Bug 410

Summary:	KNI deadlocks when used with Mellanox device
Product:	DPDK	Reporter:	Stephen Hemminger (stephen)
Component:	other	Assignee:	Ferruh YIGIT (ferruh.yigit)
Status:	UNCONFIRMED ---
Severity:	normal	CC:	ajit.khaparde, thomas
Priority:	Normal
Version:	18.02
Target Milestone:	---
Hardware:	All
OS:	All

Description Stephen Hemminger 2020-02-26 00:52:30 CET

The KNI driver calls out to userspace holding the kernel networking lock (RTNL).
This causes deadlock when a DPDK device driver (like Mellanox) needs to interact with the kernel to change the underlying device.

This is a design flaw in the original implementation of KNI, only exposed by the first bifurcated drivers.

See: https://patchwork.dpdk.org/patch/64106/

Comment 1 Ajit Khaparde 2020-02-26 19:14:40 CET

Ferruh, Assigning to you based on your response to the patch. Thanks

Comment 2 Thomas Monjalon 2021-02-08 14:26:02 CET

Stephen, what is the conclusion please?

Comment 3 Stephen Hemminger 2021-02-08 17:43:24 CET

Thomas this bug is still present. See the bugzilla entry for discussion.
There is no easy fix for this. It is a design flaw in KNI.