maria-developers team mailing list archive

[Marko Mäkelä <marko.makela@xxxxxxxxxxx>]

Looks OK to me. This can only slightly punish the very few people who are
upgrading from a buggy MySQL 5.6 or MariaDB 10.0 or 10.1 installation on a
big-endian machine (such as SPARC) into a newer version. And those users
could invoke innochecksum to rewrite the page checksums.

On Thu, Nov 23, 2017 at 12:57 PM, Sergey Vojtovich <svoj@xxxxxxxxxxx> wrote:

> revision-id: f28af027a0439d760c6d26eb67a932e97eb665d7
> (mariadb-10.3.2-66-gf28af02)
> parent(s): b2571e534f9eed873cc9b1ce5f48b109c1ee0fcc
> committer: Sergey Vojtovich
> timestamp: 2017-11-23 14:53:16 +0400
> message:
>
> Removed HW acceleration for big endian checksum
>
> Big endian checksum is needed to workaround 10+ years old bug, where
> checksum
> was calculated incorrectly on big endian hardware. We can still checksum
> such
> tablespaces using software implementation of CRC32.
>
> ---
>  storage/innobase/include/ut0crc32.h |  4 +-
>  storage/innobase/ut/ut0crc32.cc     | 89 +-----------------------------
> -------
>  2 files changed, 3 insertions(+), 90 deletions(-)
>
> diff --git a/storage/innobase/include/ut0crc32.h
> b/storage/innobase/include/ut0crc32.h
> index 509ac09..527a3e81 100644
> --- a/storage/innobase/include/ut0crc32.h
> +++ b/storage/innobase/include/ut0crc32.h
> @@ -47,9 +47,9 @@ typedef uint32_t      (*ut_crc32_func_t)(const byte*
> ptr, ulint len);
>  /** Pointer to CRC32 calculation function. */
>  extern ut_crc32_func_t ut_crc32;
>
> -/** Pointer to CRC32 calculation function, which uses big-endian byte
> order
> +/** CRC32 calculation function, which uses big-endian byte order
>  when converting byte strings to integers internally. */
> -extern ut_crc32_func_t ut_crc32_legacy_big_endian;
> +extern uint32_t ut_crc32_legacy_big_endian(const byte* buf, ulint len);
>
>  extern const char*     ut_crc32_implementation;
>
> diff --git a/storage/innobase/ut/ut0crc32.cc b/storage/innobase/ut/
> ut0crc32.cc
> index 6383e6d..36c52b7 100644
> --- a/storage/innobase/ut/ut0crc32.cc
> +++ b/storage/innobase/ut/ut0crc32.cc
> @@ -89,10 +89,6 @@ mysys/my_perf.c, contributed by Facebook under the
> following license.
>  /** Pointer to CRC32 calculation function. */
>  ut_crc32_func_t        ut_crc32;
>
> -/** Pointer to CRC32 calculation function, which uses big-endian byte
> order
> -when converting byte strings to integers internally. */
> -ut_crc32_func_t        ut_crc32_legacy_big_endian;
> -
>  /** Text description of CRC32 implementation */
>  const char*    ut_crc32_implementation;
>
> @@ -238,37 +234,6 @@ ut_crc32_64_hw(
>         *len -= 8;
>  }
>
> -/** Calculate CRC32 over 64-bit byte string using a hardware/CPU
> instruction.
> -The byte string is converted to a 64-bit integer using big endian byte
> order.
> -@param[in,out] crc     crc32 checksum so far when this function is called,
> -when the function ends it will contain the new checksum
> -@param[in,out] data    data to be checksummed, the pointer will be
> advanced
> -with 8 bytes
> -@param[in,out] len     remaining bytes, it will be decremented with 8 */
> -inline
> -void
> -ut_crc32_64_legacy_big_endian_hw(
> -       uint32_t*       crc,
> -       const byte**    data,
> -       ulint*          len)
> -{
> -       uint64_t        data_int = *reinterpret_cast<const
> uint64_t*>(*data);
> -
> -#ifndef WORDS_BIGENDIAN
> -       data_int = ut_crc32_swap_byteorder(data_int);
> -#else
> -       /* Currently we only support x86_64 (little endian) CPUs. In case
> -       some big endian CPU supports a CRC32 instruction, then maybe we
> will
> -       NOT need a byte order swap here. */
> -#error Dont know how to handle big endian CPUs
> -#endif /* WORDS_BIGENDIAN */
> -
> -       *crc = ut_crc32_64_low_hw(*crc, data_int);
> -
> -       *data += 8;
> -       *len -= 8;
> -}
> -
>  /** Calculates CRC32 using hardware/CPU instructions.
>  @param[in]     buf     data over which to calculate CRC32
>  @param[in]     len     data length
> @@ -355,56 +320,6 @@ ut_crc32_hw(
>
>         return(~crc);
>  }
> -
> -/** Calculates CRC32 using hardware/CPU instructions.
> -This function uses big endian byte ordering when converting byte sequence
> to
> -integers.
> -@param[in]     buf     data over which to calculate CRC32
> -@param[in]     len     data length
> -@return CRC-32C (polynomial 0x11EDC6F41) */
> -uint32_t
> -ut_crc32_legacy_big_endian_hw(
> -       const byte*     buf,
> -       ulint           len)
> -{
> -       uint32_t        crc = 0xFFFFFFFFU;
> -
> -       /* Calculate byte-by-byte up to an 8-byte aligned address. After
> -       this consume the input 8-bytes at a time. */
> -       while (len > 0 && (reinterpret_cast<uintptr_t>(buf) & 7) != 0) {
> -               ut_crc32_8_hw(&crc, &buf, &len);
> -       }
> -
> -       while (len >= 128) {
> -               /* This call is repeated 16 times. 16 * 8 = 128. */
> -               ut_crc32_64_legacy_big_endian_hw(&crc, &buf, &len);
> -               ut_crc32_64_legacy_big_endian_hw(&crc, &buf, &len);
> -               ut_crc32_64_legacy_big_endian_hw(&crc, &buf, &len);
> -               ut_crc32_64_legacy_big_endian_hw(&crc, &buf, &len);
> -               ut_crc32_64_legacy_big_endian_hw(&crc, &buf, &len);
> -               ut_crc32_64_legacy_big_endian_hw(&crc, &buf, &len);
> -               ut_crc32_64_legacy_big_endian_hw(&crc, &buf, &len);
> -               ut_crc32_64_legacy_big_endian_hw(&crc, &buf, &len);
> -               ut_crc32_64_legacy_big_endian_hw(&crc, &buf, &len);
> -               ut_crc32_64_legacy_big_endian_hw(&crc, &buf, &len);
> -               ut_crc32_64_legacy_big_endian_hw(&crc, &buf, &len);
> -               ut_crc32_64_legacy_big_endian_hw(&crc, &buf, &len);
> -               ut_crc32_64_legacy_big_endian_hw(&crc, &buf, &len);
> -               ut_crc32_64_legacy_big_endian_hw(&crc, &buf, &len);
> -               ut_crc32_64_legacy_big_endian_hw(&crc, &buf, &len);
> -               ut_crc32_64_legacy_big_endian_hw(&crc, &buf, &len);
> -       }
> -
> -       while (len >= 8) {
> -               ut_crc32_64_legacy_big_endian_hw(&crc, &buf, &len);
> -       }
> -
> -       while (len > 0) {
> -               ut_crc32_8_hw(&crc, &buf, &len);
> -       }
> -
> -       return(~crc);
> -}
>  #endif /* defined(__GNUC__) && defined(__x86_64__) */
>
>  /* CRC32 software implementation. */
> @@ -600,7 +515,7 @@ integers.
>  @param[in]     len     data length
>  @return CRC-32C (polynomial 0x11EDC6F41) */
>  uint32_t
> -ut_crc32_legacy_big_endian_sw(
> +ut_crc32_legacy_big_endian(
>         const byte*     buf,
>         ulint           len)
>  {
> @@ -654,7 +569,6 @@ ut_crc32_init()
>  {
>         ut_crc32_slice8_table_init();
>         ut_crc32 = ut_crc32_sw;
> -       ut_crc32_legacy_big_endian = ut_crc32_legacy_big_endian_sw;
>         ut_crc32_implementation = "Using generic crc32 instructions";
>
>  #if defined(__GNUC__) && defined(__x86_64__)
> @@ -687,7 +601,6 @@ ut_crc32_init()
>
>         if (features_ecx & 1 << 20) {
>                 ut_crc32 = ut_crc32_hw;
> -               ut_crc32_legacy_big_endian = ut_crc32_legacy_big_endian_hw;
>                 ut_crc32_implementation = "Using SSE2 crc32 instructions";
>         }
>
> _______________________________________________
> commits mailing list
> commits@xxxxxxxxxxx
> https://lists.askmonty.org/cgi-bin/mailman/listinfo/commits




-- 
Marko Mäkelä, Lead Developer InnoDB
MariaDB Corporation

DON’T MISS

M|18

MariaDB User Conference

February 26 - 27, 2018

New York City

https://m18.mariadb.com/