From: Stephen Hemminger <stephen@networkplumber.org>
To: "Mattias Rönnblom" <hofors@lysator.liu.se>
Cc: dev@dpdk.org, "Mattias Rönnblom" <mattias.ronnblom@ericsson.com>,
"Ray Kinsella" <mdr@ashroe.eu>
Subject: Re: [PATCH v4 1/3] random: add rte_drand() function
Date: Thu, 26 May 2022 08:25:14 -0700 [thread overview]
Message-ID: <20220526082514.3a9ab8ee@hermes.local> (raw)
In-Reply-To: <84afee2e-fa4c-faf1-d046-febb0ae77c09@lysator.liu.se>
On Thu, 26 May 2022 15:20:29 +0200
Mattias Rönnblom <hofors@lysator.liu.se> wrote:
> > @@ -55,6 +58,9 @@ test_rand_perf_type(enum rand_type rand_type)
> > case rand_type_64:
> > sum += rte_rand();
> > break;
> > + case rand_type_float:
> > + sum += 1000. * rte_drand();
>
> Including this floating point multiplication will lead to an
> overestimation of rte_drand() latency.
>
> You could refactor this function to be a macro, and pass the return type
> to as a parameter to this macro. I did just that, and on both an AMD
> 5900X and a Cortex-A72 it didn't add more than ~5%, so I don't think
> it's necessary.
The test is not doing anything useful with the result.
It is just a way to exercise the code.
Macros are evil, have little or no typechecking and should be avoided.
next prev parent reply other threads:[~2022-05-26 15:25 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-24 18:46 [RFT 0/2] pie: floating point fixes Stephen Hemminger
2022-05-24 18:46 ` [RFT 1/2] rte_pie: remove unnecessary floating point Stephen Hemminger
2022-05-24 18:46 ` [RFT 2/2] rte_pie: fix incorrect floating point math Stephen Hemminger
2022-05-24 19:31 ` [RFT 0/2] pie: floating point fixes Morten Brørup
2022-05-24 22:18 ` [RFT v2 0/3] pie: fix random number issues Stephen Hemminger
2022-05-24 22:18 ` [RFT v2 1/3] random: add rte_rand_float() Stephen Hemminger
2022-05-25 11:55 ` Ray Kinsella
2022-05-25 14:45 ` Mattias Rönnblom
2022-05-25 15:26 ` Morten Brørup
2022-05-25 15:45 ` Stephen Hemminger
2022-05-25 15:47 ` Stephen Hemminger
2022-05-24 22:18 ` [RFT v2 2/3] rte_pie: remove unnecessary floating point Stephen Hemminger
2022-05-24 22:18 ` [RFT v2 3/3] rte_pie: fix incorrect floating point math Stephen Hemminger
2022-05-25 17:12 ` [PATCH v3 0/3] introduce random floating point function Stephen Hemminger
2022-05-25 17:12 ` [PATCH v3 1/3] random: add rte_drand() funciton Stephen Hemminger
2022-05-25 17:12 ` [PATCH v3 2/3] rte_pie: remove unnecessary floating point Stephen Hemminger
2022-05-25 17:12 ` [PATCH v3 3/3] rte_pie: fix incorrect floating point math Stephen Hemminger
2022-05-25 20:31 ` [PATCH v4 0/3] introduce random floating point function Stephen Hemminger
2022-05-25 20:31 ` [PATCH v4 1/3] random: add rte_drand() function Stephen Hemminger
2022-05-26 9:56 ` Ray Kinsella
2022-05-26 13:20 ` Mattias Rönnblom
2022-05-26 15:25 ` Stephen Hemminger [this message]
2022-05-26 15:28 ` Stephen Hemminger
2022-05-26 20:19 ` Stephen Hemminger
2022-05-25 20:31 ` [PATCH v4 2/3] rte_pie: remove unnecessary floating point Stephen Hemminger
2022-05-25 20:31 ` [PATCH v4 3/3] rte_pie: fix incorrect floating point math Stephen Hemminger
2022-05-26 7:06 ` [PATCH v4 0/3] introduce random floating point function Morten Brørup
2022-05-26 20:26 ` [PATCH v5 " Stephen Hemminger
2022-05-26 20:26 ` [PATCH v5 1/3] random: add rte_drand() function Stephen Hemminger
2022-05-26 20:26 ` [PATCH v5 2/3] rte_pie: remove unnecessary floating point Stephen Hemminger
2022-05-30 11:50 ` Dumitrescu, Cristian
2022-06-21 8:18 ` Singh, Jasvinder
2022-05-26 20:26 ` [PATCH v5 3/3] rte_pie: fix incorrect floating point math Stephen Hemminger
2022-05-30 11:50 ` Dumitrescu, Cristian
2022-06-21 8:18 ` Singh, Jasvinder
2022-06-22 9:21 ` [PATCH v5 0/3] introduce random floating point function Thomas Monjalon
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