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

[Nitin Gupta <ngupta@vflare.org>]

Pavel Machek wrote:
> On Tue 2009-03-17 17:06:46, 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/
> 
> 
> Compcache is really bad name for this. zramdisk? gzrd?
> 
It was named compcache according to its original goal:
compressed caching for anonymous _and_ filesystem caches. This ram block
device is for handling anonymous memory only. Anyway, actual block device
is called ramzswap which you might like more :)

> Is the block device useful for general filesystem storage?
> 
No. It can only handle page aligned I/O. But it shouldn't be too hard
to make it generic compressed ram disk with physical backing device support.
But unfortunately I do not have bandwidth to do this myself.

Thanks,
Nitin