XMir hung in xf86CrtcSetModeTransform()

[Daniel van Vugt]

Using the latest ppa:mir-team/qa-testing2 multimonitor was working very nicely for a few minutes, but then the X server hung:

#0 pthread_cond_wait@@GLIBC_2.3.2 ()
    at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
185 in ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S
#0 pthread_cond_wait@@GLIBC_2.3.2 ()
    at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1 0x00007f2a1143d1ec in std::condition_variable::wait(std::unique_lock<std::mutex>&) () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#2 0x00007f2a12064e6b in MirWaitHandle::wait_for_all() ()
   from /usr/lib/x86_64-linux-gnu/libmirclient.so.2
#3 0x00007f2a122a0291 in ?? ()
   from /usr/lib/xorg/modules/extensions/libxmir.so
#4 0x00007f2a15bf17fa in xf86CrtcSetModeTransform ()
#5 0x00007f2a15bfad26 in ?? ()
#6 0x00007f2a15c37cba in RRCrtcSet ()
#7 0x00007f2a15c39108 in ProcRRSetCrtcConfig ()
#8 0x00007f2a15b7cfce in ?? ()
#9 0x00007f2a15b6c52a in ?? ()
#10 0x00007f2a13864de5 in __libc_start_main (main=0x7f2a15b6c160, argc=11,
    ubp_av=0x7fff53642628, init=<optimised out>, fini=<optimised out>,
    rtld_fini=<optimised out>, stack_end=0x7fff53642618) at libc-start.c:260
#11 0x00007f2a15b6c86f in _start ()

ii xserver-common 2:1.14.2.901-2ubuntu3+xmirMM13 all common files used by various X servers
ii xserver-xephyr 2:1.14.2.901-2ubuntu3+xmirMM13 amd64 nested X server
ii xserver-xorg-core 2:1.14.2.901-2ubuntu3+xmirMM13 amd64 Xorg X server - core server
ii xserver-xorg-video-intel 2:2.21.14-4ubuntu2+xmirMM6 amd64 X.Org X server -- Intel i8xx, i9xx display driver
ii xserver-xorg-video-nouveau 1:1.0.8-0ubuntu3+xmirMM2 amd64 X.Org X server -- Nouveau display driver
ii xserver-xorg-xmir 2:1.14.2.901-2ubuntu3+xmirMM13 amd64 Xorg - the X.Org X server (module for running nested in Mir)

[Daniel van Vugt (vanvugt)]

It is just the X server that's hung. I can still ssh in and start native Mir clients which run fine on top of the frozen X.

[Daniel van Vugt (vanvugt)]

Incomplete. Not seen for a while. But I also haven't really stress tested multimonitor for a while.

[Daniel van Vugt (vanvugt)]

XMir 1.0 (the old Xorg extension) is now deprecated and is not being maintained or fixed. It is replaced by the new 'Xmir' binary (package 'xmir') introduced in Ubuntu 15.10 wily.