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Date: Fri, 7 Feb 2014 10:11:39 -0800
From: Andi Kleen <ak@linux.intel.com>
To: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
        Peter Anvin <hpa@zytor.com>, Ingo Molnar <mingo@redhat.com>,
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        Ning Qu <quning@google.com>, Dave Hansen <dave.hansen@linux.intel.com>,
        Matthew Wilcox <willy@linux.intel.com>
Subject: Re: [RFC, PATCH] mm: map few pages around fault address if they are
 in page cache
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> > There are some extreme cases where workloads could use a lot more memory
> > than before, if they access their memory sparsely in the right pattern.
> 
> Have you noticied that we don't actually allocate any memory: only reuse
> what's already there. Sure, it will increase VmSize, but do we care?

Good point. With that probably readahead is overkill, agree.

We would need it though if we ever do it for anonymous.

-Andi

-- 
ak@linux.intel.com -- Speaking for myself only