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Bug 1293230 - rt: netpoll: live lock with NAPI polling and busy polling on realtime kernel
Summary: rt: netpoll: live lock with NAPI polling and busy polling on realtime kernel
Keywords:
Status: CLOSED ERRATA
Alias: None
Product: Red Hat Enterprise Linux 7
Classification: Red Hat
Component: kernel-rt
Version: 7.3
Hardware: x86_64
OS: Linux
high
high
Target Milestone: rc
: ---
Assignee: Luis Claudio R. Goncalves
QA Contact: Zhenjie Chen
URL:
Whiteboard:
Depends On: 1292902
Blocks: 1295884
TreeView+ depends on / blocked
 
Reported: 2015-12-21 07:06 UTC by Jan Kurik
Modified: 2016-08-15 22:54 UTC (History)
7 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Cause: As the realtime kernel replaces most of the spinlocks by rtmutexes, in order to maximize the preemption points inside the kernel, the locking scheme used in both NAPI polling and busy polling could become out of synchronization with the State Machine they protected. That could be observed when a machine with faster NICs (10g or 40g) was subject to a heavy pressure receiving network packets. Consequence: The system could experience a livelock that would either slowly degrade the system performance up to a halt or disable the network adapter and halt. Fix: the locking schemes on NAPI polling and busy polling routines were hardened to enforce the State machine sanity. Result: the system works fine under pressure.
Clone Of: 1292902
: 1295884 (view as bug list)
Environment:
Last Closed: 2016-02-16 10:50:02 UTC
Target Upstream Version:
Embargoed:

Attachments (Terms of Use)
netpoll: Always take poll_lock when doing polling (2.17 KB, patch)
2016-01-07 03:55 UTC, Luis Claudio R. Goncalves 		no flags Details | Diff
Revert "ixgbevf: Prevent livelock spinning grabbing ixgbevf_qv_lock" (3.18 KB, patch)
2016-01-07 03:57 UTC, Luis Claudio R. Goncalves 		no flags Details | Diff
revert "ixgbe: Prevent livelock spinning grabbing ixgbe_qv_lock" (3.53 KB, patch)
2016-01-07 03:58 UTC, Luis Claudio R. Goncalves 		no flags Details | Diff
revert "sfc: Prevent livelock spinning grabbing efx_channel_lock" (3.07 KB, patch)
2016-01-07 03:58 UTC, Luis Claudio R. Goncalves 		no flags Details | Diff
Setup notes for hp-dl388g8-09.rhts.eng.nay.redhat.com (2.05 KB, text/plain)
2016-02-02 14:20 UTC, Clark Williams 		no flags Details
Setup notes for rhelrt-17.farm.hsv.redhat.com (2.11 KB, text/plain)
2016-02-02 14:21 UTC, Clark Williams 		no flags Details
View All


Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2016:0212 0 normal SHIPPED_LIVE Important: kernel-rt security, bug fix, and enhancement update 2016-02-16 15:46:40 UTC

Description Jan Kurik 2015-12-21 07:06:59 UTC 
This bug has been copied from bug #1292902 and has been proposed
to be backported to 7.2 z-stream (EUS).
Comment 3 Luis Claudio R. Goncalves 2016-01-07 03:55:55 UTC 
Created attachment 1112330 [details]
netpoll: Always take poll_lock when doing polling
Comment 4 Luis Claudio R. Goncalves 2016-01-07 03:57:04 UTC 
Created attachment 1112331 [details]
Revert "ixgbevf: Prevent livelock spinning grabbing ixgbevf_qv_lock"
Comment 5 Luis Claudio R. Goncalves 2016-01-07 03:58:09 UTC 
Created attachment 1112332 [details]
revert "ixgbe: Prevent livelock spinning grabbing ixgbe_qv_lock"
Comment 6 Luis Claudio R. Goncalves 2016-01-07 03:58:51 UTC 
Created attachment 1112333 [details]
revert "sfc: Prevent livelock spinning grabbing efx_channel_lock"
Comment 11 Clark Williams 2016-02-02 14:20:06 UTC 
Created attachment 1120448 [details]
Setup notes for hp-dl388g8-09.rhts.eng.nay.redhat.com

Notes for reproducing this bug on an HP DL388 with SolarFlare (sfc) NIC
Comment 12 Clark Williams 2016-02-02 14:21:32 UTC 
Created attachment 1120449 [details]
Setup notes for rhelrt-17.farm.hsv.redhat.com

setup notes for test box in HSV lab
Comment 16 errata-xmlrpc 2016-02-16 10:50:02 UTC 
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://rhn.redhat.com/errata/RHSA-2016-0212.html
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