Re: [LSF/MM TOPIC] NVMe Performance: Userspace vs Kernel

[Bart Van Assche <bvanassche@acm.org>]

On Fri, 2019-02-15 at 21:19 +0000, Felipe Franciosi wrote:
> Hi All,
> 
> I'd like to attend LSF/MM this year and discuss the kernel performance when accessing NVMe devices, specifically (but not limited to) Intel Optane Memory (which boasts very low latency and high
> iops/throughput per NVMe controller).
> 
> Over the last year or two, I have done extensive experimentation comparing applications using libaio to those using SDPK. For hypervisors, where storage devices can be exclusively accessed with
> userspace drivers (given the device can be dedicated to a single process), using SPDK has proven to be significantly faster and more efficient. That remains true even in the latest versions of the
> kernel.
> 
> I have presented work focusing on hypervisors in several conferences during this time. Although I appreciate the LSF/MM is more discussion-oriented, I am linking a couple of these presentations for
> reference:
> 
> Flash Memory Summit 2018
> https://www.flashmemorysummit.com/English/Collaterals/Proceedings/2018/20180808_SOFT-202-1_Franciosi.pdf
> 
> Linux Piter 2018
> https://linuxpiter.com/system/attachments/files/000/001/558/original/20181103_-_AHV_and_SPDK.pdf
> 
> For LSF/MM, instead of focusing on hypervisors, I would like to discuss what can be done to achieve better efficiency and performance when using the kernel. My data include detailed results
> considering various scenarios like different NUMA configurations, IRQ affinity and polling modes.

Hi Felipe,

It seems like you missed the performance comparison between SPDK and io_uring
Jens posted recently?

Bart.