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 14261A0A02;
	Tue, 27 Apr 2021 15:57:31 +0200 (CEST)
Received: from [217.70.189.124] (localhost [127.0.0.1])
	by mails.dpdk.org (Postfix) with ESMTP id CFE004124C;
	Tue, 27 Apr 2021 15:57:30 +0200 (CEST)
Received: from mail-wr1-f42.google.com (mail-wr1-f42.google.com
 [209.85.221.42]) by mails.dpdk.org (Postfix) with ESMTP id A2C6A41243
 for <dev@dpdk.org>; Tue, 27 Apr 2021 15:57:29 +0200 (CEST)
Received: by mail-wr1-f42.google.com with SMTP id n2so6416298wrm.0
 for <dev@dpdk.org>; Tue, 27 Apr 2021 06:57:29 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=6wind.com; s=google;
 h=from:to:cc:subject:date:message-id:in-reply-to:references
 :mime-version:content-transfer-encoding;
 bh=vos3FyYYsV04l2bLFI52GjyRQbLDhDV0DMug0ubWDeE=;
 b=Nip68lZJtHHogTtSM3T68BX2vHYRlbcGt/ssGzdW+3tnz5Q0hv+zD6yoC7GScgjQkM
 vf0XVSetKfcT3VYYu+SgoxjLvQ+vya4zx5K3EBztP6FMgZmSeSteRRr3v1TF6PLX0wdI
 QFHzzpgkzB/Rx8RlX9iOmxI4+u6EEyqK7C0WlnRQxDJ04BvAhmzc+R03IGTQszFizoX5
 Nvn2dq17eeeoDbeWXg6Qfb+tBgzrjuDprWR4bH9RKB6I5VVx3i9pfb7dwe7HSgHnMAKA
 ckX9hDM8H5YE2X8Vyw3zUak9GaVKSsywUe/YjfcwM4VuMr56aypEmFPC2+aVlz+vqgWe
 P+aw==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
 d=1e100.net; s=20161025;
 h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to
 :references:mime-version:content-transfer-encoding;
 bh=vos3FyYYsV04l2bLFI52GjyRQbLDhDV0DMug0ubWDeE=;
 b=AlLlC703cqhxXxwrwRHiH0TtMEFO9OeJRCU5urreXqbqdf7vUv6lLuiG0GzWqhSf6V
 TrJKD5dOxQTzz1Z+rqETRB73SpziIVjRm4S/rbv3WDyYkmM6iCd7LHg6d+vSdQGWScJC
 s+bX0tqJiwKy8O+m6SvQvMJCtYRl7SJGvys9ZR/oGwhcf7mxkAv5Kru8xL46SENL8h2M
 5dGwE4IY6ODxqrkV5fg0b+8WbbpeKJpWnU/MMHFBFy8jFcP9TibaWuUmUKi1CtTnW8Jk
 iu1TE7GvwgdsHHFJAWzaVK9LBVWHPCMarTeDuOaHAwdxysnkX7b8IQgNUwXm+nQysPu1
 RZyA==
X-Gm-Message-State: AOAM530P5zcKpdXT3At5Aslp1oB2F8GPnKWhncpTOfyBJnjkmr9raRI7
 CebKEtHPs9XAvu7vCi+iN52UK8YNLOS9iw==
X-Google-Smtp-Source: ABdhPJwKb4lxb2LsMTpxjH3g45QZ6ltPL43lsNv5R0mJVo/5xs42WgGYxQwdBdKv8vqw4K+HzEzCfQ==
X-Received: by 2002:a05:6000:10:: with SMTP id
 h16mr8717009wrx.381.1619531849435; 
 Tue, 27 Apr 2021 06:57:29 -0700 (PDT)
Received: from gojira.dev.6wind.com (host.78.145.23.62.rev.coltfrance.com.
 [62.23.145.78])
 by smtp.gmail.com with ESMTPSA id m14sm11760341wmi.39.2021.04.27.06.57.28
 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256);
 Tue, 27 Apr 2021 06:57:29 -0700 (PDT)
From: Olivier Matz <olivier.matz@6wind.com>
To: dev@dpdk.org
Cc: Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>,
 Pallantla Poornima <pallantlax.poornima@intel.com>,
 Wenwu Ma <wenwux.ma@intel.com>, Peng Zhihong <zhihongx.peng@intel.com>,
 Aaron Conole <aconole@redhat.com>, Thomas Monjalon <thomas@monjalon.net>
Date: Tue, 27 Apr 2021 15:56:46 +0200
Message-Id: <20210427135646.871-2-olivier.matz@6wind.com>
X-Mailer: git-send-email 2.29.2
In-Reply-To: <20210427135646.871-1-olivier.matz@6wind.com>
References: <20210413200513.330399-1-wenwux.ma@intel.com>
 <20210427135646.871-1-olivier.matz@6wind.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Subject: [dpdk-dev] [PATCH v3 2/2] mbuf: better document usage of packet
 pool initializers
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
Sender: "dev" <dev-bounces@dpdk.org>

Clarify that the mempool private initializer and object initializer used
for packet pools require that the mempool private size is large enough.

Also add an assert (only enabled when -DRTE_ENABLE_ASSERT is passed) to
check this constraint.

Signed-off-by: Olivier Matz <olivier.matz@6wind.com>
---
 lib/mbuf/rte_mbuf.c | 5 +++++
 lib/mbuf/rte_mbuf.h | 8 +++++++-
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/lib/mbuf/rte_mbuf.c b/lib/mbuf/rte_mbuf.c
index 3ff0a69187..f7e3c1a187 100644
--- a/lib/mbuf/rte_mbuf.c
+++ b/lib/mbuf/rte_mbuf.c
@@ -43,6 +43,8 @@ rte_pktmbuf_pool_init(struct rte_mempool *mp, void *opaque_arg)
 	struct rte_pktmbuf_pool_private default_mbp_priv;
 	uint16_t roomsz;
 
+	RTE_ASSERT(mp->private_data_size >=
+		   sizeof(struct rte_pktmbuf_pool_private));
 	RTE_ASSERT(mp->elt_size >= sizeof(struct rte_mbuf));
 
 	/* if no structure is provided, assume no mbuf private area */
@@ -83,6 +85,9 @@ rte_pktmbuf_init(struct rte_mempool *mp,
 	struct rte_mbuf *m = _m;
 	uint32_t mbuf_size, buf_len, priv_size;
 
+	RTE_ASSERT(mp->private_data_size >=
+		   sizeof(struct rte_pktmbuf_pool_private));
+
 	priv_size = rte_pktmbuf_priv_size(mp);
 	mbuf_size = sizeof(struct rte_mbuf) + priv_size;
 	buf_len = rte_pktmbuf_data_room_size(mp);
diff --git a/lib/mbuf/rte_mbuf.h b/lib/mbuf/rte_mbuf.h
index c4c9ebfaa0..a555f216ae 100644
--- a/lib/mbuf/rte_mbuf.h
+++ b/lib/mbuf/rte_mbuf.h
@@ -624,6 +624,9 @@ rte_mbuf_raw_free(struct rte_mbuf *m)
  * address, and so on). This function is given as a callback function to
  * rte_mempool_obj_iter() or rte_mempool_create() at pool creation time.
  *
+ * This function expects that the mempool private area was previously
+ * initialized with rte_pktmbuf_pool_init().
+ *
  * @param mp
  *   The mempool from which mbufs originate.
  * @param opaque_arg
@@ -639,7 +642,7 @@ void rte_pktmbuf_init(struct rte_mempool *mp, void *opaque_arg,
 		      void *m, unsigned i);
 
 /**
- * A  packet mbuf pool constructor.
+ * A packet mbuf pool constructor.
  *
  * This function initializes the mempool private data in the case of a
  * pktmbuf pool. This private data is needed by the driver. The
@@ -648,6 +651,9 @@ void rte_pktmbuf_init(struct rte_mempool *mp, void *opaque_arg,
  * pool creation. It can be extended by the user, for example, to
  * provide another packet size.
  *
+ * The mempool private area size must be at least equal to
+ * sizeof(struct rte_pktmbuf_pool_private).
+ *
  * @param mp
  *   The mempool from which mbufs originate.
  * @param opaque_arg
-- 
2.29.2