doc: announce disabling GCC AVX512F as known issue
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Commit Message
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(+)
Comments
> -----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
@@ -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
----------------