Bug 1147062

Summary: glibc's lock elison support causes apps to crash after Haswel microcode update
Product: [Fedora] Fedora Reporter: Hans de Goede <hdegoede>
Component: glibcAssignee: Carlos O'Donell <codonell>
Status: CLOSED DUPLICATE QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: unspecified Docs Contact:
Priority: unspecified    
Version: 21CC: codonell, fweimer, jakub, law, pfrankli, spoyarek
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Last Closed: 2014-09-26 18:35:17 UTC Type: Bug
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Description Hans de Goede 2014-09-26 18:31:25 UTC 
The first (re)boot after updating F-21 on my laptop (after not updating it for a while) failed to boot, after some debugging I've come to the conclusion, that either a recent glibc change, or a recent intel cpu microcode update has caused me to hit the same issue as documented here.

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=762195

I assume this is caused by a microcode update which now disables hle on haswell while some processes are already using it (e.g. systemd*). As a workaround I've created an /etc/modprobe.conf.d/blacklist.conf file with the following line in there:

blacklist microcode

Which stops the microcode update from applying. Likely the microcode update is disabling hle for a good reason though, and a proper fix would be for glibc to recognize cpu-s with the errata in question and have it not trying to use hle there at all.
Comment 1 Carlos O'Donell 2014-09-26 18:35:17 UTC 
Please test the latest glibc and provide karma so we can push this into f21 quickly.

*** This bug has been marked as a duplicate of bug 1146967 ***