(gdb) thread apply all bt

Thread 1 (Thread 0xb71dd940 (LWP 5505)):
#0  0xb76f2424 in __kernel_vsyscall ()
#1  0xb72027ab in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/i386-linux-gnu/i686/cmov/libpthread.so.0
#2  0xb737d2ac in pthread_cond_wait () from /lib/i386-linux-gnu/i686/cmov/libc.so.6
#3  0xb6afb14c in pipe_semaphore_wait (sema=0xb46cd550) at ../../../../../../../src/gallium/auxiliary/os/os_thread.h:434
#4  radeon_drm_cs_sync_flush (rcs=0xb46ac008) at radeon_drm_cs.c:457
#5  0xb6afbab0 in radeon_drm_cs_flush (rcs=0xb46ac008, flags=10, cs_trace_id=2) at radeon_drm_cs.c:573
#6  0xb6a8f6b9 in r600_context_flush (ctx=ctx@entry=0x96068c0, flags=10, flags@entry=8) at r600_hw_context.c:358
#7  0xb6a90b98 in r600_flush (flags=8, ctx=0x96068c0) at r600_pipe.c:166
#8  r600_flush_gfx_ring (ctx=0x96068c0, flags=8) at r600_pipe.c:199
#9  0xb6a90e81 in r600_flush_from_st (ctx=0x96068c0, fence=0xbfaf5ebc, flags=<optimized out>) at r600_pipe.c:194
#10 0xb688681c in st_flush (st=st@entry=0x96a0620, fence=fence@entry=0xbfaf5ebc, flags=flags@entry=1) at ../../../../src/mesa/state_tracker/st_cb_flush.c:87
#11 0xb68ad614 in st_context_flush (stctxi=0x96a0620, flags=3, fence=0xbfaf5ebc) at ../../../../src/mesa/state_tracker/st_manager.c:459
#12 0xb6af7975 in dri_flush (cPriv=0x9606468, dPriv=0x9613458, flags=3, reason=__DRI2_THROTTLE_SWAPBUFFER) at dri_drawable.c:497
#13 0xb76bde85 in dri2Flush (psc=psc@entry=0x96062f8, ctx=<optimized out>, draw=draw@entry=0x96a5d38, flags=flags@entry=3, throttle_reason=__DRI2_THROTTLE_SWAPBUFFER)
    at dri2_glx.c:570
#14 0xb76be252 in dri2SwapBuffers (pdraw=0x96a5d38, target_msc=0, divisor=0, remainder=0, flush=1) at dri2_glx.c:858
#15 0xb7693a02 in glXSwapBuffers (dpy=0x95f6d18, drawable=696) at glxcmds.c:836
#16 0x08053ba7 in paint_all (ps=0x95f6860, region=29360227, region_real=29360227, t=0x0) at src/compton.c:1931
#17 0x0805d138 in session_run (ps=0x95f6860) at src/compton.c:7176
#18 0x0805d4bc in main (argc=6, argv=0xbfaf6294) at src/compton.c:7275