Date: Sat, 19 Jul 2008 09:14:20 -0700
From: Arjan van de Ven <arjan@infradead.org>
To: Daniel Walker <dwalker@mvista.com>
Cc: linux-kernel@vger.kernel.org, mingo@elte.hu
Subject: Re: [patch 1/3] fastboot: Create a "asynchronous" initlevel
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On Sat, 19 Jul 2008 09:08:05 -0700
Daniel Walker <dwalker@mvista.com> wrote:

> On Sat, 2008-07-19 at 08:35 -0700, Arjan van de Ven wrote:
> 
> > > Ok .. I'm not trying to rush you .. With that said, the increased
> > > number of threads seems like a natural direction to take.. I would
> > > assume the returns would diminish depending on the number of
> > > threads per the hardware.. For instance , your addition of one
> > > thread might even harm the boot time on some single core embedded
> > > systems ..
> > 
> > well it still improves the cases where msleep() happens... even on
> > single core. (fwiw the test  machine I reported numbers from is
> > single core, albeit with hyperthreading)
> > 
> 
> How did you measure the boot time? I didn't notice any infrastructure
> for that in the patches..
> 

well.. we already have the printk-timestamps and the initcall_debug
also timestamps individual initcalls...

the way I measured it was based on the printk timestamp of the last
thing the kernel did before giving control to init. (which was a printk
I added just for this purpose)
(and the bootchart tool also confirmed the same data, based on system
uptime)

fwiw I have more patches coming to help boottime once these are done,
but these 3 were self contained and ready for posting, the others need
some more cleanup first.

-- 
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