Bug 1088622
Summary: | Fedora 20 freezes; Fedora 19 runs correctly | ||||||||
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Product: | [Fedora] Fedora | Reporter: | David A. De Graaf <dad> | ||||||
Component: | kernel | Assignee: | Kernel Maintainer List <kernel-maint> | ||||||
Status: | CLOSED WORKSFORME | QA Contact: | Fedora Extras Quality Assurance <extras-qa> | ||||||
Severity: | high | Docs Contact: | |||||||
Priority: | unspecified | ||||||||
Version: | 20 | CC: | airlied, ajax, aquini, arozansk, atomlin, bskeggs, chrisw, davej, dwmw2, eparis, gansalmon, hdegoede, itamar, ivecera, jarodwilson, jforbes, jglisse, johannbg, jonathan, josef, j, jwboyer, kernel-maint, kmcmartin, linville, lnykryn, madhu.chinakonda, m.a.young, mchehab, mjg59, msekleta, nhorman, ohadlevy, plautrba, steved, systemd-maint, vpavlin, zbyszek | ||||||
Target Milestone: | --- | ||||||||
Target Release: | --- | ||||||||
Hardware: | i686 | ||||||||
OS: | Linux | ||||||||
Whiteboard: | |||||||||
Fixed In Version: | Doc Type: | Bug Fix | |||||||
Doc Text: | Story Points: | --- | |||||||
Clone Of: | Environment: | ||||||||
Last Closed: | 2014-06-30 16:58:27 UTC | Type: | Bug | ||||||
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
David A. De Graaf
2014-04-16 21:39:32 UTC
I cannot replicate this bug. After letting F19 run for about 6 days, I switched back to F20, intending to collect a pristine /var/log/messages and post it here after the expected freeze. It never happened. F20 has been running perfectly for several days. I don't know what changed, but I apologize for the noise, and withdraw this BZ. Sorry. I rescind my apology. :-) I can now produce a freeze reliably and present some actual data. If I induce the freeze *and* keep the attached crt monitor unblanked, 23 sec after the freeze occurs, the system spews error messages to the "console". Nothing meaningful ever goes to /var/log/messages or to the journal because, surprise, the system is frozen. I have photographed the "console" when it displays the first batch of messages and again after a few minutes to show that the soft lockup repeats every 23 seconds - forever, apparently. The significant first lines, transcribed from the photo, read: [ 500.055014] BUG: soft lockup - CPU#0 stuck for 23s! [rsync:2173] [ 500.055014] CPU: 0 PID: 2173 Comm: rsync Tainted: PF 0 3.13.9-200.fc20.i686+PAE #1 Apparently rsync interacts badly with the kernel because it is rsync, exclusively, that triggers the freeze. In this scenario I have allowed the machine to boot up in multiuser mode (init 3) but never started any graphical interface. The console still waits for me to login. On another machine I start 'gkrellm -s datbird &" just to see when the freeze occurs. Then on that other machine I start a backup script that relies on autofs, nfs, ssh, find, and rsync. All goes well until rsync starts to transfer files - then the freeze. If I don't run the rsync backup script the machine runs perfectly all day long. Unfortunately, it's role in life is to maintain a backup image of my main server, which gets updated at 11:30PM every night. Freezes are a unique feature of F20; if I reboot to F19 no freezes occur. I see a large number of other BZ's reporting a similar 23s soft lockup; most don't mention rsync. However, Bug 1081470 - soft lockup - CPU#1 stuck for 23s! [rsync:17305] does, and may be related. A Debian user reports similar behaviour as long ago as 2012-11-30: http://forums.debian.net/viewtopic.php?f=10&t=89166 Created attachment 890103 [details]
Console photo of first error messge
Created attachment 890104 [details]
Console photo of later error messages
Apparently this bug has been exterminated. Thanks to all. After finding that the freezing was 100% correlated with rsync running in a backup script, I redirected the backup to another machine. This stopped the freezing. Recently I restored the backup to the original configuration. No FREEZE! Sometime between then and now a kernel update seems to have fixed the problem. Good work! Thank you for letting us know. |