Re: [dpdk-dev] [PATCH v2 0/2] dpdk: Allow for dynamic enablement of some isolated features

["Ananyev, Konstantin" <konstantin.ananyev@intel.com>]

> -----Original Message-----
> From: Neil Horman [mailto:nhorman@tuxdriver.com]
> Sent: Wednesday, July 30, 2014 3:49 PM
> To: dev@dpdk.org
> Cc: Ananyev, Konstantin; Neil Horman; Thomas Monjalon
> Subject: [PATCH v2 0/2] dpdk: Allow for dynamic enablement of some isolated features
> 
> Hey all-
>         I've been trying to update the fedora dpdk package to support VFIO
> enabled drivers and ran into a problem in which ixgbe didn't compile because the
> rxtx_vec code uses sse4.2 instruction intrinsics, which aren't supported in the
> default config I have.  I tried to remedy this by replacing the intrinsics with
> the __builtin macros, but it was pointed out (correctly), that this doesn't work
> properly.  So this is my second attempt, which I actually like a bit better.  I
> noted that code that uses intrinsics (ixgbe and the acl library), don't need to
> have those instructions turned on build-wide.  Rather, we can just enable the
> instructions in the specific code we want to build with support for that, and
> test for instruction support dynamically at run time.  This allows me to build
> the dpdk for a generic platform, but in such a way that some optimizations can
> be used if the executing cpu supports them at run time.
> 
> Change notes:
> 
> v2)
> 	* Added Log messages to run time check failures per Konstantin
> 	* Removed run time check caching in acl per Konstantin
> 
> Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
> CC: Thomas Monjalon <thomas.monjalon@6wind.com>

Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>