Comment # 11 on bug 110781 from Richard Thier

Slowdown cause is found when bisecting:

8b3a257851905ff444d981e52938cbf2b36ba830 is the first bad commit
commit 8b3a257851905ff444d981e52938cbf2b36ba830
Author: Marek Olšák <marek.olsak@amd.com>
Date:   Tue Jul 18 16:08:44 2017 -0400

    radeonsi: set a per-buffer flag that disables inter-process sharing (v4)

    For lower overhead in the CS ioctl.
    Winsys allocators are not used with interprocess-sharable resources.

    v2: It shouldn't crash anymore, but the kernel will reject the new flag.
    v3 (christian): Rename the flag, avoid sending those buffers in the BO
list.
    v4 (christian): Remove setting the kernel flag for now

    Reviewed-by: Marek Olšák <marek.olsak@amd.com>