Re: [dev] [dwm] Avoid requesting MotionNotify events

From: Alexander Monakov <amonakov_AT_ispras.ru>
Date: Sat, 16 Jul 2016 19:08:04 +0300 (MSK)

On Sat, 16 Jul 2016, Staven wrote:
> On Sat, Jul 16, 2016 at 02:33:18PM +0300, Alexander Monakov wrote:
> > This causes lots of useless communication between the X server and dwm every
> > time the mouse pointer is moved, even when nothing could possibly change as
> > a result (e.g. if Xinerama is not compiled in, or only one monitor is present).
> > On my system, the resulting syscalls-per-second count in dwm is about 490, if
> > the mouse if moved continuously.
>
> Why is this a problem?
> I mean, I just found out that I wiggle my cursor really hard, dwm CPU usage
> goes up to 3%. Is that why?

Yes, that is why. As to why this is a problem, it's a kind of software bloat,
just not in static code size, but rather in runtime cost (that wasn't always
present, but appeared when a feature was added). Given that the issue is not
very hard to avoid, I decided to raise it on the mailing list and propose my
solutions.

Alexander
Received on Sat Jul 16 2016 - 18:08:04 CEST