Re: [BUG] lib: zram lz4 compression/decompression still broken on big endian

From	Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Newsgroups	linux.kernel
Subject	Re: [BUG] lib: zram lz4 compression/decompression still broken on big endian
Date	2016-04-07 15:10 +0200
Message-ID	<rlhR7-4fL-1@gated-at.bofh.it> (permalink)
References	(2 earlier) <rkBIf-6yB-25@gated-at.bofh.it> <rkOm5-7DR-5@gated-at.bofh.it> <rkSg1-1O6-1@gated-at.bofh.it> <rkUBc-3Dr-13@gated-at.bofh.it> <rlho6-3Mb-23@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On (04/07/16 13:33), Rui Salvaterra wrote:
[..]
> Hi again, Sergey

Hello,

> Thanks for the patch, I'll test it as soon as possible. I agree with
> your second option, usually one selects lz4 when (especially
> decompression) speed is paramount, so it needs all the help it can
> get.

thanks!

> Speaking of fishy, the 64-bit detection code also looks suspiciously
> bogus. Some of the identifiers don't even exist anywhere in the kernel
> (__ppc64__, por example, after grepping all .c and .h files).
> Shouldn't we instead check for CONFIG_64BIT or BITS_PER_LONG == 64?

definitely a good question. personally, I'd prefer to test for
CONFIG_64BIT only, looking at this hairy

  /* Detects 64 bits mode */
  #if (defined(__x86_64__) || defined(__x86_64) || defined(__amd64__) \
         || defined(__ppc64__) || defined(__LP64__))

and remove/rewrite a bunch of other stuff. but the thing with cleanups
is that they don't fix anything, while potentially can introduce bugs.
it's more risky to touch the stable code. /* well, removing those 'ghost'
identifiers is sort of OK to me */. but that's just my opinion, I'll
leave it to you and Greg.

	-ss

Thread

[BUG] lib: zram lz4 compression/decompression still broken on big endian Rui Salvaterra <rsalvaterra@gmail.com> - 2016-04-05 16:10 +0200
  Re: [BUG] lib: zram lz4 compression/decompression still broken on  big endian Greg KH <gregkh@linuxfoundation.org> - 2016-04-05 17:40 +0200
    Re: [BUG] lib: zram lz4 compression/decompression still broken on big endian Rui Salvaterra <rsalvaterra@gmail.com> - 2016-04-05 18:10 +0200
      Re: [BUG] lib: zram lz4 compression/decompression still broken on  big endian Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> - 2016-04-06 07:40 +0200
        Re: [BUG] lib: zram lz4 compression/decompression still broken on big endian Rui Salvaterra <rsalvaterra@gmail.com> - 2016-04-06 11:50 +0200
          Re: [BUG] lib: zram lz4 compression/decompression still broken on  big endian Sergey Senozhatsky <sergey.senozhatsky@gmail.com> - 2016-04-06 14:20 +0200
            Re: [BUG] lib: zram lz4 compression/decompression still broken on big endian Rui Salvaterra <rsalvaterra@gmail.com> - 2016-04-07 14:40 +0200
              Re: [BUG] lib: zram lz4 compression/decompression still broken on  big endian Sergey Senozhatsky <sergey.senozhatsky@gmail.com> - 2016-04-07 15:10 +0200
                Re: [BUG] lib: zram lz4 compression/decompression still broken on big endian Rui Salvaterra <rsalvaterra@gmail.com> - 2016-04-08 17:00 +0200

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