From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id D7F65A09F0 for ; Thu, 17 Dec 2020 10:29:10 +0100 (CET) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id CB9A1C9FC; Thu, 17 Dec 2020 10:29:09 +0100 (CET) Received: from mail-wm1-f44.google.com (mail-wm1-f44.google.com [209.85.128.44]) by dpdk.org (Postfix) with ESMTP id 003AFC9FC for ; Thu, 17 Dec 2020 10:29:07 +0100 (CET) Received: by mail-wm1-f44.google.com with SMTP id k10so4911342wmi.3 for ; Thu, 17 Dec 2020 01:29:07 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:message-id:subject:from:to:cc:date:in-reply-to :references:content-transfer-encoding:user-agent:mime-version; bh=tE09hLFFV2VfOLBUByf7Pw7Ssfkcs/dKUacrNde9NB4=; b=DoioZZSsaDCUunGfgJbnlZNczClLGu3MoWh8uLZrokVy4A0Fzz09u/c2G4k924GPNC qlfrOfcd0zLKXRZFnHOCb/XXSlZs6is2UkXLkeC2ex/0YdCaQB/JZ1Uw1xCWLlDh8iEi 8RLN1/JUeHrZd4QQawuT3Cg6Ak0fhaYaJrfZ6LGV0BFcdqszbcITQxmg9GWlli0f3yQc ozqlmIqKK29DGjOZbtXmbK4BZKhXBeQurUtZfbuuSnycMeFGmbwlJY4tyVrY7AB0fZ/S FmWHPJ3GIsP9wX6pkYHoVsocwf2AhmM9p4QDXXHzc3N7kTox7U9DprRrPY1hVO+3Q82R iDCQ== X-Gm-Message-State: AOAM532EpmfTO87HnYItyv+tAiKlVtDL0larFI/h1LkhyuZhio4O+nVB 8xn1ctQhCHbbm4SAw7P1m+w= X-Google-Smtp-Source: ABdhPJwiZ2mXLmAzbsOKVsMipoxfaqm34AvrPLPTKlAPAhYf6ZSRCRfbmQ0CYnBr/6H4RW57fTZJqA== X-Received: by 2002:a7b:cf08:: with SMTP id l8mr7669731wmg.189.1608197346820; Thu, 17 Dec 2020 01:29:06 -0800 (PST) Received: from localhost ([88.98.246.218]) by smtp.gmail.com with ESMTPSA id x66sm6780964wmg.26.2020.12.17.01.29.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 17 Dec 2020 01:29:06 -0800 (PST) Message-ID: From: Luca Boccassi To: Long Li , stable@dpdk.org Cc: abmarath@microsoft.com, Long Li Date: Thu, 17 Dec 2020 09:29:05 +0000 In-Reply-To: <1608143259-28440-1-git-send-email-longli@linuxonhyperv.com> References: <1608143259-28440-1-git-send-email-longli@linuxonhyperv.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.30.5-1.2 MIME-Version: 1.0 Subject: Re: [dpdk-stable] [PATCH 19.11] net/netvsc: disable external mbuf on Rx by default X-BeenThere: stable@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches for DPDK stable branches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: stable-bounces@dpdk.org Sender: "stable" On Wed, 2020-12-16 at 10:27 -0800, Long Li wrote: > From: Long Li >=20 > [ upstream commit 096b31fc0d8c989cc455c35f4d1def24a4ed6dee ] >=20 > The upstream commit introduces a new driver parameter and disable the use > of external mbuf by default. The same can be done by defining a max value > for the RX threshold for external mbuf. >=20 > The use of external mbuf is disabled by default for two reasons: > 1. Due to the limitation of the kernel UIO implementation, physical > address of this external buffer is not exposed to the user-mode. I= f > this mbuf is passed to another driver, the other driver is unable = to > map this buffer to iova. > 2. Some DPDK applications are not aware of external mbuf, and may bug > when they receive an mbuf with external buffer attached. >=20 > Signed-off-by: Long Li > --- > drivers/net/netvsc/hn_rxtx.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) >=20 > diff --git a/drivers/net/netvsc/hn_rxtx.c b/drivers/net/netvsc/hn_rxtx.c > index 19f00a0..d618c17 100644 > --- a/drivers/net/netvsc/hn_rxtx.c > +++ b/drivers/net/netvsc/hn_rxtx.c > @@ -42,7 +42,7 @@ > #define HN_TXD_CACHE_SIZE 32 /* per cpu tx_descriptor pool cache */ > #define HN_TXCOPY_THRESHOLD 512 > =20 > -#define HN_RXCOPY_THRESHOLD 256 > +#define HN_RXCOPY_THRESHOLD UINT_MAX > #define HN_RXQ_EVENT_DEFAULT 2048 > =20 > struct hn_rxinfo { Thank you - given the widespread breakage, adding this workaround in 19.11 looks like a good solution to me. It has been tested by QA already, so applied. --=20 Kind regards, Luca Boccassi