On Wed, Jul 30, 2014 at 12:07:39PM +0000, Ananyev, Konstantin wrote: > > > Hi 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. > > Indeed it looks much better to me too. > Just few nits from me: > > 1. > @@ -112,6 +112,15 @@ rte_acl_create(const struct rte_acl_param *param) > > struct rte_acl_list *acl_list; > > struct rte_tailq_entry *te; > > char name[sizeof(ctx->name)]; > > + static int acl_supported = -1; > > + > > + if (acl_supported == -1) > > + acl_supported = rte_cpu_get_flag_enabled(RTE_CPUFLAG_SSE4_2); > > Do we really need acl_supported here? > It seems not a big deal to just always call rte_cpu_get_flag_enabled(). > After all it is a create function, and no-one expects it to be extremely fast. > Need, no. My only thought was that some poorly behaved application will call rte_acl_create multiple times regardless of the error returned, and doing so will cause large volumes of calls to cpuid, which evicts several high-use registers, so I didn't want to call it more than needed. If you think its ok to call it multiple times though, I'm fine with removing it.
> 2. Can you add RTE_LOG(ERR, ...) for re_acl_create() and > ixgbe_rx_vec_condition_check() if sse4.2 is not supported? > Absolutely, v2 shortly. Neil > Konstantin > >
