Bug 139463 - Spinning on rhgb-console
Spinning on rhgb-console
Product: Fedora
Classification: Fedora
Component: rhgb (Show other bugs)
All Linux
medium Severity medium
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Assigned To: Daniel Veillard
Depends On:
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Reported: 2004-11-15 22:43 EST by Owen Taylor
Modified: 2007-11-30 17:10 EST (History)
2 users (show)

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Fixed In Version:
Doc Type: Bug Fix
Doc Text:
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Clone Of:
Last Closed: 2004-11-29 08:15:40 EST
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RHEL 7.3 requirements from Atomic Host:
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Description Owen Taylor 2004-11-15 22:43:57 EST

reveals that rhgb spins at 100% cpu during boot. Some inspection
of the source code reveals this is do to the handling of
rhgb-console... it calls poll() on a fifo ... and fifo's have
the behavior that once the last writer closes the fifo, it 
reports HUP until a new reader opens it.

Googling on the topic reveals:


with an IRC snippet from myself about the topic. 

Two possible workarounds are suggested there:

 - Close the fifo and reopen it ...doesn't work here since
   we might lose data

 - open the fifo read/write so there are never 0 writers.

Basically, my conclusion has always been that fifo's are just
evil, poorly defined creatures. I think the O_RDWR hack will
work, at least on linux. I'm not sure it wouldn't be long
term to replace '> /etc/rhgb/temp/rhgb-console' with
'| rhgb-client --echo' or something.
Comment 1 Daniel Veillard 2004-11-16 04:10:32 EST
I see, ouch ... I will try to fix ASAP.

Comment 2 Brian Long 2004-11-29 07:54:49 EST
I assume this also affects RHEL 3 U2 and beyond since rhgb is now
included.  Is that correct?  Will an update to rhgb be available
before U5?
Comment 3 Daniel Veillard 2004-11-29 08:14:10 EST
RHEL 3 U2 seems to use rhgb-0.11.2 which is not affected by that bug.
Updating to the latest doesn't sound resonnable it would require to
upgrade a number of other pieces.

Comment 4 Daniel Veillard 2004-11-29 08:15:40 EST
The original bug has been fixed with a FC3 update rhgb-0.15.1


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