2012-02-02 02:40:36

by john stultz

[permalink] [raw]
Subject: Re: [PATCH] clocksource: Load the ACPI PM clocksource asynchronously

On Mon, 2012-01-30 at 20:51 -0800, Arjan van de Ven wrote:
> From ef4b0d23878277dfd75828f13353e605aae2937f Mon Sep 17 00:00:00 2001
> From: Arjan van de Ven <[email protected]>
> Date: Mon, 30 Jan 2012 20:23:30 -0800
> Subject: [PATCH] clocksource: Load the ACPI PM clocksource asynchronously
>
> The ACPI clocksource takes quite some time to initialize,
> and this increases the boot time of the kernel for a
> double digit percentage. This while almost all modern
> systems will be using the HPET already anyway.
>
> This patch turns the clocksource loading into an asynchronous
> operation; which means it won't hold up the boot while
> still becoming available normally.
>
> To make this work well, an udelay() had to be turned into an
> usleep_range() so that on UP systems, we yield the CPU to
> regular boot tasks instead of spinning.
>
> CC: John Stultz <[email protected]>
> CC: Thomas Gleixner <[email protected]>
> CC: Len Brown <[email protected]>
>
> Signed-off-by: Arjan van de Ven <[email protected]>


Looks good to me. I've gone ahead and queued it

thanks
-john