Current Bootchart

Wolfgang Spraul wolfgang at openmoko.com
Mon Jul 7 15:59:53 CEST 2008


Graeme,

> I already did all this work.
> pre-initing udev with static devices saves 10s on boot time.
> Using mdev -s to pre-init also saves 10s on boot time.

Is this improvement in the daily build images we can download from  
buildhost?
Wolfgang

On Jul 7, 2008, at 6:04 PM, Graeme Gregory wrote:

> On Mon, Jul 07, 2008 at 11:59:09AM +0200, Dr. H. Nikolaus Schaller  
> wrote:
>> As far as I understood the documentation it serializes events from
>> hotplug. So each hotplugged device has to wait for its predecessor.
>>
>> But what is hotplugged in the OM during boot? It looks like boot
>> initialization is treated as hot-plugging. Appears to be similar to
>> ldconfig which has a cache that does NOT need updates on boot.
>>
>> * the first idea I have is to preinitialize devices by copying some
>> files so that hotplug/udev hasn't to do so much work (i.e. taking a
>> snapshot of the important files AFTER udev did run once, and provide
>> that snapshot as part of the rootfs)
>> * or, if that does not work, only hotplug those devices that are
>> essential for booting and postpone other until the GUI is running.
>>
>> Since I am not a kernel specialist, I have no idea whether that  
>> works...
>>
> No-one reads my mails :-(
>
> I already did all this work.
>
> pre-initing udev with static devices saves 10s on boot time.
>
> Using mdev -s to pre-init also saves 10s on boot time.
>
> I prefer to use mdev as at least we dont need to play funny tricks to
> get the SD card to work on boot.
>
> Graeme
>
>




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