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Subject: Re: [PATCH 0/14] init: deps: dependency based (parallelized) init
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Cc: linux-kernel@vger.kernel.org, Tomeu Vizoso <tomeu.vizoso@collabora.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Russell King <linux@arm.linux.org.uk>,
        Grant Likely <grant.likely@linaro.org>
From: Alexander Holler <holler@ahsoftware.de>
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Date: Sat, 17 Oct 2015 21:43:17 +0200
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Am 17.10.2015 um 20:38 schrieb Greg Kroah-Hartman:

> So how long does that really take to call all probe functions in all
> possible order?  Real numbers please.  We have the tools to determine
> where at boot time delays are happening, please use them to find the
> problem drivers.

No idea. You might ask Tomeu Vizoso (I've added him to cc) for details 
(or search for the thread "On-demand device registration" where he 
complained that his chromebook boots slow). I've just measured, that 
most my ARM boxes booted faster when I've used the ordering, instead of 
slower through the introduce overhead to order initcalls (without having 
parallelized the initcalls).

Posting times doesn't make much sense, as they heavily depend on the 
configuration. Instead I've posted patches so you can test it yourself.

But if you want a real time, my Netbook with a single core but HT Atom 
N270 boots in one second instead of two to "dmesg | grep Freeing".

Regards,

Alexander Holler