Q: Cramfs Vs. Ubifs

[Ran Shalit]

>> I wonder why I didn't find any information about disadvantage of using
>> ubifs as root file system in embedded system in terms of access to
>> flash during application life.
>>
>I think because it normally is not a problem. Also, the same goes for any file system which resides on the flash, it's not a ubifs-specific problem.
>
> This isn't an issue specific to UBIFS.  Look into mlock/mlockall if your
> application needs to avoid latencies associated with demand-paging from
> flash or any other storage.
>
Can you please elaborate why accessing the flash while main "real-time
application" is running it is not a problem. I also read in
free-electrons tutorial on embedded linux such recommendation for
using file system such as cramfs, ubifs, which also access the flash
during execution.
Why is it not a problem for embedded linux ? From my experience with
other embedded OS, it is not recommended to access flash during
execution.
Many thanks, Ran