Using powertop I found out that syndaemon wakes up the CPU very often. It uses a polling interval of 20ms. The patch at http://support.zenwalk.org/viewtopic.php?f=5&t=12979 increases this time to 200ms which should be sufficient. Maybe this could be added to the ebuild with an "incpoll"-useflag?
The patch at the Novell bugzilla allows for a configurable polling interval, which would be a better option. https://bugzilla.novell.com/show_bug.cgi?id=386709
Created attachment 160725 [details]
The Novell patch works well and with a setting of syndaemon -m 500 I can lower the number of wakeups from it. I tried this on x86 architecture by applying the patch to the synaptics-0.14.6 ebuild.
Created attachment 160726 [details]
+*synaptics-0.14.6-r3 (30 Jul 2008)
+ 30 Jul 2008; Samuli Suominen <email@example.com>
+ Apply configurable polling interval patch from Novell so that syndaemon
+ doesn't wake up CPU so often. Bug 216679, thanks to Roland Tapken, Thomas
+ Kirchner and Krister Bäckman.