#0  0x000000000056df21 in present_copy_region (drawable=0x1e606e0, pixmap=0x0, 
    update=0x0, x_off=0, y_off=0) at present.c:77
        screen = 0xbb2480
        gc = 0x1394c70
#1  0x000000000056f2b9 in present_execute (vblank=0x25c4c50, ust=461749885, 
    crtc_msc=27204) at present.c:668
        window = 0x1e606e0
        screen = 0xbb2480
        screen_priv = 0xbc56e0
        mode = 0 '\000'
#2  0x000000000056ec8e in present_event_notify (event_id=3625, ust=461749885, msc=27204)
    at present.c:483
        vblank = 0x25c4c50
        tmp = 0x25c4af0
        s = 32767
#3  0x00007f1cf66b350b in vblank_complete (info=0x25c4d60, ust=461749885, msc=27204)
    at sna_present.c:121
        n = 0
#4  0x00007f1cf66b37d9 in sna_fake_vblank_handler (timer=0x2812e10, now=461749, 
    data=0x25c4d60) at sna_present.c:201
        info = 0x25c4d60
        vbl = {request = {type = _DRM_VBLANK_ABSOLUTE, sequence = 27204, signal = 461}, 
          reply = {type = _DRM_VBLANK_ABSOLUTE, sequence = 27204, tval_sec = 461, 
            tval_usec = 749885}}
        msc = 27204
        ust = 461749885
#5  0x000000000061a5db in DoTimer (timer=0x2812e10, now=461749, prev=0x8ba800 <timers>)
    at WaitFor.c:419
        newTime = 0
#6  0x0000000000619efd in WaitForSomething (pClientsReady=0x1d52a40) at WaitFor.c:290
        expired = 1
        tmp_set = {fds_bits = {3635, 12274400, 140736848268096, 139762491350856, 
            9187040, 139762491064320, 12242264, 40533296, 119426464612352, 40533298, 
            140736848268160, 5692969, 4294967296, 0, 140736848268224, 5694867}}
        i = 1
        waittime = {tv_sec = 0, tv_usec = 363}
        wt = 0x7fffd9d90d20
        timeout = 1
        clientsReadable = {fds_bits = {0 <repeats 16 times>}}
        clientsWritable = {fds_bits = {461739383, 2, 12343008, 32750272, 12264576, 
            43316208, 40533024, 27806, 140736848268656, 5707628, 0, 12274400, 0, 
            43942512, 0, 27806}}
        curclient = -640086688
        selecterr = 11
        nready = 0
        devicesReadable = {fds_bits = {27806, 3635, 12274400, 12264576, 12343008, 
            40533040, 140736848268368, 5699865, 0, 0, 0, 1125327634432, 43942384, 
            39944096, 140736848268384, 27567}}
        now = 461749
        someReady = 0
#7  0x0000000000432cb6 in Dispatch () at dispatch.c:358
        clientReady = 0x1d52a40
        result = 0
        client = 0x2c1e620
        nready = -1
        icheck = 0x8bc720 <checkForInput>
        start_tick = 1350
#8  0x0000000000441012 in dix_main (argc=10, argv=0x7fffd9d90f28, envp=0x7fffd9d90f80)
    at main.c:298
        i = 1
        alwaysCheckForInput = {0, 1}
#9  0x00007f1cfba4c790 in __libc_start_main () from /usr/lib/libc.so.6
No symbol table info available.
#10 0x0000000000423829 in _start ()
No symbol table info available.