[mythtv-commits] Ticket #10201: mythfrontend: invalid fastbin entry

[MythTV]

#10201: mythfrontend: invalid fastbin entry
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 Reporter:  Chad Sawatzky <chad.sawatzky@…>      |          Owner:
     Type:  Bug Report - Crash                   |         Status:
 Priority:  minor                                |  assigned
Component:  MythTV - Video Playback              |      Milestone:  unknown
 Severity:  medium                               |        Version:  0.24.1
 Keywords:  mythfrontend playback livetv         |     Resolution:
  recordings                                     |  Ticket locked:  0
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Comment (by Chad Sawatzky <chad.sawatzky@…>):

 Here is an update...

 I have tried the playback profiles Slim and VDPAU Slim.  Both settings
 continued to result in the same error.  I noticed that the setting I had
 was similar to Slim, but with the higher rez using vdpau.

 I while doing some reading on free and malloc I noticed that MALLOC_CHECK_
 can be set in the environ.  I have been running mythfrontend with
 MALLOC_CHECK_=1.  This makes the glibc memory checking ignore some
 detected errors.

 "...if set to 1, a diagnostic message is printed on stderr..."

 I've been running like this for about 2 weeks and this has eliminated the
 crashing I was experiencing.  I was still expecting to see a fastbin
 error, but I have not seen one while running with MALLOC_CHECK_=1.

 Although this does not resolve the root cause, it does make running
 mythfrontend far more usable for me. Since this was a free() error, I was
 wondering if I might end up with a memory leak so I ran a check on memory
 use by mythfrontend every hour for 4 days.  I didn't see any memory leak
 running it this way, the memory usage look stable.

 When exiting mythfrontend after running for a few days I ended up with a
 segfault in libQtCore.  I'm not sure if this would be related or just some
 stray event.  I have not seen it happen since.
 {{{
 Feb  4 00:33:13 htpc kernel: [352223.369133] mythfrontend[2507]: segfault
 at 24 ip 45823db6 sp b19debd0 error 4 in
 libQtCore.so.4.8.0[4569f000+2d8000]
 Feb  4 00:33:13 htpc lircd-0.9.0[1154]: removed client
 Feb  4 00:33:26 htpc abrtd: Directory 'ccpp-2012-02-04-00:33:13-2490'
 creation detected
 Feb  4 00:33:26 htpc abrt[23389]: Saved core dump of pid 2490
 (/usr/bin/mythfrontend) to /var/spool/abrt/ccpp-2012-02-04-00:33:13-2490
 (432857088 bytes)
 }}}

 I'm not sure if this is somehow related to my specific combination of
 hardware or software (like libQtcore or glibc) or what is going on.  In
 searching for more information I've concluded that I may be the only one
 experiencing this particular error.  If you're interested (not sure if it
 will help) you can find my hw profile here
 http://www.smolts.org/client/show_all/pub_443bc76a-
 cb20-4511-ba20-c0fb8bf6d19e

 I was thinking that it might be time to try using valgrind.  If I do, I
 will provide an update if there is anything interesting.

 If there is anything more you can think for me to try or information you
 would like, please let me know.  I will continue to investigate to see if
 there is something more I can learn, though for now at least I seem to
 have found a way stabilize my setup.

 Thanks
 --CS

-- 
Ticket URL: <http://code.mythtv.org/trac/ticket/10201#comment:5>
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