From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <dev-bounces@dpdk.org>
Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124])
	by inbox.dpdk.org (Postfix) with ESMTP id 7AC834596E;
	Thu, 12 Sep 2024 15:20:28 +0200 (CEST)
Received: from mails.dpdk.org (localhost [127.0.0.1])
	by mails.dpdk.org (Postfix) with ESMTP id 60B42427D3;
	Thu, 12 Sep 2024 15:20:28 +0200 (CEST)
Received: from mail.lysator.liu.se (mail.lysator.liu.se [130.236.254.3])
 by mails.dpdk.org (Postfix) with ESMTP id 0C9D642709
 for <dev@dpdk.org>; Thu, 12 Sep 2024 15:20:27 +0200 (CEST)
Received: from mail.lysator.liu.se (localhost [127.0.0.1])
 by mail.lysator.liu.se (Postfix) with ESMTP id D03D44F76
 for <dev@dpdk.org>; Thu, 12 Sep 2024 15:20:26 +0200 (CEST)
Received: by mail.lysator.liu.se (Postfix, from userid 1004)
 id C405E5088; Thu, 12 Sep 2024 15:20:26 +0200 (CEST)
X-Spam-Checker-Version: SpamAssassin 4.0.0 (2022-12-13) on
 hermod.lysator.liu.se
X-Spam-Level: 
X-Spam-Status: No, score=-1.2 required=5.0 tests=ALL_TRUSTED,AWL,
 T_SCC_BODY_TEXT_LINE autolearn=disabled version=4.0.0
X-Spam-Score: -1.2
Received: from [192.168.1.86] (h-62-63-215-114.A163.priv.bahnhof.se
 [62.63.215.114])
 (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)
 key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256)
 (No client certificate requested)
 by mail.lysator.liu.se (Postfix) with ESMTPSA id ECA64501D;
 Thu, 12 Sep 2024 15:20:22 +0200 (CEST)
Message-ID: <88a778d3-e157-41cd-9da7-2d06864a654d@lysator.liu.se>
Date: Thu, 12 Sep 2024 15:20:22 +0200
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Subject: Re: [PATCH v3 3/7] eal: add lcore variable performance test
To: Jerin Jacob <jerinjacobk@gmail.com>,
 =?UTF-8?Q?Mattias_R=C3=B6nnblom?= <mattias.ronnblom@ericsson.com>
Cc: dev@dpdk.org, =?UTF-8?Q?Morten_Br=C3=B8rup?= <mb@smartsharesystems.com>,
 Stephen Hemminger <stephen@networkplumber.org>,
 Konstantin Ananyev <konstantin.v.ananyev@yandex.ru>,
 David Marchand <david.marchand@redhat.com>, Jerin Jacob <jerinj@marvell.com>
References: <20240911170430.701685-2-mattias.ronnblom@ericsson.com>
 <20240912084429.703405-1-mattias.ronnblom@ericsson.com>
 <20240912084429.703405-4-mattias.ronnblom@ericsson.com>
 <CALBAE1N-GDbTwNbZDVcQSUn3T-bVSVo4Ckeu3DMz=m2cZqFqYQ@mail.gmail.com>
Content-Language: en-US
From: =?UTF-8?Q?Mattias_R=C3=B6nnblom?= <hofors@lysator.liu.se>
In-Reply-To: <CALBAE1N-GDbTwNbZDVcQSUn3T-bVSVo4Ckeu3DMz=m2cZqFqYQ@mail.gmail.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
X-Virus-Scanned: ClamAV using ClamSMTP
X-BeenThere: dev@dpdk.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: DPDK patches and discussions <dev.dpdk.org>
List-Unsubscribe: <https://mails.dpdk.org/options/dev>,
 <mailto:dev-request@dpdk.org?subject=unsubscribe>
List-Archive: <http://mails.dpdk.org/archives/dev/>
List-Post: <mailto:dev@dpdk.org>
List-Help: <mailto:dev-request@dpdk.org?subject=help>
List-Subscribe: <https://mails.dpdk.org/listinfo/dev>,
 <mailto:dev-request@dpdk.org?subject=subscribe>
Errors-To: dev-bounces@dpdk.org

On 2024-09-12 15:09, Jerin Jacob wrote:
> On Thu, Sep 12, 2024 at 2:34 PM Mattias Rönnblom
> <mattias.ronnblom@ericsson.com> wrote:
>>
>> Add basic micro benchmark for lcore variables, in an attempt to assure
>> that the overhead isn't significantly greater than alternative
>> approaches, in scenarios where the benefits aren't expected to show up
>> (i.e., when plenty of cache is available compared to the working set
>> size of the per-lcore data).
>>
>> Signed-off-by: Mattias Rönnblom <mattias.ronnblom@ericsson.com>
>> ---
>>   app/test/meson.build           |   1 +
>>   app/test/test_lcore_var_perf.c | 160 +++++++++++++++++++++++++++++++++
>>   2 files changed, 161 insertions(+)
>>   create mode 100644 app/test/test_lcore_var_perf.c
> 
> 
>> +static double
>> +benchmark_access_method(void (*init_fun)(void), void (*update_fun)(void))
>> +{
>> +       uint64_t i;
>> +       uint64_t start;
>> +       uint64_t end;
>> +       double latency;
>> +
>> +       init_fun();
>> +
>> +       start = rte_get_timer_cycles();
>> +
>> +       for (i = 0; i < ITERATIONS; i++)
>> +               update_fun();
>> +
>> +       end = rte_get_timer_cycles();
> 
> Use precise variant. rte_rdtsc_precise() or so to be accurate

With 1e7 iterations, do you need rte_rdtsc_precise()? I suspect not.