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Date:   Wed, 21 Mar 2018 15:41:28 +0900
From:   Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
To:     Maninder Singh <maninder1.s@samsung.com>
Cc:     herbert@gondor.apana.org.au, davem@davemloft.net,
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        pankaj.m@samsung.com, a.sahrawat@samsung.com, v.narang@samsung.com
Subject: Re: [PATCH 0/1] cover-letter/lz4: Implement lz4 with dynamic offset
 length.
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On (03/21/18 10:10), Maninder Singh wrote:
> (Added cover letter to avoid much text in patch description)
> 
> LZ4 specification defines 2 byte offset length for 64 KB data.
> But in case of ZRAM we compress data per page and in most of
> architecture PAGE_SIZE is 4KB. So we can decide offset length based
> on actual offset value. For this we can reserve 1 bit to decide offset
> length (1 byte or 2 byte). 2 byte required only if ofsset is greater than 127,
> else 1 byte is enough.

So what happens if I compress the data on a system with no dyn
offset and then send it over the network to a machine which has
dyn offset? Or, say, I have a USB stick with a compression enabled
FS, store files on a dyn offset enabled PC and then mount that USB
stick on a machine with no dyn offset support. And vice versa.

	-ss