Bug 608641
Summary: | vegas and veno possible division by zero bug | ||||||
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Product: | Red Hat Enterprise Linux 5 | Reporter: | Veaceslav Falico <vfalico> | ||||
Component: | kernel | Assignee: | Neil Horman <nhorman> | ||||
Status: | CLOSED ERRATA | QA Contact: | Eryu Guan <eguan> | ||||
Severity: | high | Docs Contact: | |||||
Priority: | urgent | ||||||
Version: | 5.3 | CC: | eguan, nhorman, peterm, rbinkhor, tao | ||||
Target Milestone: | rc | ||||||
Target Release: | --- | ||||||
Hardware: | All | ||||||
OS: | Linux | ||||||
Whiteboard: | |||||||
Fixed In Version: | Doc Type: | Bug Fix | |||||
Doc Text: | Story Points: | --- | |||||
Clone Of: | Environment: | ||||||
Last Closed: | 2011-01-13 21:39:46 UTC | Type: | --- | ||||
Regression: | --- | Mount Type: | --- | ||||
Documentation: | --- | CRM: | |||||
Verified Versions: | Category: | --- | |||||
oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |||||
Cloudforms Team: | --- | Target Upstream Version: | |||||
Embargoed: | |||||||
Attachments: |
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Description
Veaceslav Falico
2010-06-28 11:21:09 UTC
Hello, The customer confirmed that with the if (vrtt == 0) vrtt = 1; patch in tcp_vegas_rtt_calc() the problem does not occur. Is there anything else I can do? Thank you! Created attachment 437620 [details]
proposed patch
Hello,
The upstream is quite heavily modified (and the logic of the caller of tcp_vegas_rtt_calc also), so that I've tried to take only the parts that affect us and our bug. In the upstream if we see that the time diff of rtt is <=0, we just return without any warnings, considering it to be just a bogus value.
Please review and say if testing is needed.
Thank you!
This request was evaluated by Red Hat Product Management for inclusion in a Red Hat Enterprise Linux maintenance release. Product Management has requested further review of this request by Red Hat Engineering, for potential inclusion in a Red Hat Enterprise Linux Update release for currently deployed products. This request is not yet committed for inclusion in an Update release. in kernel-2.6.18-214.el5 You can download this test kernel from http://people.redhat.com/jwilson/el5 Detailed testing feedback is always welcomed. Following steps in comment 9, got panic on -194 kernel Code: f7 75 10 8d 14 09 8b 8b d4 04 00 00 29 c2 3b 8b d0 04 00 00 RIP [<ffffffff8855419d>] :tcp_vegas:tcp_vegas_cong_avoid+0x82/0x14d RSP <ffff810001757b00> hit <0>Kernel panic - not syncing: Fatal exception Code: 66 83 7f 02 02 77 18 55 89 d8 51 8b 4c 24 08 8b 54 24 0c e8 6b 6f b9 c7 59 5b e9 c1 00 00 00 8d 0c 36 31 d2 0f af 77 08 8d 04 36 <f7> 77 04 29 c1 89 4f 10 8b 93 6c 03 00 00 3b 93 68 03 00 00 77 EIP: [<f8a5e148>] tcp_veno_cong_avoid+0xac/0x16f [tcp_veno] SS:ESP 0068:c074adcc <0>Kernel panic - not syncing: Fatal exception in interrupt Confirmed there was no panic on -230 kernel. An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on therefore solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHSA-2011-0017.html |