Message-ID: <4BD06B31.9050306@redhat.com>
Date: Thu, 22 Apr 2010 18:28:49 +0300
From: Avi Kivity <avi@redhat.com>
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To: Dan Magenheimer <dan.magenheimer@oracle.com>
CC: linux-kernel@vger.kernel.org, linux-mm@kvack.org, jeremy@goop.org,
       hugh.dickins@tiscali.co.uk, ngupta@vflare.org, JBeulich@novell.com,
       chris.mason@oracle.com, kurt.hackel@oracle.com,
       dave.mccracken@oracle.com, npiggin@suse.de, akpm@linux-foundation.org,
       riel@redhat.com
Subject: Re: Frontswap [PATCH 0/4] (was Transcendent Memory): overview
References: <20100422134249.GA2963@ca-server1.us.oracle.com>
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On 04/22/2010 04:42 PM, Dan Magenheimer wrote:
> Frontswap is so named because it can be thought of as the opposite of
> a "backing" store for a swap device.  The storage is assumed to be
> a synchronous concurrency-safe page-oriented pseudo-RAM device (such as
> Xen's Transcendent Memory, aka "tmem", or in-kernel compressed memory,
> aka "zmem", or other RAM-like devices) which is not directly accessible
> or addressable by the kernel and is of unknown and possibly time-varying
> size.  This pseudo-RAM device links itself to frontswap by setting the
> frontswap_ops pointer appropriately and the functions it provides must
> conform to certain policies as follows:
>    

How baked in is the synchronous requirement?  Memory, for example, can 
be asynchronous if it is copied by a dma engine, and since there are 
hardware encryption engines, there may be hardware compression engines 
in the future.


-- 
error compiling committee.c: too many arguments to function

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