Re: [PATCH] make blk_mq_map_queues more friendly for cpu topology

[Dongli Zhang]

On 03/27/2019 05:17 PM, luferry wrote:
> 
> 
> 
> Actually,  I just bought one vm from public cloud provider and run into this problem.
> after reading code and compare pci device info, I reproduce this scenario.

There is lack of vector issue when number of queues is more than maxcpus as well.

https://lore.kernel.org/lkml/e4afe4c5-0262-4500-aeec-60f30734b4fc@default

I was going to send out patch to fix that specific case on virtio side.

BTW, is your VM's virtio mmio based or pci based?

As mentioned in previous email, when I was playing with firecracker by amazon,
the virtio-blk is mmio based. Not sure if that would lead to the lack of vector
issue.

Dongli Zhang