[dpdk-dev] Having troubles binding an SR-IOV VF to uio_pci_generic on Amazon instance

Avi Kivity avi at scylladb.com
Thu Oct 1 11:59:47 CEST 2015



On 10/01/2015 12:55 PM, Michael S. Tsirkin wrote:
> On Thu, Oct 01, 2015 at 12:22:46PM +0300, Avi Kivity wrote:
>> It's easy to claim that
>> a solution is around the corner, only no one was looking for it, but the
>> reality is that kernel bypass has been a solution for years for high
>> performance users,
> I never said that it's trivial.
>
> It's probably a lot of work. It's definitely more work than just abusing
> sysfs.
>
> But it looks like a write system call into an eventfd is about 1.5
> microseconds on my laptop. Even with a system call per packet, system
> call overhead is not what makes DPDK drivers outperform Linux ones.
>

1.5 us = 0.6 Mpps per core limit.  dpdk performance is in the tens of 
millions of packets per system.

It's not just the lack of system calls, of course, the architecture is 
completely different.



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