]> git.baikalelectronics.ru Git - kernel.git/commit
lib: Prepare zstd for preboot environment, improve performance
authorNick Terrell <terrelln@fb.com>
Thu, 30 Jul 2020 19:08:34 +0000 (12:08 -0700)
committerIngo Molnar <mingo@kernel.org>
Fri, 31 Jul 2020 09:49:07 +0000 (11:49 +0200)
commitd9245a43a9c41d2063e4750e3bbbd79c9a936f5e
treefb92c50c613e17641519af0d27a5a098707dc4a9
parentcd194de09f766ecaa52d957318a77257f18d3584
lib: Prepare zstd for preboot environment, improve performance

These changes are necessary to get the build to work in the preboot
environment, and to get reasonable performance:

- Remove a double definition of the CHECK_F macro when the zstd
  library is amalgamated.

- Switch ZSTD_copy8() to __builtin_memcpy(), because in the preboot
  environment on x86 gcc can't inline `memcpy()` otherwise.

- Limit the gcc hack in ZSTD_wildcopy() to the broken gcc version. See
  https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81388.

ZSTD_copy8() and ZSTD_wildcopy() are in the core of the zstd hot loop.
So outlining these calls to memcpy(), and having an extra branch are very
detrimental to performance.

Signed-off-by: Nick Terrell <terrelln@fb.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20200730190841.2071656-2-nickrterrell@gmail.com
lib/zstd/fse_decompress.c
lib/zstd/zstd_internal.h