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Date: Thu, 11 Dec 2008 18:47:53 -0800
From: Andrew Morton <akpm@linux-foundation.org>
To: Nick Piggin <nickpiggin@yahoo.com.au>
Subject: Re: [PATCH][v2] fork_init: fix division by zero
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On Fri, 12 Dec 2008 12:31:33 +1000 Nick Piggin <nickpiggin@yahoo.com.au> wrote:

> On Friday 12 December 2008 07:43, Andrew Morton wrote:
> > On Thu, 11 Dec 2008 20:28:00 +0000
> 
> > >  Do they actually cross the page boundaries?
> >
> > Some flavours of slab have at times done an order-1 allocation for
> > objects which would fit into an order-0 page (etc) if it looks like
> > that will be beneficial from a packing POV.  I'm unsure whether that
> > still happens - I tried to get it stamped out for reliability reasons.
> 
> Hmph, SLUB uses order-3 allocations for 832 byte sized objects
> by default here (mm struct).

That sucks, but at least it's <= PAGE_ALLOC_COSTLY_ORDER.

It's fortunate that everyone has more than 128GB of memory.