From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <dev-bounces@dpdk.org>
Received: from dpdk.org (dpdk.org [92.243.14.124])
	by inbox.dpdk.org (Postfix) with ESMTP id CB5DCA0350;
	Mon, 18 Nov 2019 17:12:09 +0100 (CET)
Received: from [92.243.14.124] (localhost [127.0.0.1])
	by dpdk.org (Postfix) with ESMTP id C4323B62;
	Mon, 18 Nov 2019 17:12:08 +0100 (CET)
Received: from mail-pf1-f193.google.com (mail-pf1-f193.google.com
 [209.85.210.193]) by dpdk.org (Postfix) with ESMTP id 4803FA3
 for <dev@dpdk.org>; Mon, 18 Nov 2019 17:12:07 +0100 (CET)
Received: by mail-pf1-f193.google.com with SMTP id x28so10612381pfo.6
 for <dev@dpdk.org>; Mon, 18 Nov 2019 08:12:07 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
 d=networkplumber-org.20150623.gappssmtp.com; s=20150623;
 h=date:from:to:cc:subject:message-id:in-reply-to:references
 :mime-version:content-transfer-encoding;
 bh=JEPWVJpLsJPCkkZQAy+JJV2fq9t+M+k5zucfUdh27XI=;
 b=fuYk7y+F5+CJrMrFH+TJnySiU99q5b0tlodKygqG6TSm0uQsUw5dIZvna8w5Z8dsnu
 z5oTvEek2UZoI/cvm7Xujs/EVYK/tadfX+KobUKTLom4t4YLG3ujIBicLNW71BTJXh2a
 MZbZQpDMnTNxH3laRsv9E5Zd/agB0pSZ+NZLun7bLjtX2hy1hQ1wTBhQ0lb76AjqGvGx
 dGXWo/n1Q2lRQmTUmoVzaGrVZqvZSHosi0idH73ECDj7dpHDoeEmXzcQvoNiyfYoRMyR
 Fx3Qf4WBMfdvkY5zSGbiSaKMBks4SCqRNzUnjOyQt5sSS4SP72tp4/q+Tr6XuuJBBmN8
 +t7A==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
 d=1e100.net; s=20161025;
 h=x-gm-message-state:date:from:to:cc:subject:message-id:in-reply-to
 :references:mime-version:content-transfer-encoding;
 bh=JEPWVJpLsJPCkkZQAy+JJV2fq9t+M+k5zucfUdh27XI=;
 b=lkNKwYNVWkPQMRgawwhJkyUCAyWXKjp+KKy/E3LYyAjdn2rNFd6nyndmWjlW9kmeTb
 YCCau54jDq7aG1sItjD/a0X3t2kBnrcU8pgqCDrp4BnOhnX7mOWBjlLNBTIaJNDfqa6z
 3VJPGPfoHgYnj3XXThYDeW0Qk5hG4jz4+GdxlLXRw5VcZclPTLlV0Dolp1vcF5WG9Fz6
 XMshf2Rm4j/okPDeKhtMz1Ewj7ueaOnTYUB2zIDZ3ZnoBa7kNUD9NnoOJDcsu1UotAqH
 lyE2h34caYoex3C0hVyddBfenTHZhFbGI+NvdUohwgAjEAKgMA0UCHvK0qbRXMdIDS+9
 FZPg==
X-Gm-Message-State: APjAAAWJRzjRSXhppq0YtM5lObthSVgxOCSYczB32hcIiSzE4yR5lF/f
 ouSB86+Qbfq55AtTk/aE+1/lag==
X-Google-Smtp-Source: APXvYqxSKHlSYNZxtRB93DUzq1Zd1V0ufQC4r1ezyVvI0G7yZhs1pWFG01Rr3MHkkqVvhwnulvdNKA==
X-Received: by 2002:aa7:9348:: with SMTP id 8mr17293pfn.135.1574093526439;
 Mon, 18 Nov 2019 08:12:06 -0800 (PST)
Received: from hermes.lan (204-195-22-127.wavecable.com. [204.195.22.127])
 by smtp.gmail.com with ESMTPSA id 12sm21304969pjm.11.2019.11.18.08.12.05
 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256);
 Mon, 18 Nov 2019 08:12:06 -0800 (PST)
Date: Mon, 18 Nov 2019 08:12:03 -0800
From: Stephen Hemminger <stephen@networkplumber.org>
To: Shahaf Shuler <shahafs@mellanox.com>
Cc: "olivier.matz@6wind.com" <olivier.matz@6wind.com>, Thomas Monjalon
 <thomas@monjalon.net>, "dev@dpdk.org" <dev@dpdk.org>
Message-ID: <20191118081203.3e4980f0@hermes.lan>
In-Reply-To: <20191118100247.74241-1-shahafs@mellanox.com>
References: <20191118100247.74241-1-shahafs@mellanox.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Subject: Re: [dpdk-dev] [PATCH] mbuf: extend pktmbuf pool private structure
X-BeenThere: dev@dpdk.org
X-Mailman-Version: 2.1.15
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
Sender: "dev" <dev-bounces@dpdk.org>

On Mon, 18 Nov 2019 10:02:55 +0000
Shahaf Shuler <shahafs@mellanox.com> wrote:

> With the API and ABI freeze ahead, it will be good to reserve
> some bits on the private structure for future use.
> 
> Otherwise we will potentially need to maintain two different
> private structure during 2020 period.
> 
> There is already one use case for those reserved bits[1]
> 
> The reserved field should be set to 0 by the user.
> 
> [1]
> https://patches.dpdk.org/patch/63077/
> 
> Signed-off-by: Shahaf Shuler <shahafs@mellanox.com>
> ---

Understand the motivation but in my experience until you know
what it is for, this doesn't work. And it creates lots of dead ends.

https://en.wikipedia.org/wiki/You_aren%27t_gonna_need_it