Bug 410 - KNI deadlocks when used with Mellanox device
Summary: KNI deadlocks when used with Mellanox device
Status: UNCONFIRMED
Alias: None
Product: DPDK
Classification: Unclassified
Component: other (show other bugs)
Version: 18.02
Hardware: All All
: Normal normal
Target Milestone: ---
Assignee: Ferruh YIGIT
URL:
Depends on:
Blocks:
 
Reported: 2020-02-26 00:52 CET by Stephen Hemminger
Modified: 2021-02-08 17:43 CET (History)
2 users (show)


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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.
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