[PATCH 1/2] MTD: UBI: speed up init by moving status messages to debugfs

[Rajeev Kumar]

Richard

On 07/25/2016 04:01 PM, Richard Weinberger wrote:
> Rajeev,
>
> Am 25.07.2016 um 11:46 schrieb Rajeev Kumar:
>> This patch simply moves the verbose status messages associated with
>> UBI's fastmap feature to debugfs, thereby decreasing UBI
>> initialization time from 97 mS to 16 mS. Note that the first time
>> fastmap is invoked, building the fastmap took 146 mS. In order to
>> reproduce the test conditions, build with CONFIG_MTD_UBI_FASTMAP=y and
>> CONFIG_DYNAMIC_DEBUG=y and append the following to bootargs:
>>
>> initcall_debug ubi.mtd=0 ubi.fm_autoconvert=1
>>
>> ubi.mtd=0 is needed at every boot if you want ubi to be
>> autoloaded. ubi.fm_autoconvert switch is needed only once, when
>> fastmap is created.
>
> So, you're working on a system which has to boot as fast as possible
> and writing kernel logs hurts the performance. (Slow UART?)
> Why do you change logging only in UBI (Fastmap)? Many other subsystems
> print during boot and would also hurt the performance.
> In such a situation I'd assume that changing the kernel log level or
> using the quiet kernel parameter would help more.
>

Agreed, but the question is do we really need these all values for 
UBI(Fastmap) on console every time system is booted ?

Thanks
~Rajeev

> Thanks,
> //richard
>