[PATCH] reduce wakeups from smart scheduler

[Kristian Høgsberg]

On Oct 29, 2007 11:44 PM, Arjan van de Ven <arjan at infradead.org> wrote:
> >From 48e4d08e99de41047c6b6fde5ba9d12787881c23 Mon Sep 17 00:00:00 2001
> From: Arjan van de Ven <arjan at linux.intel.com>
> Date: Sun, 28 Oct 2007 09:37:52 +0100
> Subject: [PATCH]  reduce wakeups from smart scheduler
>
> The smart scheduler itimer currently always fires after each request
> (which in turn causes the CPU to wake out of idle, burning precious
> power). Rather than doing this, just stop the timer before going into
> the select() portion of the WaitFor loop. It's a cheap system call, and
> it will only get called if there's no more commands batched up from the
> active fd.

This patch breaks the dumbScheduler for me, which is how I usually
debug the X server.  When I start the X server as

  ./Xorg -dumbSched

it dies from an unhandled SIGALARM shortly after startup.

cheers,
Kristian