I hava an idea to Make OpenEmbedded Run Faster

[杨同峰 <yangtf@envision.com.cn>]

EveryOne: 
      By two week  of using OE , I hava notice that task was topology
sort to a queue .and  Run Task One By One. 
draw on the experience of Design of CPU . we can make a multiply thread
run of it ! 

      I notice that the biggest bottleneck of OE is do_fetch . then we
can use a mutiply thread downloader instead of wget 
      And about task schedule ,use method like this:

     bb_No1 do_fetch   do_patch do_configure do_build do_install
     bb_No2                  do_fetch  do_patch       do_configure
do_build do_install
     bb_No3                                 do_fetch      do_patch
do_configure do_build do_install
     bb_No4
do_fetch  .......

     Idea 1 :    focus on download one file one time ,and make it more
fast use mutiply thread downloader 
     Idea 2 :    make 0ther task of bb files  to run  asynchronously 
     Idea 3 :   deal with task  topology more carefully to make sure
that  the bb file that was dependend was finish before
                    this one start to do_patch (Notice : not before
do_fetch ) 
     Idea 4 :   If topology can't make sure Idea 3 ,we must tell OE how
and when  to wait 

     If the Idea can come true ,The speed can go 3 times faster then
now 

Tongfeng Yang
2007-8-27