[Intel-gfx] Fighting tearing

[Roberth Sjonøy]

With the WM I use (xfce WM 4.10.0) with it's compositor, the tearing
is much less, but the little tearing who exist is very noticable.

On Sun, Sep 9, 2012 at 8:00 PM, Chris Wilson <chris at chris-wilson.co.uk> wrote:
> On Sun, 09 Sep 2012 10:55:46 -0700, Ben Widawsky <ben at bwidawsk.net> wrote:
>> On 2012-09-09 08:48, Roberth Sjonøy wrote:
>> > Hello
>> >
>> > I run Arch Linux, with it's latest x.org and kernel, and I have
>> > compiled libdrm and the intel driver from git, and I update it today.
>> >
>> > Buit this is issue exists even with the releases.
>> >
>> > WIth UXA, rendering of the windows in my XFCE4-desktop goes just
>> > fines, good performance, windows (exspecially GTK+) doesn't hang
>> > after
>> > if I drag them over the screen, but there is lot of small tearing.
>> > And I want this to go away, I do not use any kind of composition, and
>> > I am using XFCEs window manager.
>> >
>> > Here is my xorg.conf
>> >
>> >
>> > Section "ServerFlags"
>> >     Option "AutoAddDevices" "Off"
>> > EndSection
>> >
>> > Section "InputDevice"
>> >     Identifier     "Keyboard0"
>> >     Driver         "keyboard"
>> >     Option         "XkbLayout" "no"
>> > EndSection
>> >
>> > Section "Device"
>> >     Identifier  "Card0"
>> >     Driver      "intel"
>> >     Option      "AccelMethod" "UXA"
>> >     Option      "TearFree" "true"
>> >     Option      "MigrationHeuristic" "greedy"
>> >     Option  "TripleBuffer" "true"
>> > EndSection
>> >
>> > With SNA, the performance of the applications is muc much worse. If I
>> > just replace UXA with SNA.
>> >
>> > Thanks in advance for any help.
>> >
>> > Regards,
>> >
>> > Roberth Sjonøy0
>>
>> Unfortunately it's often the case that tearing is pretty much
>> unavoidable without a compositor. AFAIK you'd just be getting lucky with
>> SNA, as opposed to UXA.
>
> Not so. He is explicitly asking for slow tear-free rendering with
> Option "TearFree" "true". On my machines that takes about a 50%
> performance hit which suggests pebkac which is reinforced by the lack
> of information.
> -Chris
>
> --
> Chris Wilson, Intel Open Source Technology Centre