https://oscourse.win

Very clever! We often call read/rcv system call to read requests from a connection, this copies data from kernel receive buffer to user space which has a cost.

This new patch changes this to allow zero copy with notification.

“Reading' data out of a socket instead becomes a “notification” mechanism, where the kernel tells userspace where the data is.”

This kernel patch enables zero copy from the receive queue.

https://lore.kernel.org/io-uring/ZwW7_cRr_UpbEC-X@LQ3V64L9R2/T/

0:00 Intro

1:30 patch summary

7:00 Normal Connection Read (Kernel Copy)

12:40 Zero copy Read

15:30 Performance