linux-kernel - Re: [GIT PULL] Update LZO compression

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <502D2471.407@pobox.com>
Date:	Thu, 16 Aug 2012 12:48:49 -0400
From:	Jeff Garzik <jgarzik@...ox.com>
To:	Andi Kleen <andi@...stfloor.org>
CC:	"Markus F.X.J. Oberhumer" <markus@...rhumer.com>,
	Johannes Stezenbach <js@...21.net>,
	linux-kernel@...r.kernel.org, chris.mason@...ionio.com,
	linux-btrfs@...r.kernel.org, Nitin Gupta <ngupta@...are.org>,
	Richard Purdie <rpurdie@...nedhand.com>,
	richard -rw- weinberger <richard.weinberger@...il.com>,
	linux-arm-kernel@...ts.infradead.org
Subject: Re: [GIT PULL] Update LZO compression

On 08/16/2012 12:20 PM, Andi Kleen wrote:
>> If you think a little bit, I bet you could come up with a solution that
>> operates at cacheline-aligned granularity, something that would be _even
>> faster_ than simply fixing the code to do aligned accesses.
>
> Cache aligned compression is unlikely to compress anything at all.
> Compression algorithms are usually by definition unaligned.

Sure it's a bitstream, but that does not imply the impossibility of 
reading data in in an word-aligned manner.

Maybe cache-aligned is ambitious, because of resultant code bloat, but 
machine-int-aligned is doable and reasonable.

	Jeff




--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/