Document that AVX512F has been disabled for GCC builds [1] and document its potential implications on release notes, known issue section. [1] Commit 8d07c82b239f ("mk: disable gcc AVX512F support") Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com> --- doc/guides/rel_notes/release_18_11.rst | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/doc/guides/rel_notes/release_18_11.rst b/doc/guides/rel_notes/release_18_11.rst index 32ff0e5c0..1116aff57 100644 --- a/doc/guides/rel_notes/release_18_11.rst +++ b/doc/guides/rel_notes/release_18_11.rst @@ -567,6 +567,17 @@ Known Issues * IBM Power8 is not supported by this release of DPDK. IBM Power9 is supported. +* ``AVX-512`` support has been disabled for ``GCC`` builds [1] because of a crash [2]. + This can affect ``native`` machine type build targets on the platforms that support + ``AVX512F`` like ``Intel Skylake`` processors, and can cause a possible performance drop. + The immediate workaround is to use ``clang`` compiler on these platforms. + Issue has been identified as a GCC defect and reported to GCC community [3]. Further + actions will be taken based on the GCC defect result. + + [1]: Commit 8d07c82b239f ("mk: disable gcc AVX512F support") + [2]: https://bugs.dpdk.org/show_bug.cgi?id=97 + [3]: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88096 + Tested Platforms ---------------- -- 2.17.2
> -----Original Message-----
> From: Yigit, Ferruh
> Sent: Tuesday, November 20, 2018 12:51 PM
> To: Mcnamara, John <john.mcnamara@intel.com>; Kovacevic, Marko
> <marko.kovacevic@intel.com>
> Cc: dev@dpdk.org; Yigit, Ferruh <ferruh.yigit@intel.com>; Richardson,
> Bruce <bruce.richardson@intel.com>; Ananyev, Konstantin
> <konstantin.ananyev@intel.com>
> Subject: [PATCH] doc: announce disabling GCC AVX512F as known issue
>
> Document that AVX512F has been disabled for GCC builds [1] and document
> its potential implications on release notes, known issue section.
>
Acked-by: John McNamara <john.mcnamara@intel.com>
22/11/2018 19:00, Mcnamara, John:
> From: Yigit, Ferruh
> >
> > Document that AVX512F has been disabled for GCC builds [1] and document
> > its potential implications on release notes, known issue section.
> >
>
> Acked-by: John McNamara <john.mcnamara@intel.com>
Applied, thanks