Date: Wed, 4 Jun 2008 07:58:31 +0900
To: paulus@samba.org
Cc: penberg@cs.helsinki.fi, fujita.tomonori@lab.ntt.co.jp,
       linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org,
       akpm@linux-foundation.org
Subject: Re: [PATCH -mm] clean up duplicated alloc/free_thread_info
From: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
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On Tue, 3 Jun 2008 16:42:25 +1000
Paul Mackerras <paulus@samba.org> wrote:

> Pekka Enberg writes:
> 
> > Yeah, I too have wondered why some architectures use kmalloc() whereas
> > others use the page allocator. Is THREAD_SIZE significantly smaller
> > than PAGE_SIZE for those?
> 
> 64-bit powerpc uses 16k kernel stacks and either 4k or 64k page size.
> If the page size is 64k then we don't want to allocate a whole page
> for a kernel stack.

On powerpc, the patch defines __HAVE_ARCH_THREAD_INFO_ALLOCATOR on the
THREAD_SHIFT < PAGE_SHIFT case so it doesn't change anything.
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