooney | i just think the RT will do less work over time. | |
| 12:48:52 | alex_xu | yea, that i can imagine | |
| 12:49:39 | sean-k-mooney | it partly why i was hoping the move/rebiuld/noop/live-migration claim would eventury be removed | |
| 12:49:57 | sean-k-mooney | i was hoping we could simply what it does over time to not need them | |
| 12:51:27 | alex_xu | ok, i see | |
| 12:57:19 | sean-k-mooney | is the only place we store the vpmem allocation the in instance_extra table in the resouces filed | |
| 12:58:14 | sean-k-mooney | then in memeoy the resouce tracker discovers the avialabel vpmem namespaces and uses the instnace extra info to determin which ones are free and which are in use | |
| 13:01:01 | sean-k-mooney | ah yes we model this using the generic Resocue object and the specalised vpmemdevcie metaddata | |
| 13:01:07 | sean-k-mooney | ths is all coming back to me https://github.com/openstack/nova/blob/a4311c401b55c27321de7b282b242661af73fa34/nova/objects/resource.py#L39-L110 | |
| 13:03:34 | alex_xu | sean-k-mooney: yes | |
| 13:04:55 | sean-k-mooney | right so i rememebr we discussed if we need to do host side tracking like we do for pci device or if im memory + instastnce level tracking was enought like we do for vgpu | |
| 13:05:20 | sean-k-mooney | and we endup not doing host level tracking in the db | |
| 13:05:53 | alex_xu | yes | |
| 13:06:54 | sean-k-mooney | ya ok so the appoch in the spec makes sense then with that context. | |
| 13:07:00 | alex_xu | vgpu is more libvirt level tracking... | |
| 13:08:44 | sean-k-mooney | ya i was just looking at the vpmem discovery code https://github.com/openstack/nova/blob/master/nova/virt/libvirt/driver.py#L429-L514 | |
| 13:18:08 | huaqiang | 1;2C1;5C | |
| 13:20:46 | openstackgerrit | Lee Yarwood proposed openstack/nova stable/stein: libvirt: Add a rbd_connect_timeout configurable https://review.opendev.org/669167 | |
| 13:21:56 | openstackgerrit | Lee Yarwood proposed openstack/nova stable/stein: Skip cpu comparison on AArch64 https://review.opendev.org/699116 | |
| 13:50:02 | efried | Nova meeting in 10 minutes in #openstack-meeting | |
| 13:52:16 | efried | At a glance this morning it looked to me like nova-next is failing 100%. Has anyone looked at this? | |
| 13:52:35 | efried | ...before I dig in with my non-mriedem-ness? | |
| 13:53:42 | openstackgerrit | Matt Riedemann proposed openstack/nova master: Add a workaround config toggle to refuse ceph image upload https://review.opendev.org/657078 | |
| 14:00:22 | efried | Nova meeting now. | |
| 14:01:55 | efried | stephenfin, sean-k-mooney, bauzas: ^ | |
| 14:02:09 | efried | huaqiang: ^ | |
| 14:02:10 | efried | who else? | |
| 14:03:39 | brinzhang_ | :) | |
| 14:06:16 | brinzhang_ | Can I send my questions? :P | |
| 14:07:04 | alex_xu | brinzhang_: meeting is at #openstack-meeting channel | |
| 14:07:25 | brinzhang_ | alex_xu: yeah, joined | |
| 14:07:29 | efried | brinzhang_: yes, for sure. | |
| 14:07:59 | brinzhang_ | alex_xu, efried: thanks | |
| 14:29:01 | openstackgerrit | Merged openstack/nova master: functional: Make '_IntegratedTestBase' subclass 'InstanceHelperMixin' https://review.opendev.org/689182 | |
| 14:30:45 | bauzas | efried: sorry was on meeting | |
| 15:01:36 | sean-k-mooney | bauzas: every time you or somone else at redhat says they are sorry i was in a meeting i go crap did i miss one or was it a 1:1 :) | |
| 15:01:54 | bauzas | 1:1 indeed | |
| 15:02:09 | sean-k-mooney | although that is partly because im getting used to meeting again after the break | |
| 15:02:15 | brinzhang_ | hah | |
| 15:02:28 | efried | I don't like that personally because I think the mix of placement-ese and hw:-ese is more confusing than just hw:-ese | |
| 15:02:28 | efried | We could make that work, if we had to, because the hw:-ese part could impart enough information that you could infer the rest about your shared CPUs. | |
| 15:02:28 | efried | dansmith: Re specifying VCPUs in placement-ese and other stuff in hw:-ese... | |
| 15:02:58 | efried | point being: we're going to have to have snowflake syntax anyway, so might as well make it consistent. | |
| 15:03:36 | sean-k-mooney | efried: you coudld infer the amoung and then have a driver specifc convetion for how to select which ones would float and whcih woudl be pinned | |
| 15:03:44 | efried | Rather than asking people to understand which subset of placement-ese is side-effecty and which is not | |
| 15:03:45 | sean-k-mooney | but it make the code more complex | |
| 15:04:03 | efried | sean-k-mooney: Yes, exactly. Yes, exactly. | |
| 15:04:16 | efried | and also make it harder for the user to understand IMO. | |
| 15:05:36 | sean-k-mooney | if i was to code the algortiom it would be balance the shared cores evenly across numa nodes then make the rest pinned | |
| 15:05:40 | dansmith | I dunno, I'm just disappointed with the mess we've had, do have, and apparently will have | |
| 15:06:22 | sean-k-mooney | which in a singel numa node guest means all the shared cores are fist follow by the pinned cores | |
| 15:06:50 | dansmith | do the public clouds let you have this level of control over which cpus are pinned and to where? | |
| 15:06:54 | sean-k-mooney | and that is because the linux kernel and proably other has a prefernce for runing some code on core 0 of each numa node | |
| 15:07:38 | efried | sean-k-mooney: even allowing for future expansion where you can specify how many you want in each NUMA node, we could still do the math. My gripe is really about the UX. | |
| 15:08:14 | efried | dansmith: is that a leading question? | |
| 15:08:46 | sean-k-mooney | well today the just expose flaver with either pinning on or off or numa nodes. but you can configure this via the image too | |
| 15:08:52 | dansmith | efried: it's an honest one.. we used to have a shared value of "abstraction means not getting to turn every knob" | |
| 15:09:08 | efried | Isn't "our competitor can't do X, and neither can we, so let's make X possible so we're better than our competitor" how progress is made? | |
| 15:09:35 | efried | dansmith: and that abstraction still exists. You can still put up a flavor with no extra specs and get a VM. We're not taking away that simplicity. | |
| 15:09:57 | dansmith | efried: the same argument goes fo "some vendor shows up with a P2V'd ancient appliance that requires a specific hardware topology and we spent years trying to implement that instead of actually competing on something that matters" | |
| 15:10:04 | sean-k-mooney | so as an operate i can create a flavor with 8 cores and pinnnge and then as a user i can upload an image the says make the vm have 1 socket and, 2 thread per core, and 1 nuam node please | |
| 15:10:25 | efried | dansmith: I dig. But NUMA isn't going away. | |
| 15:10:52 | efried | and edge tuning is like the big thing, isn't it? | |
| 15:11:01 | dansmith | efried: no, numa isn't, that's not the point.. whether or not we need to provide this level of control over what the topology looks like instead of just providing a sane one with the asks we were given is. | |
| 15:11:26 | dansmith | efried: mostly because of legacy appliances afaik :) | |
| 15:11:32 | efried | if a good-enough VM was good enough, sure. | |
| 15:12:01 | efried | but in edge IIUC you need to be able to squeeze every cycle out of your hardware, no? | |
| 15:12:15 | sean-k-mooney | well if we were to provide a sane topology by default we would have to change our curren policy of 1 cpu socket per vcpu | |
| 15:12:25 | sean-k-mooney | but i get what you mean | |
| 15:12:27 | dansmith | that's not generally the reason they need to strictly control the topology.. it seems like the reason, but it's often not :) | |
| 15:12:33 | sean-k-mooney | sane default would be nice | |
| 15:12:48 | efried | I think we have sane defaults, don't we? | |
| 15:12:49 | dansmith | anyway, I'm not trying to stop the train on those grounds, | |
| 15:13:10 | sean-k-mooney | efried: i would not call the cpu toplogy nova generates sane | |
| 15:13:15 | efried | heh | |
| 15:13:22 | efried | well, it could be | |
| 15:13:34 | dansmith | I'm more looking for a signpost in the distance of what level of abstraction others have chosen | |
| 15:13:41 | sean-k-mooney | if you have a 16 VCPU guest it will give you a guest with 16 cpu socket each wtih a 1 core 1 thread cpu | |
| 15:14:11 | sean-k-mooney | and for software licence that chages per socket that is expensive | |
| 15:14:27 | sean-k-mooney | that iw why the cpu topology extra specs where added | |
| 15:14:35 | dansmith | exactly :) | |
| 15:14:40 | dansmith | not for perf tuning :) | |