Comment 8 for bug 1550893

Partial backtrace extracted from the core dump:

#0 0x00007fb9e12142c4 in cli_kref_get (bo=0x0, client=0x0) at ../../nouveau/private.h:46
#1 pushbuf_krel (push=0x56502fb22f70, bo=0x0, data=800210280, flags=4, vor=272, tor=800207648)
    at ../../nouveau/pushbuf.c:234
#2 0x00007fb9e121476e in cli_kref_set (bo=0x1, push=0x0, kref=0x0, client=0x5650) at ../../nouveau/private.h:70
#3 nouveau_pushbuf_del (ppush=0x56502fb22f70) at ../../nouveau/pushbuf.c:615
#4 0x000056502fb22f70 in ?? ()
#5 0x0000000000000013 in ?? ()
#6 0x00005650304dd640 in ?? ()
#7 0x000000000000004c in ?? ()
#8 0x000056502ffa4070 in ?? ()
#9 0x00005650300ae2d0 in ?? ()
#10 0x00007fb9e18604be in ?? () from /usr/lib/x86_64-linux-gnu/dri/nouveau_dri.so
#11 0x00007fb9e17bb2bd in ?? () from /usr/lib/x86_64-linux-gnu/dri/nouveau_dri.so
#12 0x0000000000000000 in ?? ()