Openmoko Bug #1597: after a long suspend time, kernel thread events/0 sits eating 30% cpu

[Openmoko Public Trac]

#1597: after a long suspend time, kernel thread events/0 sits eating 30% cpu
--------------------------------+-------------------------------------------
    Reporter:  raster           |        Owner:  zecke     
        Type:  defect           |       Status:  in_testing
    Priority:  normal           |    Milestone:            
   Component:  System Software  |      Version:            
    Severity:  major            |   Resolution:            
    Keywords:                   |    Blockedby:            
Reproducible:                   |     Blocking:            
--------------------------------+-------------------------------------------

Comment(by h.koenig):

 Replying to [comment:21 koe]:
 > I've also added my dmesg output, it seems that there where no unexpected
 messages after booting.

 right now I see the same problem (looping events/0) for the first time
 running this kernel:

 root at om-gta02:~# opkg list_installed kernel
 kernel - 2:2.6.24+git75965+cb3cc53a76c7f1f7c827d048db7a849e77071515-r1.01
 -

 root at om-gta02:~# cat /proc/version
 Linux version 2.6.24 (build at barbie) (gcc version 4.1.2) #1 PREEMPT Tue Aug
 26 08:33:29 CST 2008


 the FR was running all night (suspend disabled) waiting for the Xglamo
 looping problem (on devel list see subject: Xglamo loops and hangs), but
 this morning both Xglamo and events/0 loop:


 Cpu(s): 22.0%us, 75.2%sy,  0.0%ni,  0.3%id,  0.0%wa,  0.0%hi,  2.5%si,
 0.0%st
 Mem:    123856k total,   121796k used,     2060k free,       24k buffers
 Swap:        0k total,        0k used,        0k free,    12240k cached

   PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
  1513 root      19  -1 12784 4020  824 R 49.1  3.2 166:19.26 Xglamo
     5 root      15  -5     0    0    0 S 30.5  0.0 507:27.27 events/0
  1468 root       9 -11 18704 3012  420 S 11.0  2.4 383:22.12 pulseaudio

 if I SIGSTOP Xglamo, top output looks like this:


 Cpu(s):  6.9%us, 41.0%sy,  0.0%ni, 50.0%id,  0.0%wa,  0.0%hi,  2.1%si,
 0.0%st
 Mem:    123856k total,   121860k used,     1996k free,       24k buffers
 Swap:        0k total,        0k used,        0k free,     5500k cached

   PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
     5 root      15  -5     0    0    0 R 30.5  0.0 507:54.49 events/0
  1468 root       9 -11 18704 3012  420 S 10.9  2.4 383:30.47 pulseaudio
  6618 root      20   0  2396 1148  904 R  4.7  0.9   0:01.71 top



 and here is the Xglamo traceback:

 (gdb) where
 #0  0x00014f10 in GLAMOEngineWaitReal ()
 #1  0x000152e4 in GLAMOFlushCMDQCache ()
 #2  0x00015ee4 in GLAMOBlockHandler ()
 #3  0x0001ee8c in BlockHandler ()
 #4  0x000edaa4 in WaitForSomething ()
 #5  0x000381b4 in Dispatch ()
 #6  0x000223e8 in main ()
 (gdb)



 in dmesg I get lots of these messages:

 [220492.240000] ar6000_ioctl_giwscan(): data length 0
 [220507.270000] ar6000_ioctl_giwscan(): data length 0
 [220523.220000] ar6000_ioctl_giwscan(): data length 0
 [220539.200000] ar6000_ioctl_giwscan(): data length 0
 [220555.200000] ar6000_ioctl_giwscan(): data length 0


 any more data I can provide ?


 is it possible to reset or stop that events/0 thread without rebooting ?

 just in case it might be helpful to further debug the Xglamo process which
 is stuck too....

-- 
Ticket URL: <https://docs.openmoko.org/trac/ticket/1597#comment:22>
docs.openmoko.org <http://docs.openmoko.org/trac/>
openmoko trac