Re: [PATCH] move task_struct allocation to arch

[David Howells <dhowells@redhat.com>]

Jeff Garzik <jgarzik@mandrakesoft.com> wrote:
> David Howells wrote:
> > > Is this the first in a multi-step patch series, or something like that?
> > 
> > What makes you ask that?
> 
> Because your patch just flat out duplicates code line for line into two
> arches.

What I do to it next depends on the feedback I get back.

> I am wondering where you want to go with this, short term and long
> term.  Is the implementation of this on other arches gonna look the same
> -- just line for line copy of code?  With maybe ia64 as the lone
> exception?

Ask Linus, he asked for the task_struct/thread_info split. Various people have
complained about the two things being allocated separately (maintainers for
m68k and ia64 archs certainly, and if I remember rightly, x86_64 as well,
though I don't appear to have saved the message for that). However, DaveM
(sparc64) appears to really be in favour of it.

In any case, this is just a corollary to my main aim of getting task ornaments
included in the kernel. The userspace resumption notification was the true
prerequisite, to support which I adjusted entry.S to make sure it didn't cost
any extra clock cycles. This led to Linus requesting that everything that
entry.S needs to access be separated out into another structure (so that
entry.S never accesses task_struct).

David