Xavier A CPU cores 4 and 5 always idle

Autonomous Vehicles DRIVE AGX Xavier DRIVE AGX Xavier General
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Hardware Platform: DRIVE AGX Xavier™ Developer Kit
Software Version: DRIVE Software 10
Host Machine Version: native Ubuntu 18.04
SDK Manager Version: 1.0.1.5538

I haven’t been able to schedule any tasks on Xavier A CPU cores 4 and 5 (numbering 1-6). No matter the usage of other CPU cores , those cores stay idle. Screenshot of htop attached. Xavier B appears to be using all 6 cores just fine.

When I use taskset on Xavier A, the default CPU masks exclude CPU cores 4 and 5 (taskset numbers them 3-4). I can’t even schedule tasks on cores 4 or 5 – if I try, taskset returns an error.

I’ve done a lot of searching around the forums but haven’t found anything specific to my issue. No calls to isolcpus anywhere that I can find, nothing that would explain this.

My application requires full performance from both Xavier SOCs. Does anyone have insight into this problem? Thanks.

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Dear @evanmt03s,
Could you check Only 4 cores out of 6 are available on Pegasus to see if it helps

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Thanks for your suggestion, I missed this thread. I bet this is the problem.

I’ll post again once I have a chance to try this out.

I’d like to say that if this is the case, this behavior – a process modifying cgroups after boot and taking up 2 of the 6 CPU cores by default, whether the user launches it or not – is pretty surprising to me.

I’d like to request that this behavior be better documented (if not changed) in a (near) future DRIVE OS version, for the benefit of the user community at large. I hope the responsible team(s) can take this request into consideration. Thanks!

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Dear @evanmt03s.
Thank you for suggestion. We will escalate this to documentation team.

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Hi @SivaRamaKrishnaNV, thanks. I appreciate that.

The fix proposed in that thread worked.