Q: vailable memory when initrd exists?

["Y Yang" <yyang702@gmail.com>]

In "arch/mips/kernel/setup.c", it appears that the "free memory" pool
is the memory area after kernel code and initrd if configured. Since
the location of "initrd" is set by "rd_start", it is possible that
there will be "memory hole" between the kernel and "initrd". It is my
understanding that the memory area up to the "free memory" pool will
not be available, even after "initrd" is freed later in the boot
process. I am curious as why it is necessary to do it this way? What
if we treat the whole area after the kernel code as the "free memory"
pool? This shouldn't affect "initrd", as the memory used by "initrd"
is reserved.

I looked at both older 2.6.14 and the latest kernel code. That part of
the logic seems largely unchanged. I suspect I must have missed
something.

Thanks for your help in advance.

Regards,

Steve.