GEOM_ULZMA

[Alexandr Rybalko]

On Thu, 4 Mar 2010 17:31:18 +0800
Adrian Chadd <adrian at freebsd.org> wrote:

>> On 4 March 2010 00:29, Tim Kientzle <kientzle at freebsd.org> wrote:
>> 
>> > Interesting question:  What is the impact on boot speed?
>> > It could be a lot faster to load 5MB from disk and
>> > decompress to a 24MB image than to wait for 24MB from
>> > disk.
>> 
>> Linear reads from disk are fast. :) Linear reads from the SPI flash
>> are slower; and I think the decompression phase is quite a bit slower.
>> 
>> I'll investigate all of this further once I've played with GEOM_ULZMA.

LZMA compression optimized for fast decompression.
When I compress 3M kernel on DualCore @ 1.80GHz, I wait 3-5 sec.
When kernel decompressed by CFE loader on 240MHz MIPS CPU, it less than 2 sec. 

>> 
>> 
>> 
>> Adrian


-- 
Alexandr Rybalko <ray at dlink.ua> 
aka Alex RAY <ray at ddteam.net>