From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp.tuxdriver.com (charlotte.tuxdriver.com [70.61.120.58]) by dpdk.org (Postfix) with ESMTP id 5F4EAADBE for ; Wed, 30 Jul 2014 21:32:15 +0200 (CEST) Received: from hmsreliant.think-freely.org ([2001:470:8:a08:7aac:c0ff:fec2:933b] helo=localhost) by smtp.tuxdriver.com with esmtpsa (TLSv1:AES128-SHA:128) (Exim 4.63) (envelope-from ) id 1XCZdU-00006r-Tb; Wed, 30 Jul 2014 15:34:10 -0400 Date: Wed, 30 Jul 2014 15:34:04 -0400 From: Neil Horman To: Venky Venkatesan Message-ID: <20140730193404.GC3296@hmsreliant.think-freely.org> References: <1406665466-29654-1-git-send-email-nhorman@tuxdriver.com> <1406731769-18523-1-git-send-email-nhorman@tuxdriver.com> <53D9418A.5020308@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <53D9418A.5020308@intel.com> User-Agent: Mutt/1.5.23 (2014-03-12) X-Spam-Score: -2.9 (--) X-Spam-Status: No Cc: dev@dpdk.org Subject: Re: [dpdk-dev] [PATCH v2 0/2] dpdk: Allow for dynamic enablement of some isolated features X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 30 Jul 2014 19:32:15 -0000 On Wed, Jul 30, 2014 at 12:03:38PM -0700, Venky Venkatesan wrote: > Neil, > > >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 > >CC: Thomas Monjalon > > > > One possible change to look at - the _mm_shuffle_epi8 is something that is > available all the way from SSSE3, so you should be able to leave that in. > The SSE4.2 dependency is only for the popcount (and __builtin_popcountll > will work for that anyway). That should make things simpler. > > -Venky > ugh, actually both the ixgbe and acl libraries use the popcnt instruction, so I think I'd rather just keep the sse4.2 instruction set as it is, unless you think the __builtin_popcnt is equally performant. Neil