Re: [PATCH v6 2/8] crypto: add driver-side scomp interface

On Tue, Jun 28, 2016 at 08:41:42AM +0100, Giovanni Cabiddu wrote:

Are you suggesting a different cache of scratch buffers for every
algorithm implementation or a shared cache shared across all legacy
scomp algorithms?

One that's shared for every scomp algorithm.

Would it be ok 128K instead?
We are proposing to use the acomp API from BTRFS. Limiting the size
of the source and destination buffers to 64K would not work since
BTRFS usually compresses 128KB. 
Here is the RFC sent by Weigang to the BTFS list:
http://www.spinics.net/lists/linux-btrfs/msg56648.html

While I don't see any big differences between 64K and 128K, I have
noticed that btrfs is already doing partial decompression on a
page-by-page basis, which is the most optimal setup.

So whatever we do for this conversion we should make sure that
btrfs does not regress into using vmalloc.

Cheers,
-- 
Email: Herbert Xu [off-list ref]
Home Page: http://gondor.apana.org.au/~herbert/
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