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From: Neil Horman <nhorman@tuxdriver.com>
To: "Ananyev, Konstantin" <konstantin.ananyev@intel.com>
Cc: "dev@dpdk.org" <dev@dpdk.org>
Subject: Re: [dpdk-dev] [PATCH 0/2] dpdk: Allow for dynamic enablement of some	isolated features
Date: Wed, 30 Jul 2014 09:01:10 -0400	[thread overview]
Message-ID: <20140730130109.GA19737@localhost.localdomain> (raw)
In-Reply-To: <2601191342CEEE43887BDE71AB97725821345777@IRSMSX105.ger.corp.intel.com>

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
> 
> 

  reply	other threads:[~2014-07-30 12:59 UTC|newest]

Thread overview: 45+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-07-29 20:24 Neil Horman
2014-07-29 20:24 ` [dpdk-dev] [PATCH 1/2] ixgbe: test sse4.2 support at runtime for vectorized receive operations Neil Horman
2014-07-29 20:24 ` [dpdk-dev] [PATCH 2/2] acl: Preform dynamic sse4.2 support check Neil Horman
2014-07-30 12:07 ` [dpdk-dev] [PATCH 0/2] dpdk: Allow for dynamic enablement of some isolated features Ananyev, Konstantin
2014-07-30 13:01   ` Neil Horman [this message]
2014-07-30 13:44     ` Ananyev, Konstantin
2014-07-30 14:49 ` [dpdk-dev] [PATCH v2 " Neil Horman
2014-07-30 14:49   ` [dpdk-dev] [PATCH v2 1/2] ixgbe: test sse4.2 support at runtime for vectorized receive operations Neil Horman
2014-07-30 14:49   ` [dpdk-dev] [PATCH v2 2/2] acl: Preform dynamic sse4.2 support check Neil Horman
2014-07-30 15:36   ` [dpdk-dev] [PATCH v2 0/2] dpdk: Allow for dynamic enablement of some isolated features Ananyev, Konstantin
2014-07-30 19:03   ` Venky Venkatesan
2014-07-30 19:17     ` Neil Horman
2014-07-30 19:34     ` Neil Horman
2014-07-30 18:59 ` [dpdk-dev] [PATCH " Bruce Richardson
2014-07-30 19:28   ` Neil Horman
2014-07-30 21:09     ` Bruce Richardson
2014-07-31  9:30       ` Thomas Monjalon
2014-07-31 11:36       ` Ananyev, Konstantin
2014-07-31 13:13       ` Neil Horman
2014-07-31 13:26         ` Thomas Monjalon
2014-07-31 14:32           ` Neil Horman
2014-07-31 18:10             ` Neil Horman
2014-07-31 18:36               ` Bruce Richardson
2014-07-31 19:01                 ` Neil Horman
2014-07-31 20:19                   ` Bruce Richardson
2014-08-01 13:36                     ` Neil Horman
2014-08-01 13:56                       ` Ananyev, Konstantin
2014-08-01 14:26                         ` Venkatesan, Venky
2014-08-01 14:27                         ` Neil Horman
2014-07-31 19:58                 ` John W. Linville
2014-07-31 20:20                   ` Bruce Richardson
2014-07-31 20:32                     ` John W. Linville
2014-08-01  8:46                       ` Vincent JARDIN
2014-08-01 14:06                         ` Neil Horman
2014-08-01 14:57                           ` Vincent JARDIN
2014-08-01 15:19                             ` Neil Horman
2014-07-31 20:10                 ` Neil Horman
2014-07-31 20:25                   ` Bruce Richardson
2014-08-01 15:06                     ` Neil Horman
2014-08-01 19:22                       ` Bruce Richardson
2014-08-01 20:43                         ` Neil Horman
2014-08-01 21:08                           ` Bruce Richardson
2014-08-02 12:56                             ` Neil Horman
2014-07-31 21:53               ` Thomas Monjalon
2014-07-31 21:25             ` Thomas Monjalon

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