[dpdk-dev] config: make AVX and AVX512 configurable
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Commit Message
Making AVX and AVX512 configurable is useful for performance and power
testing.
The similar kernel patch at https://patchwork.kernel.org/patch/9618883/.
Signed-off-by: Zhihong Wang <zhihong.wang@intel.com>
---
config/common_base | 6 ++++++
mk/rte.cpuflags.mk | 6 ++++++
2 files changed, 12 insertions(+)
Comments
27/04/2017 18:34, Zhihong Wang:
> Making AVX and AVX512 configurable is useful for performance and power
> testing.
>
> The similar kernel patch at https://patchwork.kernel.org/patch/9618883/.
[...]
> +#
> +# Recognize/ignore the AVX/AVX512 CPU flags for performance/power testing
> +#
> +CONFIG_RTE_ENABLE_AVX=y
> +CONFIG_RTE_ENABLE_AVX512=n
It is disabling AVX512 in default configuration.
Please explain this behaviour change.
> -----Original Message-----
> From: Thomas Monjalon [mailto:thomas@monjalon.net]
> Sent: Thursday, April 27, 2017 5:08 PM
> To: Wang, Zhihong <zhihong.wang@intel.com>; Richardson, Bruce
> <bruce.richardson@intel.com>
> Cc: dev@dpdk.org; yuanhan.liu@linux.intel.com
> Subject: Re: [dpdk-dev] [PATCH] config: make AVX and AVX512 configurable
>
> 27/04/2017 18:34, Zhihong Wang:
> > Making AVX and AVX512 configurable is useful for performance and power
> > testing.
> >
> > The similar kernel patch at https://patchwork.kernel.org/patch/9618883/.
> [...]
> > +#
> > +# Recognize/ignore the AVX/AVX512 CPU flags for performance/power
> testing
> > +#
> > +CONFIG_RTE_ENABLE_AVX=y
> > +CONFIG_RTE_ENABLE_AVX512=n
>
> It is disabling AVX512 in default configuration.
> Please explain this behaviour change.
Though AVX512 rte_memcpy has been in DPDK for quite a while it's still
unproven in hardware with rich use cases. Mark it as experimental for
now, user can enable it for their own testing.
Will enable it with enough field tests and possible optimization.
Should I add the explanation in commit log, or comments in the source,
or both?
27/04/2017 11:18, Wang, Zhihong:
> From: Thomas Monjalon [mailto:thomas@monjalon.net]
> > 27/04/2017 18:34, Zhihong Wang:
> > > Making AVX and AVX512 configurable is useful for performance and power
> > > testing.
> > >
> > > The similar kernel patch at https://patchwork.kernel.org/patch/9618883/.
> > [...]
> > > +#
> > > +# Recognize/ignore the AVX/AVX512 CPU flags for performance/power
> > testing
> > > +#
> > > +CONFIG_RTE_ENABLE_AVX=y
> > > +CONFIG_RTE_ENABLE_AVX512=n
> >
> > It is disabling AVX512 in default configuration.
> > Please explain this behaviour change.
>
> Though AVX512 rte_memcpy has been in DPDK for quite a while it's still
> unproven in hardware with rich use cases. Mark it as experimental for
> now, user can enable it for their own testing.
>
> Will enable it with enough field tests and possible optimization.
>
> Should I add the explanation in commit log, or comments in the source,
> or both?
Yes please, add the explanation in the commit log and experimental comment
in the config.
> -----Original Message-----
> From: Thomas Monjalon [mailto:thomas@monjalon.net]
> Sent: Thursday, April 27, 2017 5:20 PM
> To: Wang, Zhihong <zhihong.wang@intel.com>
> Cc: Richardson, Bruce <bruce.richardson@intel.com>; dev@dpdk.org;
> yuanhan.liu@linux.intel.com
> Subject: Re: [dpdk-dev] [PATCH] config: make AVX and AVX512 configurable
>
> 27/04/2017 11:18, Wang, Zhihong:
> > From: Thomas Monjalon [mailto:thomas@monjalon.net]
> > > 27/04/2017 18:34, Zhihong Wang:
> > > > Making AVX and AVX512 configurable is useful for performance and
> power
> > > > testing.
> > > >
> > > > The similar kernel patch at
> https://patchwork.kernel.org/patch/9618883/.
> > > [...]
> > > > +#
> > > > +# Recognize/ignore the AVX/AVX512 CPU flags for
> performance/power
> > > testing
> > > > +#
> > > > +CONFIG_RTE_ENABLE_AVX=y
> > > > +CONFIG_RTE_ENABLE_AVX512=n
> > >
> > > It is disabling AVX512 in default configuration.
> > > Please explain this behaviour change.
> >
> > Though AVX512 rte_memcpy has been in DPDK for quite a while it's still
> > unproven in hardware with rich use cases. Mark it as experimental for
> > now, user can enable it for their own testing.
> >
> > Will enable it with enough field tests and possible optimization.
> >
> > Should I add the explanation in commit log, or comments in the source,
> > or both?
>
> Yes please, add the explanation in the commit log and experimental
> comment
> in the config.
Thanks a lot! It's included in v2.
@@ -103,6 +103,12 @@ CONFIG_RTE_EAL_IGB_UIO=n
CONFIG_RTE_EAL_VFIO=n
CONFIG_RTE_MALLOC_DEBUG=n
+#
+# Recognize/ignore the AVX/AVX512 CPU flags for performance/power testing
+#
+CONFIG_RTE_ENABLE_AVX=y
+CONFIG_RTE_ENABLE_AVX512=n
+
# Default driver path (or "" to disable)
CONFIG_RTE_EAL_PMD_PATH=""
@@ -70,8 +70,10 @@ CPUFLAGS += PCLMULQDQ
endif
ifneq ($(filter $(AUTO_CPUFLAGS),__AVX__),)
+ifeq ($(CONFIG_RTE_ENABLE_AVX),y)
CPUFLAGS += AVX
endif
+endif
ifneq ($(filter $(AUTO_CPUFLAGS),__RDRND__),)
CPUFLAGS += RDRAND
@@ -86,12 +88,16 @@ CPUFLAGS += F16C
endif
ifneq ($(filter $(AUTO_CPUFLAGS),__AVX2__),)
+ifeq ($(CONFIG_RTE_ENABLE_AVX),y)
CPUFLAGS += AVX2
endif
+endif
ifneq ($(filter $(AUTO_CPUFLAGS),__AVX512F__),)
+ifeq ($(CONFIG_RTE_ENABLE_AVX512),y)
CPUFLAGS += AVX512F
endif
+endif
# IBM Power CPU flags
ifneq ($(filter $(AUTO_CPUFLAGS),__PPC64__),)