Re: [PATCH 1/3]: compressed RAM block device

[Nick Piggin <nickpiggin@yahoo.com.au>]

On Tuesday 17 March 2009 22:36:46 Nitin Gupta wrote:
>   drivers/block/Kconfig     |   22 +
>   drivers/block/Makefile    |    1 +
>   drivers/block/compcache.c |  995
> +++++++++++++++++++++++++++++++++++++++++++++ drivers/block/compcache.h | 
> 160 ++++++++
>   4 files changed, 1178 insertions(+), 0 deletions(-)
>
> Creates RAM based block device (ramzswap0) which can be used as swap
> device. Pages swapped to this are compressed and stored in memory itself.
>
> The module is called compcache.ko. It depends on:
>   - xvmalloc.ko: memory allocator
>   - lzo_compress.ko
>   - lzo_decompress.ko
>
> See Documentation/blockdev/compcache.txt for usage details.
>
> Project home: http://code.google.com/p/compcache/

I wonder how hard it would be to make the compression code
use an arbitrary file or device for the storage backend rather
than make a new block device? Then you could make a new ram
block device that can swap its pages out (or even extend brd.c
with that functionality, or use loop on tmpfs etc).