X input event generation thread (v2)

[Alan Coopersmith]

Adam Jackson wrote:
> On Tue, 2010-09-28 at 23:00 +0200, Mark Kettenis wrote:
>> Of course the same problem exists with SIGIO.  After realizing how
>> much code was run from the SIGIO signal handler, and the VGA arbiter
>> issues related to that we decided to disable SIGIO on OpenBSD
>> (encouraged by Alan C.'s statement that Solaris does the same).  As
>> far as I can tell, the only effect of this is that it disables the
>> "silken mouse".  Quite a few OpenBSD users tested that change, and all
>> of them indicated that they noticed no difference whatsoever.
> 
> Your users are clearly not sensitive to input latency.  Mine are.  

My users were used to not having SIGIO, since we disabled SIGIO within a
couple months of first delivering a version that actually had a Solaris
implentation.   We also have a very different kernel scheduler - I don't
know how much that affects things.

Certainly in years past, this sort of thing was important to Sun, since
we had a kernel level implementation in Solaris on SPARC, but that required
kernel frame buffer devices implementing a common set of hardware cursor
ioctls that we could call to move the pointer image from a streams module
pushed onto the mouse device, bypassing the server altogether until you
crossed out of the bounding rectangle passed down by the server.  But that
was the days when users had 25Mhz SPARC cpu's, not 2.5 Ghz x64.

-- 
	-Alan Coopersmith-        alan.coopersmith at oracle.com
	 Oracle Solaris Platform Engineering: X Window System