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From: Olivier Matz <olivier.matz@6wind.com>
To: "Wiles, Keith" <keith.wiles@intel.com>
Cc: "Morten Brørup" <mb@smartsharesystems.com>,
	"Honnappa Nagarahalli" <Honnappa.Nagarahalli@arm.com>,
	"dev@dpdk.org" <dev@dpdk.org>
Subject: Re: [dpdk-dev] rte_mbuf library likely()/unlikely()
Date: Tue, 24 Jul 2018 09:29:15 +0200	[thread overview]
Message-ID: <20180724072915.tc66rnjxx6lbbvb4@platinum> (raw)
In-Reply-To: <1220B8CA-FF5E-4632-81E4-E2A5243005BF@intel.com>

Hi,

On Mon, Jul 23, 2018 at 10:40:03PM +0000, Wiles, Keith wrote:
> 
> 
> > On Jul 23, 2018, at 2:09 PM, Morten Brørup <mb@smartsharesystems.com> wrote:
> > 
> > I haven't performance tested, but they are compiler branch prediction hints pointing out the most likely execution path, so I expect them to have a positive effect.
> 
> We really need to make sure this provides any performance improvement and that means it needs to be tested on a number of systems. Can you please do some performance testing or see if we can get the guys doing DPDK performance testing to first give this a try? This area is very sensitive to tweaking.

I agree we should be driven by performance improvements.

I remember a discussion with Bruce on the ML saying that hardware branch
predictors generally do a good job.

Thanks,
Olivier

  reply	other threads:[~2018-07-24  7:29 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-07-23 13:53 Morten Brørup
2018-07-23 17:37 ` Stephen Hemminger
2018-07-23 18:59   ` Morten Brørup
2018-07-23 19:45     ` Stephen Hemminger
2018-07-23 17:51 ` Honnappa Nagarahalli
2018-07-23 19:09   ` Morten Brørup
2018-07-23 22:40     ` Wiles, Keith
2018-07-24  7:29       ` Olivier Matz [this message]
2018-07-24  8:13         ` Morten Brørup
2018-07-24 11:31           ` Van Haaren, Harry
2018-07-24 13:02             ` Wiles, Keith

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