PPC 266MHz 8347E slow kernel decompress

[Christian Melki]

Hi.


I recently upgraded one of Ericssons platforms from a old 3.6.x to the latest 3.16.x LTS kernel.
It was a smooth upgrade, besides kernel decompression taking much longer to complete. From like 2 seconds to 10-12 seconds.
I also tried a 4.10.z kernel with the same result.
The decompression code doesn't have any significant changes as far as I can see. Maybe I am looking in the wrong place?
Did the ppc arch init change between 3.6.x and 3.16.x? I am thinking of cache init, prefetch copy functions etc?
The old Redboot loader starts the kernel with caches off. Maybe the older init re-initialized the caches before decompression?
Bootloader is identical, so is the compiler. Nothing has changed besides the kernel itself.
It is 1.5M or so, no external modules. Runtime speed after decompression seems absolutely normal.
I couldn't find anything significant anywhere regarding this.


Hints would be much appreciated.


Regards,

Christian
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.ozlabs.org/pipermail/linuxppc-dev/attachments/20170620/602617db/attachment-0001.html>