Message-ID: <4A67CEB7.2080505@zytor.com>
Date: Wed, 22 Jul 2009 19:45:11 -0700
From: "H. Peter Anvin" <hpa@zytor.com>
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To: Dave Hansen <dave@linux.vnet.ibm.com>
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Subject: Re: [RFCv2][PATCH] flexible array implementation
References: <20090721220017.60A219D3@kernel>
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On 07/21/2009 03:00 PM, Dave Hansen wrote:
> 
> Here's an alternative.  I think it's what Andrew was
> suggesting  here:
> 
> 	http://lkml.org/lkml/2009/7/2/518 
> 
> I call it a flexible array.  It does all of its work in
> PAGE_SIZE bits, so never does an order>0 allocation.
> The base level has PAGE_SIZE-2*sizeof(int) bytes of
> storage for pointers to the second level.  So, with a
> 32-bit arch, you get about 4MB (4183112 bytes) of total
> storage when the objects pack nicely into a page.  It
> is half that on 64-bit because the pointers are twice
> the size.
> 

I'm wondering if there is any use case which would require scaling below
the PAGE_SIZE level... in which case it would be nice for it to
gracefully decay to a single kmalloc allocation + some metadata.

	-hpa

-- 
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel.  I don't speak on their behalf.

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