Benchmark of Wayland

Justin Lee justinlee5455 at
Wed Nov 17 18:56:26 PST 2010

2010/11/18 microcai <microcai at>:
> 2010/11/18 Justin Lee <justinlee5455 at>
>> This kind of latency due to OS scheduling could be eliminated by
>> direct-procedure call. That is, the client passes the GEM buffer to
>> the server just like it passes the GEM buffer as an argument to a
>> function. In this approach, the compositor is not a process. Rather,
>> the compositor is just a function live in the client program. So there
>> will be no context switches.
> So ? Move wayland entirely into the kernel ? Then there will be no delay.

No, I don't think so. The necessary infrastructure have been there in
the kernel (i.e. DRM, GEM, KMS). I don't think we should bother
writing kernel code which is error-prone and need specific care to
avoid bugs and instability. Besides, I don't think moving Wayland into
the kernel will be any beneficial if we could do all the same thing in
user space.

I pointed out the latency because I don't want to see any lag when I
scroll down a web page in my browser. I have noticed that in X when I
dragged down the scroll bar in browser, the scroll bar wasn't tied to
the mouse pointer and the scroll bar fell behind the mouse pointer.
When the scroll bar was dragged down, the web page wasn't updated
immediately. Instead, the page got updated until a small period of
time was passed after the drag happened.

This kind of issue would be solved in direct-procedure call approach,
because  function call is synchronized. The function get executed
right away after the caller calls it. It is the most *direct* manner I
can think of.

> And that's probably what MacOSX and Windows NT does. As far as I know,
> Darwin uses quantz (AGL?)  as basis of their GUI system , but WIndows NT
> uses bullshit GDI .....

<<<bullsh*t>>> GDI?????
Sounds like you are radical Microsoft hater. Yeah, many Linux users
hate MS, but there is no need to be so radical in a mailing list which
is unrelated to MS. ...I mean there are many MS forums on the net, you

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