Empty Promise: Zero-Copy Receive for vhost by Mike Rapoport

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In para-virtual networking with virtio-net/vhost, the copying of packet between the hypervisor and the guest is one of the major sources of the overhead, especially for the large packets. And, although, zero-copy transmit was merged into the Linux kernel a few years ago, the "receive side zero copy" item is still in the KVM NetworkingTodo, and probably will remain there for some more time.

Our attempted approach to implementation of zero-copy receive for virtio-net and vhost that leveraged receive-side steering abilities of the modern high speed network cards didn't improve anything and just moved the bottleneck to another place.

The talk presents what we've tried, why we thought there will be an improvement and what were the reasons for their absence .

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Mike Rapoport
Researcher
IBM

Mike has lots of programming experience in different areas ranging from medical equipment to visual simulation, but most of all he likes hacking on Linux kernel and low level stuff. Throughout his career Mike promoted use of free and open source software and made quite a few contributions to the Linux kernel. Now Mike works at IBM Research - Haifa focusing on containers and virtualization.

Видео Empty Promise: Zero-Copy Receive for vhost by Mike Rapoport канала KVM Forum