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#openstack-cyborg - 2020-06-02
06:27:10 Sundar brinzhang: on a resize, does Nova scheduler get involved? If so, can it pick a different host?
06:27:37 brinzhang Sundar, resize may need to change host,that not easy to control, I know it should support, but it need time
06:27:43 xinranwang I think it will do re-schedule
06:27:45 Sundar Libvirt does not support it for the default config: looks like you have to specify a different cpu model q35.
06:29:20 Sundar brinzhang: we already have the scheduler flow for device profiles and ARQs. Why do you think it is difficult?
06:30:59 Yumeng brinzhang: I think unshelve will also do re-schedule, right?
06:31:48 brinzhang unshelve jsut need to re-create ARQs, it's easy to get
06:32:38 brinzhang I am not search into resize, so I can not answer clearly.
06:32:48 Sundar We can bring this up in the Nova discussion.
06:33:35 Sundar Anyway, we need to tlak to them about other VM ops for accelerators.
06:33:39 Sundar *talk
06:33:42 shaohe_feng Sundar: a question about schedule. You have bring up a discussion about this:
06:33:52 brinzhang This release we have rebuild/evcaute, suspend/resume, shelve/unshelve, I think it's enough to do in V
06:34:03 shaohe_feng add a new filter for dynamic program
06:34:23 shaohe_feng let cyborg do the filter, right?
06:34:41 Sundar shaohe_feng: not sue what you are referring to
06:34:50 brinzhang In https://review.opendev.org/#/c/729945/5/api-guide/source/accelerator-support.rst we record the operations supported in cyborg
06:36:07 Yumeng brinzhang: I think we can also start to support resize, chenke can investigate in. anyway, we can start discuss with nova during the session.
06:36:28 brinzhang agree
06:37:53 brinzhang after chenke talked with nova team, I think we can get more info about resize.
06:38:19 shaohe_feng such as, currently the function of the FPGA is ovs with 4 VF, but no VM uses it. and now on more FPGA available , we can select this one ovs PFGA as IPsec with 2 NICs, and change its function.
06:38:52 shaohe_feng ^ Sundar so this need a scheduler improvement, right?
06:39:05 shaohe_feng and you bring up to add a new filter.
06:39:13 shaohe_feng I remember.
06:40:49 Sundar shaohe_feng: That doesn;t involve the Nova scheduler. We can define a device profile with a trait that selects that type of FPGA, and an accel:bitstream that refers to ipsec. Then Placement may return some FPGA with ovs image if it is free. But Cyborg will notice it does not have ipsec and do the programming.
06:41:36 Sundar What we don't have is this:
06:42:05 shaohe_feng yes, that's the current flow in cyborg at present
06:42:13 Sundar Say, we have two free FPGAs, one with ovs and with ipsec. In this case, we want the scheduler to pick the one with ipsec preferentially. That is not there today.
06:43:05 Sundar The scheduler has a weigher but it selects among hosts, not among allocation candidates from Placement
06:43:13 shaohe_feng you can not fill ovs or ipsec in the trait
06:43:44 Yumeng brinzhang: I was curious, given "unshelve jsut need to re-create ARQs, it's easy to get", does that mean shelve operation does not actually release the accelerator in hypervisor, the accelerator is still a claimed allocation, that's why there is no re-scheduler in unshelve.
06:44:00 Yumeng please correct me if I was wrong
06:44:00 shaohe_feng but the weigher also not support for FPGA, right?
06:44:08 Sundar That is right. At least, if you do, it makes it too specific -- if you ask for ipsec and no FPGA with ipsec is free, the request will fail. No reprogramming.
06:44:17 Sundar What we really want is preferred traits:
06:44:36 Sundar We should be able to say I prefer the resource provider have this trait but, if not, give me something
06:44:42 Sundar Alex Xu knows about this
06:45:00 shaohe_feng everyone also know about it
06:45:07 shaohe_feng -_-
06:45:19 shaohe_feng but we want to improve it
06:45:46 Sundar shaohe_feng: There are many weighers, and we cna write custom weighers too. None of them cover FPGA, because they deal with hosts, not device RPs.
06:45:57 shaohe_feng and everyone know placement is so weak :')
06:46:14 shaohe_feng we can consider how to improve it.
06:46:37 Sundar What I meant is, Alex Xu knows Cyborg wants preferred traits. I think he was looking into implementing it at some point, but he got busy with other things
06:47:00 shaohe_feng yes, we can consider write a custom weigher for FPGA
06:47:25 Sundar Nope, that won;t help, as I said
06:47:39 shaohe_feng he did not give us a good suggestion
06:47:54 shaohe_feng what he know, others also know \
06:48:01 shaohe_feng we want a good solution
06:48:13 shaohe_feng not the common knowledge
06:48:33 brinzhang Yumeng: when shelve instance we delete the instance's ARQs from nova and cyborg, when unshelve we should create it, it need to re-scheduler in unshelve
06:49:16 shaohe_feng yes, we can improve placement, every one can improve it. but we can let upstream accept it.
06:49:31 brinzhang Yumeng: the poc code is here, you can review https://review.opendev.org/#/c/729563/2
06:50:42 shaohe_feng such as SDL can used for placement, but it is a big change for placement, right? vendor can improve it in this way. but it is difficult in upstream, right?
06:51:12 Sundar If we can get preferred traits, that would help. Shall we add that to Nova discussion?
06:51:19 brinzhang we will introduce the service version to support these operations, controled in https://review.opendev.org/#/c/715326/13/nova/compute/api.py@288
06:52:23 shaohe_feng preferred is just a case of SDL. SDL can cover it.
06:54:18 shaohe_feng and preferred can not resolve the complex scenarios :')
06:54:24 Sundar Yumeng: ^
06:54:38 Sundar brinzhang: ^
06:55:15 Yumeng Sundar,yes sure. I will add operations to Nova etherpad
06:55:32 Sundar No I mean discuss preferred traits
06:55:32 shaohe_feng Yumeng no, not this release.
06:55:46 shaohe_feng the next release.
06:56:00 shaohe_feng I just want to know some history from sunder
06:56:04 Yumeng I don't think we have enough time to discuss preferred traits.
06:56:09 shaohe_feng but not preferred history
06:56:10 Yumeng yes next release.
06:56:12 brinzhang I found nova PTG time is too later for china, I will atten it asap,
06:56:32 shaohe_feng about the filter and weigher discussion
06:56:36 Yumeng this release, we discuss nova operations and smartnic integration
06:56:40 brinzhang Yumeng: you can ping me when this will be start
06:57:46 Yumeng yes, nova session is 10:00-11:00pm beijing time Friday.
06:57:53 Yumeng brinzhang:ok.
06:58:07 brinzhang Yumeng: ack
06:58:33 Sundar Ok, anything else for me? :)
06:59:00 Yumeng Nope for today. Thank you Sundar !
06:59:30 brinzhang Sundar, hope you have a good day, bye
06:59:30 Sundar Thank you, Yumeng and all! Have a good day.
06:59:32 Yumeng Have a good night. BTW, wil you come tomorrow?
06:59:49 Sundar Yumeng, am I required for some topic tomorrow?
07:00:20 Sundar New drivers and drive rprograms -- sounds interesting
07:00:33 Yumeng Driver program API support? API attribute?
07:00:42 Sundar I'll try to join for 1 hour, but I have a long day tomorrow
07:01:13 Sundar Bye for now :)
07:01:15 Yumeng ok. Thanks! Then I will move New drivers and drive rprograms first, others later.
07:01:27 Yumeng Sundar: bye.
07:02:27 brinzhang In zoom all chinese people?
07:02:51 Yumeng hi. let's take a break for 10 mins.
07:03:21 Yumeng brinzhang: nope. We have shogo and one guest.
07:03:45 Yumeng after ten mins shall we go back to zoom?
07:03:56 chenke are your phone ok with zoom? brin
07:03:56 Mudit Hello! from India this is Mudit
07:04:05 chenke hello dudit
07:04:11 chenke hello mudit
07:04:19 brinzhang Yeah, I asked but noone responed, I think my net is not very good
07:04:33 Yumeng hello Mudit! very welcome!
07:04:38 brinzhang welcome Mudit^
07:04:41 chenke you can ask again, if i here, i will reply you.
07:05:09 s_shogo Sure, I can't understand Mandarin,,,, thanks.

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