Re: [PATCH] Kexec: Remove order

[ebiederm@xmission.com (Eric W. Biederman)]

Magnus Damm <magnus@valinux.co.jp> writes:

> Kexec: Remove order
>
> This patch replaces kexec n-order allocation code with 0-order only.
>
> Almost all kexec allocations are 0-order pages already, with the exception of 
> some x86_64 specific code that requests two physically contiguous pages. 
>
> These two physically contiguous pages are easily replaced with two separate
> pages. The second page is kept in an architecture specific pointer that is
> added to struct kimage.
>
> Using 0-order allocations only greatly simplifies kexec porting work to
> the Xen hypervisor.

NACK.

It is a big intrusive patch that makes it impossible to
port to some architectures, and it obscures what you
are really trying to do which is fix x86_64.

Feel free to fix x86_64, to use only page sized allocates.

Until I see a reasonable argument that none of the architectures
currently supported by the linux kernel would need a multi order
allocation for a kexec port am I interested in removing support.

As I recall the alpha had an architectural need for a 32KB
allocation or something like that.

Eric