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Date: Tue, 8 Sep 2009 21:15:39 -0700 (PDT)
From: David Rientjes <rientjes@google.com>
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To: Li Zefan <lizf@cn.fujitsu.com>
cc: Dave Hansen <dave@linux.vnet.ibm.com>,
       Andrew Morton <akpm@linux-foundation.org>, linux-kernel@vger.kernel.org
Subject: Re: [patch 3/4 -mm] flex_array: poison free elements
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On Wed, 9 Sep 2009, Li Zefan wrote:

> > Gack, ftrace_page would probably be better off simply using the flex list 
> > implementation I suggested which constructs a list from page->lru since it 
> > doesn't appear to require indexing into the array, it simply requires an 
> > iteration in all cases (or am I wrong?).  Flex lists could easily be made 
> > to support seqfiles.
> > 
> 
> Right, iteration is needed but indexing is not. I thought
> about flex list too, flex array has some limitations which
> make it hard to find a real user.
> 

I agree, the cgroup pidarray could be converted into a flex list 
implementation as well as ftrace_page, it appears.  All the metadata can 
be stored by overloading struct page and linking them in a dynamically 
expanding list on page->lru.

I'm thinking Andrew will want to see some user of this library in 2.6.32 
that cannot be served by a flex list type of implementation if we're to 
keep it merged in the kernel.