Re: Proposal for Updating CRC32C with AVX-512 Algorithm. - Mailing list pgsql-hackers

On 2024-Jun-12, Amonson, Paul D wrote:

> +/*-------------------------------------------------------------------------
> + *
> + * pg_crc32c_avx512.c
> + *      Compute CRC-32C checksum using Intel AVX-512 instructions.
> + *
> + * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
> + * Portions Copyright (c) 1994, Regents of the University of California
> + * Portions Copyright (c) 2024, Intel(r) Corporation
> + *
> + * IDENTIFICATION
> + *      src/port/pg_crc32c_avx512.c
> + *
> + *-------------------------------------------------------------------------
> + */

Hmm, I wonder if the "(c) 2024 Intel" line is going to bring us trouble.
(I bet it's not really necessary anyway.)

> +/*******************************************************************
> + * pg_crc32c_avx512(): compute the crc32c of the buffer, where the
> + * buffer length must be at least 256, and a multiple of 64. Based
> + * on:
> + *
> + * "Fast CRC Computation for Generic Polynomials Using PCLMULQDQ
> + * Instruction"
> + *  V. Gopal, E. Ozturk, et al., 2009,
> + *  https://www.researchgate.net/publication/263424619_Fast_CRC_computation#full-text
> + *
> + * This Function:
> + * Copyright 2017 The Chromium Authors
> + * Copyright (c) 2024, Intel(r) Corporation
> + *
> + * Use of this source code is governed by a BSD-style license that can be
> + * found in the Chromium source repository LICENSE file.
> + * https://chromium.googlesource.com/chromium/src/+/refs/heads/main/LICENSE
> + */

And this bit doesn't look good.  The LICENSE file says:

> // Redistribution and use in source and binary forms, with or without
> // modification, are permitted provided that the following conditions are
> // met:
> //
> //    * Redistributions of source code must retain the above copyright
> // notice, this list of conditions and the following disclaimer.
> //    * Redistributions in binary form must reproduce the above
> // copyright notice, this list of conditions and the following disclaimer
> // in the documentation and/or other materials provided with the
> // distribution.
> //    * Neither the name of Google LLC nor the names of its
> // contributors may be used to endorse or promote products derived from
> // this software without specific prior written permission.

The second clause essentially says we would have to add a page to our
"documentation and/or other materials" with the contents of the license
file.

There's good reasons for UCB to have stopped using the old BSD license,
but apparently Google (or more precisely the Chromium authors) didn't
get the memo.


Our fork distributors spent a lot of time scouring out source cleaning
up copyrights, a decade ago or two.  I bet they won't be happy to see
this sort of thing crop up now.

-- 
Álvaro Herrera        Breisgau, Deutschland  —  https://www.EnterpriseDB.com/
"No nos atrevemos a muchas cosas porque son difíciles,
pero son difíciles porque no nos atrevemos a hacerlas" (Séneca)