** Summary changed:
- Something blocks compiz randomly several times per day
+ Disabling an output can cause vblank events to be missed
** Description changed:
+ When an output gets disabled - by being switched off by DPMS, unplugged,
+ etc - it's possible for applications to have pending vblank events
+ waiting on this output. If this occurs, the application will never
+ receive the vblank event. This manifests as the app appearing to hang
+ (in poll() on the X connection, if you attach GDB).
+
Binary package hint: compiz
This seems to happen when I'm not at my laptop (ie, when the screensaver
has activated usually). When I return to my laptop, I find it in a state
which appears to be completely frozen (ie, nothing gets repainted on the
screen). However, I can switch to a console and things appear to be
working normally. I can send a SIGKILL to compiz and start another WM,
and then everything starts working normally again (although if I restart
compiz, it often crashes until I've restarted my laptop).
If I attach gdb to the hung compiz, I always see a trace which looks
like this:
0x00007f53f3dc8e33 in __poll (fds=<value optimised out>, nfds=<value
optimised out>, timeout=<value optimised out>) at
../sysdeps/unix/sysv/linux/poll.c:87
87 ../sysdeps/unix/sysv/linux/poll.c: No such file or directory.
- in ../sysdeps/unix/sysv/linux/poll.c
+ in ../sysdeps/unix/sysv/linux/poll.c
(gdb) bt[K[Kbt full
#0 0x00007f53f3dc8e33 in __poll (fds=<value optimised out>, nfds=<value
optimised out>, timeout=<value optimised out>) at
../sysdeps/unix/sysv/linux/poll.c:87
- resultvar = 18446744073709551100
- oldtype = 0
- result = <value optimised out>
+ resultvar = 18446744073709551100
+ oldtype = 0
+ result = <value optimised out>
#1 0x00007f53f738d512 in _xcb_conn_wait (c=0x1b79060, cond=<value optimised
out>, vector=0x0, count=0x0) at ../../src/xcb_conn.c:313
- ret = <value optimised out>
- fd = {fd = 3, events = 1, revents = 0}
+ ret = <value optimised out>
+ fd = {fd = 3, events = 1, revents = 0}
#2 0x00007f53f738eb3f in xcb_wait_for_reply (c=0x1b79060, request=390272,
e=0x7fff56067648) at ../../src/xcb_in.c:378
- cond = {__data = {__lock = 0, __futex = 0, __total_seq = 0,
__wakeup_seq = 0, __woken_seq = 0, __mutex = 0x0, __nwaiters = 0,
__broadcast_seq = 0},
- __size = '\000' <repeats 47 times>, __align = 0}
- reader = {request = 390272, data = 0x7fff560675a0, next = 0x0}
- prev_reader = <value optimised out>
- widened_request = <value optimised out>
- ret = 0x0
+ cond = {__data = {__lock = 0, __futex = 0, __total_seq = 0,
__wakeup_seq = 0, __woken_seq = 0, __mutex = 0x0, __nwaiters = 0,
__broadcast_seq = 0},
+ __size = '\000' <repeats 47 times>, __align = 0}
+ reader = {request = 390272, data = 0x7fff560675a0, next = 0x0}
+ prev_reader = <value optimised out>
+ widened_request = <value optimised out>
+ ret = 0x0
#3 0x00007f53f75e188d in _XReply (dpy=0x1b77e10, rep=0x7fff560676a0,
extra=0, discard=0) at ../../src/xcb_io.c:533
- req = 0x1b74780
- response = <value optimised out>
- error = 0x0
- c = 0x1b79060
- reply = <value optimised out>
- current = 0x1b74780
- __PRETTY_FUNCTION__ = "_XReply"
+ req = 0x1b74780
+ response = <value optimised out>
+ error = 0x0
+ c = 0x1b79060
+ reply = <value optimised out>
+ current = 0x1b74780
+ __PRETTY_FUNCTION__ = "_XReply"
#4 0x00007f53efb6993b in DRI2WaitMSC (dpy=0x1b77e10, drawable=100,
target_msc=0, divisor=2, remainder=1, ust=0x7fff56067728, msc=0x7fff56067720,
sbc=0x7fff56067718) at dri2.c:616
- info = <value optimised out>
- req = <value optimised out>
- rep = {type = 64 '@', pad1 = 119 'w', sequenceNumber = 22022, length
= 32767, ust_hi = 1443264328, ust_lo = 32767, msc_hi = 100, msc_lo = 0, sbc_hi
= 2137562112,
- sbc_lo = 3119085452}
- #5 0x00007f53efb67df1 in dri2WaitForMSC (pdraw=<value optimised out>,
target_msc=<value optimised out>, divisor=<value optimised out>,
remainder=<value optimised out>,
- ust=0x7fff56067778, msc=0x7fff56067770, sbc=0x7fff56067768) at
dri2_glx.c:346
- dri2_ust = 29839872
- dri2_msc = 29878048
- dri2_sbc = 139998480560225
- ret = -516
+ info = <value optimised out>
+ req = <value optimised out>
+ rep = {type = 64 '@', pad1 = 119 'w', sequenceNumber = 22022, length
= 32767, ust_hi = 1443264328, ust_lo = 32767, msc_hi = 100, msc_lo = 0, sbc_hi
= 2137562112,
+ sbc_lo = 3119085452}
+ #5 0x00007f53efb67df1 in dri2WaitForMSC (pdraw=<value optimised out>,
target_msc=<value optimised out>, divisor=<value optimised out>,
remainder=<value optimised out>,
+ ust=0x7fff56067778, msc=0x7fff56067770, sbc=0x7fff56067768) at
dri2_glx.c:346
+ dri2_ust = 29839872
+ dri2_msc = 29878048
+ dri2_sbc = 139998480560225
+ ret = -516
#6 0x00007f53efb3f81f in __glXWaitVideoSyncSGI (divisor=2, remainder=1,
count=0x7fff560677cc) at glxcmds.c:1775
- gc = 0x1c7e720
- psc = 0x1c77560
- pdraw = <value optimised out>
- ust = 2722
- msc = <value optimised out>
- sbc = 139998480562447
- ret = <value optimised out>
+ gc = 0x1c7e720
+ psc = 0x1c77560
+ pdraw = <value optimised out>
+ ust = 2722
+ msc = <value optimised out>
+ sbc = 139998480562447
+ ret = <value optimised out>
#7 0x00007f53efdb71c4 in PrivateGLScreen::waitForVideoSync() () from
/usr/lib/compiz/libopengl.so
No symbol table info available.
#8 0x00007f53efdb737b in
PrivateGLScreen::paintOutputs(std::list<CompOutput*,
std::allocator<CompOutput*> >&, unsigned int, CompRegion const&) ()
- from /usr/lib/compiz/libopengl.so
+ from /usr/lib/compiz/libopengl.so
No symbol table info available.
#9 0x00007f53effddb19 in CompositeScreen::paint(std::list<CompOutput*,
std::allocator<CompOutput*> >&, unsigned int) () from
/usr/lib/compiz/libcomposite.so
No symbol table info available.
#10 0x00007f53effdf930 in CompositeScreen::handlePaintTimeout() () from
/usr/lib/compiz/libcomposite.so
No symbol table info available.
#11 0x00000000004219ff in CompTimeoutSource::callback() ()
No symbol table info available.
#12 0x000000000042146d in CompTimeoutSource::dispatch(sigc::slot_base*) ()
No symbol table info available.
#13 0x00007f53f5c649df in Glib::Source::dispatch_vfunc(_GSource*, int
(*)(void*), void*) () from /usr/lib/libglibmm-2.4.so.1
No symbol table info available.
#14 0x00007f53f5114bcd in g_main_dispatch (context=0x1ba7730) at
/build/buildd/glib2.0-2.28.3/./glib/gmain.c:2440
- dispatch = 0x7f53f5c64990 <Glib::Source::dispatch_vfunc(_GSource*,
int (*)(void*), void*)>
- was_in_call = 0
- user_data = 0x1c507a0
- callback = 0x7f53f5c64b40
- cb_funcs = 0x7f53f53bf630
- cb_data = 0x1c45fe0
- current_source_link = {data = 0x1c50730, next = 0x0}
- need_destroy = <value optimised out>
- source = 0x1c50730
- current = 0x1ba7e90
- i = <value optimised out>
+ dispatch = 0x7f53f5c64990 <Glib::Source::dispatch_vfunc(_GSource*,
int (*)(void*), void*)>
+ was_in_call = 0
+ user_data = 0x1c507a0
+ callback = 0x7f53f5c64b40
+ cb_funcs = 0x7f53f53bf630
+ cb_data = 0x1c45fe0
+ current_source_link = {data = 0x1c50730, next = 0x0}
+ need_destroy = <value optimised out>
+ source = 0x1c50730
+ current = 0x1ba7e90
+ i = <value optimised out>
#15 g_main_context_dispatch (context=0x1ba7730) at
/build/buildd/glib2.0-2.28.3/./glib/gmain.c:3013
No locals.
#16 0x00007f53f51153a8 in g_main_context_iterate (context=0x1ba7730,
block=<value optimised out>, dispatch=1, self=<value optimised out>)
- at /build/buildd/glib2.0-2.28.3/./glib/gmain.c:3091
- max_priority = 2147483647
- timeout = 11
- some_ready = 1
- nfds = 14
- allocated_nfds = <value optimised out>
- fds = <value optimised out>
+ at /build/buildd/glib2.0-2.28.3/./glib/gmain.c:3091
+ max_priority = 2147483647
+ timeout = 11
+ some_ready = 1
+ nfds = 14
+ allocated_nfds = <value optimised out>
+ fds = <value optimised out>
#17 0x00007f53f51159f2 in g_main_loop_run (loop=0x1c50880) at
/build/buildd/glib2.0-2.28.3/./glib/gmain.c:3299
- __PRETTY_FUNCTION__ = "g_main_loop_run"
+ __PRETTY_FUNCTION__ = "g_main_loop_run"
#18 0x0000000000429fba in CompScreen::eventLoop() ()
No symbol table info available.
#19 0x0000000000422f70 in main ()
This is happening fairly often for me (3-4 times per day)
--
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
https://bugs.launchpad.net/bugs/740126
Title:
Disabling an output can cause vblank events to be missed
--
ubuntu-bugs mailing list
ubuntu-bugs@lists.ubuntu.com
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
