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Update LZO compression

PATCH Seth Jennings 2 participants 3 messages Oct 15, 2012 – Oct 16, 2012

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Quoted 8 lines

As requested by akpm I am sending my "lzo-update" branch at

git://github.com/markus-oberhumer/linux.git lzo-update

to lkml as a patch series created by "git format-patch -M v3.5..lzo-update".

You can also browse the branch at

Quoted 7 lines

https://github.com/markus-oberhumer/linux/compare/lzo-update

and review the three patches at

https://github.com/markus-oberhumer/linux/commit/7c979cebc0f93dc692b734c12665a6824d219c20
https://github.com/markus-oberhumer/linux/commit/10f6781c8591fe5fe4c8c733131915e5ae057826
https://github.com/markus-oberhumer/linux/commit/5f702781f158cb59075cfa97e5c21f52275057f1

As this relates to my work on zcache, I just tested these patches on PPC64 and they cause the LZO crypto module to fail its self-test:

[    0.521137] alg: comp: Compression test 1 failed for lzo-generic: output len = 62

I built the exact same kernel for x86_64 and all is fine. I suspect an endianness related bug, but I haven't looked at the code that closely yet.

Any ideas? I'd be happy to test any potential fixes.

Seth

#1 lore raw
Quoted 19 lines · Seth Jennings
Quoted 8 lines

As requested by akpm I am sending my "lzo-update" branch at

git://github.com/markus-oberhumer/linux.git lzo-update

to lkml as a patch series created by "git format-patch -M v3.5..lzo-update".

You can also browse the branch at

Quoted 7 lines

https://github.com/markus-oberhumer/linux/compare/lzo-update

and review the three patches at

https://github.com/markus-oberhumer/linux/commit/7c979cebc0f93dc692b734c12665a6824d219c20
https://github.com/markus-oberhumer/linux/commit/10f6781c8591fe5fe4c8c733131915e5ae057826
https://github.com/markus-oberhumer/linux/commit/5f702781f158cb59075cfa97e5c21f52275057f1

As this relates to my work on zcache, I just tested these patches on PPC64 and they cause the LZO crypto module to fail its self-test:

Quoted 6 lines
[    0.521137] alg: comp: Compression test 1 failed for lzo-generic: output len = 62

I built the exact same kernel for x86_64 and all is fine. I suspect an endianness related bug, but I haven't looked at the code that closely yet.

Any ideas? I'd be happy to test any potential fixes.

The crypto LZO test vectors had to be updated - this should land in linux-next soon (or you can just pull from my branch).

BTW, this cannot have worked on x86_64 (or any other arch), so you probably tested the wrong kernel.

Cheers,
Markus

Quoted 1 line

Seth

Signature · 1 line
Markus Oberhumer, <[email protected]>, http://www.oberhumer.com/
#2 lore raw
Quoted 2 lines · Markus F.X.J. Oberhumer

The crypto LZO test vectors had to be updated - this should land in linux-next soon (or you can just pull from my branch).

Thanks, I pulled from your branch and now it works fine.

I noticed that you made the test vectors longer. Any particular reason? Is there a new minimum length now or something?

I guess I'm not understanding why a change to the test vectors was needed.

Seth