On Wed, Jun 01, 2011 at 10:32:55AM +0800, Pei Lin wrote:

As the newbie, look at here, suddenly one thought rush in my brain.
After twenty years development, the kernel became bigger and bigger.
The cost time for building the kernel becomes much more.

Sure, more code that does more and more complex compilers means more
time to build the code.

If someone writes one new feature in kernel core, he maybe wants to
load the component directly into running kernel instead of rebuild the
kernel and reboot it.
Could the kernel support all components reloadable dynamically in core
as scheduler, memory management etc?

We support modules already, just not for some core things, so you can do
this today.

Now the driver subsystem is modularity, could kernel make everything
modularity and all things be hotplugged?

Everything that can be physically hotplugged can be with Linux (i.e.
hardware).  We don't want to have different schedulers, but we do have
different i/o schedulers already that can be changed dynamically.  The
mm core does not make any sense to be a module though.

Hope this helps,

greg k-h