Bug 590923 - /sbin/mkdumprd spins forever doing "readlink"
/sbin/mkdumprd spins forever doing "readlink"
Product: Fedora
Classification: Fedora
Component: kexec-tools (Show other bugs)
All Linux
low Severity medium
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Assigned To: Neil Horman
Fedora Extras Quality Assurance
Depends On:
  Show dependency treegraph
Reported: 2010-05-10 20:12 EDT by Roland McGrath
Modified: 2010-05-13 15:26 EDT (History)
1 user (show)

See Also:
Fixed In Version: kexec-tools-2.0.0-35.fc13
Doc Type: Bug Fix
Doc Text:
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Clone Of:
Last Closed: 2010-05-13 15:26:32 EDT
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RHEL 7.3 requirements from Atomic Host:
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Attachments (Terms of Use)
-x log (11.58 KB, text/plain)
2010-05-11 12:24 EDT, Roland McGrath
no flags Details
patch to fix how we sift through sysfs (725 bytes, patch)
2010-05-12 11:40 EDT, Neil Horman
no flags Details | Diff
updated patch (865 bytes, patch)
2010-05-12 14:46 EDT, Neil Horman
no flags Details | Diff

  None (edit)
Description Roland McGrath 2010-05-10 20:12:28 EDT
Description of problem:

First noticed during boot with kexec-tools installed,
also happens with manual "service kexec-tools start".
It spins forever chewing CPU.
I found that running /sbin/mkdumprd is where it happens and doing this by hand hits it too.

I've attached the log of running "bash -x /sbin/mkdumprd ..." where it eventually runs "readlink /sys/class/block/sda5" repeatedly forever.

Version-Release number of selected component (if applicable):

How reproducible:

Steps to Reproduce:
Actual results:

Expected results:

Additional info:
Comment 1 Neil Horman 2010-05-11 07:10:33 EDT
could you attach that file please?  thanks !
Comment 2 Roland McGrath 2010-05-11 12:24:25 EDT
Created attachment 413187 [details]
-x log

Oops, thought I'd attached it in the initial report.
Comment 3 Neil Horman 2010-05-12 11:40:26 EDT
Created attachment 413462 [details]
patch to fix how we sift through sysfs

looks like I forgot to port a RHEL patch over to Fedora.  Let me know if this fixes your problem.  Thanks!
Comment 4 Roland McGrath 2010-05-12 14:11:39 EDT
With that, the infinite loop is instead:

++ readlink ./device
Comment 5 Neil Horman 2010-05-12 14:46:55 EDT
Created attachment 413521 [details]
updated patch

sorry, missed a hunk from the backport.
Comment 6 Roland McGrath 2010-05-12 15:26:33 EDT
That fixes mkdumprd I guess.  It completed.  But "service kdump start" is not happy.  It just says "FAILED" with no details.  syslog gets:

May 12 12:25:46 magilla kdump: No crashkernel parameter specified for running kernel
May 12 12:25:46 magilla kdump: failed to start up
Comment 7 Neil Horman 2010-05-12 15:28:32 EDT
It told you exactly what the problem was:

"No crashkernel parameter specified for running

you need to specify a crashkernel command line parameter on the kernel command line.  For x86 system crashkernel=128M is usually sufficient.

I'll commit this change shortly.  Thanks!
Comment 8 Roland McGrath 2010-05-12 15:37:47 EDT
I'm using what you get out of the box for booting F-13 with kexec-tools installed.  I don't want to fiddle kernel parameters by hand.  Either it should just work, or it should not be chkconfig on by default.
Comment 9 Fedora Update System 2010-05-12 16:10:54 EDT
kexec-tools-2.0.0-35.fc13 has been submitted as an update for Fedora 13.
Comment 10 Fedora Update System 2010-05-13 15:26:27 EDT
kexec-tools-2.0.0-35.fc13 has been pushed to the Fedora 13 stable repository.  If problems still persist, please make note of it in this bug report.

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