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Subject: Re: [PATCH 0/1] cover-letter/lz4: Implement lz4 with dynamic offset
 length.
Reply-To: maninder1.s@samsung.com
From:   Maninder Singh <maninder1.s@samsung.com>
To:     "sergey.senozhatsky.work@gmail.com" 
        <sergey.senozhatsky.work@gmail.com>
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In-Reply-To: <20180321064128.GA468@jagdpanzerIV>
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Date:   Mon, 02 Apr 2018 11:33:54 +0530
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=C2=A0Hello,=0D=0A=0D=0A>>=20(Added=20cover=20letter=20to=20avoid=20much=20=
text=20in=20patch=20description)=0D=0A>>=20=0D=0A>>=20LZ4=20specification=
=20defines=202=20byte=20offset=20length=20for=2064=20KB=20data.=0D=0A>>=20B=
ut=20in=20case=20of=20ZRAM=20we=20compress=20data=20per=20page=20and=20in=
=20most=20of=0D=0A>>=20architecture=20PAGE_SIZE=20is=204KB.=20So=20we=20can=
=20decide=20offset=20length=20based=0D=0A>>=20on=20actual=20offset=20value.=
=20For=20this=20we=20can=20reserve=201=20bit=20to=20decide=20offset=0D=0A>>=
=20length=20(1=20byte=20or=202=20byte).=202=20byte=20required=20only=20if=
=20ofsset=20is=20greater=20than=20127,=0D=0A>>=20else=201=20byte=20is=20eno=
ugh.=0D=0A>=20=0D=0A>So=20what=20happens=20if=20I=20compress=20the=20data=
=20on=20a=20system=20with=20no=20dyn=0D=0A>offset=20and=20then=20send=20it=
=20over=20the=20network=20to=20a=20machine=20which=20has=0D=0A>dyn=20offset=
?=20Or,=20say,=20I=20have=20a=20USB=20stick=20with=20a=20compression=20enab=
led=0D=0A>FS,=20store=20files=20on=20a=20dyn=20offset=20enabled=20PC=20and=
=20then=20mount=20that=20USB=0D=0A>stick=20on=20a=20machine=20with=20no=20d=
yn=20offset=20support.=20And=20vice=20versa.=0D=0A=0D=0A=0D=0Alz4_dyn=20is=
=20not=20an=20extension=20of=20LZ4=20so=20there=20is=20no=20backward=20comp=
atibility.=0D=0AConsider=20this=20as=20a=20different=20algorithm=20adapted=
=20from=20LZ4=20for=20better=20compression=20ratio.=0D=0A=0D=0AThanks=0D=0A=
Maninder=20Singh