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On Fri, Sep 22, 2006 at 01:06:48PM +0000, Pavel Machek wrote: > > would be nice to merge the -hrt queue that goes right ontop this queue. > > Even if HIGH_RES_TIMERS is "default n" in the beginning. That gives us > > high-res timers and dynticks which are both very important features to > > certain classes of users/devices. > > dynticks give benefit of 0.3W, or 20minutes (IIRC) from 8hours on thinkpad > x60... and they were around for way too long. (When baseline is > hz=250, it is 0.5W from hz=1000 baseline). It would be cool to > finally merge them. I actually saw much bigger wins when I tested with an Athlon XP based compaq laptop a year or so back. dynticks moved idle from being stuck at 21W to a sinusoidal cycle in single watt increments between 22W->18W. It would never stay in the lower ranges for long because of timers firing all the time. See http://kernelslacker.livejournal.com/33637.html for details. There is much interest right now in fixing up various bits of userspace to not do braindead things with timers/polling. The gnome people have recently come up with a timertop-esque hack (that goes a bit further) for eg. See http://blogs.gnome.org/ryanl for details. Arjan also recently did battle with a huge amount of really dumb userspace, and dwmw2 has been tracking a bunch of these for OLPC: https://bugzilla.redhat.com/bugzilla/showdependencytree.cgi?id=204948 Damn all these busy people making me feel inadequate :) Dave - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ | ||||||||||||
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