From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id 8B99DA0A0C; Wed, 4 Aug 2021 15:30:29 +0200 (CEST) Received: from [217.70.189.124] (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 1ACC24014F; Wed, 4 Aug 2021 15:30:29 +0200 (CEST) Received: from new2-smtp.messagingengine.com (new2-smtp.messagingengine.com [66.111.4.224]) by mails.dpdk.org (Postfix) with ESMTP id 76FC94003E for ; Wed, 4 Aug 2021 15:30:27 +0200 (CEST) Received: from compute6.internal (compute6.nyi.internal [10.202.2.46]) by mailnew.nyi.internal (Postfix) with ESMTP id BF72B580B6F; Wed, 4 Aug 2021 09:30:26 -0400 (EDT) Received: from mailfrontend1 ([10.202.2.162]) by compute6.internal (MEProxy); Wed, 04 Aug 2021 09:30:26 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=monjalon.net; h= from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; s=fm1; bh=XMynmq4pDnnew Kk+X3ZWTfLdAIod3Wt4Zb5hGrKUM30=; b=MyHwk9zHNId21jy9ER8+hrXIDh2M/ drFRs6bE/ZHmDY4OBiAMPkt7mQLerRj8d4xgSUD+a7dehZ8vZkR7RvMWuolN5UXh e+EKKce9jT7pRl2xI6q1byu0GU4+e1Gr/b0ufw7qd0izfk/WbagJqiLSbdm4eQjC kZKGTgkcimsLmkCdTmvglV3SHIemN2dDmXhShnNuLqn2eQnQQd2yeTuL90qHUdvt DQUL0cCLRjggqbeCZhi3waVMXiWCVjjB/YZtDEUtEDGToWhrRGdJWy0UWYzleJWF 7Fbnbhb6n+qr2aBZ2zHcrwag42FR578kWG25/ZIB3qd4pgL53FIUzHmxQ== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:date:from :in-reply-to:message-id:mime-version:references:subject:to :x-me-proxy:x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s= fm3; bh=XMynmq4pDnnewKk+X3ZWTfLdAIod3Wt4Zb5hGrKUM30=; b=ozmtVHor rMO/AZl7hbQ5J9pUe2P73Z9Y+OUh0UYc4OxgW+6A8o8NieDldoVawjTl5bKE8/AD OGL/SHT9gJSCbRM7wPLHtKX0clwD0xNVDdoOOkaBFRB0hseTBPwpcFznOyzWUDk9 VnAMAGmU5TJZjdUvDDzPOEd8kuFAISkUxtUX3BLRp02R9SpF1JBcni+R4Kg3aeSp tifzuQOSyINXvMAJwT5GXsy7pelMVD+XLy3IppJhYuaWXlXIn7RMOMJ2RM0MOwl6 TbHCtIuhN8Na4qlHyELI6xEPC52f/YuaSLpYAZ+naH1+PrVdgJeDvi9e+Qg283Yt dS8ZsMtCmiOXXg== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvtddrieejgdegjecutefuodetggdotefrodftvf curfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfghnecu uegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenuc fjughrpefhvffufffkofgjfhgggfestdekredtredttdenucfhrhhomhepvfhhohhmrghs ucfoohhnjhgrlhhonhcuoehthhhomhgrshesmhhonhhjrghlohhnrdhnvghtqeenucggtf frrghtthgvrhhnpedvhefgiedvjeegtdevheefhfetleefgfeivefgffevfeejgedtgfeu tdehtdegveenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepmhgrihhlfhhroh hmpehthhhomhgrshesmhhonhhjrghlohhnrdhnvght X-ME-Proxy: Received: by mail.messagingengine.com (Postfix) with ESMTPA; Wed, 4 Aug 2021 09:30:23 -0400 (EDT) From: Thomas Monjalon To: dev@dpdk.org Cc: mb@smartsharesystems.com, alialnu@nvidia.com, david.marchand@redhat.com, akozyrev@nvidia.com, viacheslavo@nvidia.com, ferruh.yigit@intel.com, andrew.rybchenko@oktetlabs.ru, konstantin.ananyev@intel.com, ajit.khaparde@broadcom.com, Olivier Matz Date: Wed, 4 Aug 2021 15:29:52 +0200 Message-Id: <20210804132952.2674942-1-thomas@monjalon.net> X-Mailer: git-send-email 2.31.1 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Subject: [dpdk-dev] [PATCH] doc: add known issue with mbuf segment X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" A bug with segmented packets has been discovered but the agreement to apply the fix is not concluded at the time of DPDK 21.08 release. This bug seems to be in DPDK for many years and should be fixed in 21.11. Suggested-by: Olivier Matz Signed-off-by: Thomas Monjalon --- doc/guides/rel_notes/release_21_08.rst | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/doc/guides/rel_notes/release_21_08.rst b/doc/guides/rel_notes/release_21_08.rst index d7559ec6bf..14e32585b8 100644 --- a/doc/guides/rel_notes/release_21_08.rst +++ b/doc/guides/rel_notes/release_21_08.rst @@ -251,6 +251,18 @@ Known Issues Also, make sure to start the actual text at the margin. ======================================================= +* **Last mbuf segment not implicitly reset.** + + It is expected that free mbufs have their field ``nb_seg`` set to 1, + so that when it is allocated, the user does not need to set its value. + The mbuf free functions are responsible of resetting this field to 1 + before returning the mbuf to the pool. + + When a multi-segment mbuf is freed, the field ``nb_seg`` is not reset + to 1 for the last segment of the chain. On next allocation of this segment, + if the field is not explicitly reset by the user, + an invalid mbuf can be created, and can cause an undefined behavior. + Tested Platforms ---------------- -- 2.31.1