[Bug 159588] Weird behaviour on KMix start in KDE4 when started with the session

[Christian Esken]

Am Sonntag, 18. Mai 2008 schrieb Thiago Macieira:
> Christian Esken wrote:
> >Am Samstag, 17. Mai 2008 schrieb Thiago Macieira:
> >> Christian Esken wrote:
> >> >read(3,
> >> > "l\2\1\1\n\0\0\0\7\0\0\0=\0\0\0\6\1s\0\5\0\0\0:1.19\0\0\0"..., 2048)
> >> > = 90 read(3, 0x61bdb0, 2048)                 = -1 EAGAIN (Resource
> >> > temporarily unavailable) writev(3,
> >> > [{"l\1\0\1\0\0\0\0\7\0\0\0{\0\0\0\1\1o\0\20\0\0\0/MainApp"..., 144},
> >> > {"", 0}], 2) = 144 poll([{fd=3, events=POLLIN}], 1, 25000) = ?
> >> > ERESTART_RESTARTBLOCK (To be restarted)
> >> >
> >> >My guess was that it is related to KMix being a "KUniqueApplication"
> >> > or KMix accesing the global keyboard shorcut service. It's hard to
> >> > find, as it only happens during session start. Does anybody has a
> >> > idea what is going on, or how to debug this?
> >>
> >> Can you run this again with -s 2048? If you can include timestamps
> >> too, it would be great.
> >
> >OK, here we go: Available at
> > https://bugs.kde.org/attachment.cgi?id=24828&action=view
> 
> Both traces in that attachment are identical, except for the PID of the 
> forked process on line 588. If it weren't for that, I'd have said that 
> someone attached the same file twice by mistake.
> 
> They both indicate a fork(), a connection to D-Bus, setup, a call to the 
> new application then a call to newInstance.
> 
> Without timestamps there's no way of telling whether there was a pause or 
> not.
> 

There is now some feedback with timestamps in bko. We really see a pause: there is a poll() that takes 16 seconds. 

19:50:49.494632 poll([{fd=4, events=POLLIN}, {fd=6, events=POLLIN}, {fd=11, events=POLLIN}, {fd=10, events=POLLIN, revents=POLLIN}, {fd=3, events=POLLIN}, {fd=15, events=POLLIN}, {fd=14, events=POLLIN}], 7, 29150) = 1 <16.824485> 
19:51:06.319284 ioctl(10, FIONREAD, [32]) = 0 <0.000012>

I did a some analysis in http://bugs.kde.org/show_bug.cgi?id=159588#c22 . But at that point I need some help with understanding what happens after that - I see some DBUS communcation, but cannot interpret it.

   Christian

-- 
Things should be made as simple as possible, but no simpler. 
  - Albert Einstein