From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (xvm-189-124.dc0.ghst.net [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id CA495A09FF; Wed, 6 Jan 2021 21:54:45 +0100 (CET) Received: from [217.70.189.124] (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 491BA140E4A; Wed, 6 Jan 2021 21:54:45 +0100 (CET) Received: from mail-yb1-f170.google.com (mail-yb1-f170.google.com [209.85.219.170]) by mails.dpdk.org (Postfix) with ESMTP id 4911640FA7; Wed, 6 Jan 2021 21:54:44 +0100 (CET) Received: by mail-yb1-f170.google.com with SMTP id j17so4065049ybt.9; Wed, 06 Jan 2021 12:54:44 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=PeOnFS+Vrk3ufIi7F/oLaFkcjCrLfaOUlNIyB7Ja4qE=; b=jyS+P8rYYOYOIFQHRxPyqr5VXs9G+8dFplG5gqqiUB9CTQwRpzA/UxIjwitsVprHQD HiFmO1108p4zgN6BeqijCZyrtkl3RWQVg7AQdPZuCHG3sLk30AGcJVfK89K/uw59gd3F W7cP63UiZG/N3XCPK7Ph0KgQjKAcS+BVHuy+pedcA6FAwUujZ51xkLVbYnhSjT2mLKzY tGgxkRo+nqZkg4tL7uhg+xeI8SvTfxDYWM2g1RfLUvMbOlyGgyPSoCMrrydQ724KjZfA ZNWVKIWvAXaJs6C565+RGKijjFuefpvUOlNOyuPJQ/9RcoaDn7pveY2sW5QHFg2MByO6 t3uw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=PeOnFS+Vrk3ufIi7F/oLaFkcjCrLfaOUlNIyB7Ja4qE=; b=O2zeqo8U/xgCLGUjp9msOYrM+B0ThBTU0WEMXLgq3H1Jzdg+KOaIc7K8mKr1cSyAoQ fBCBEkXFICvoz5+JycnNI/ukCnQiEm4+5PvDFvtp7/Vxt6wOmufh2MzbIGKnWA34yJUp cmxQwkvE00Hc3iBXgtOntoFZnpq9WYXH1aSC9bBwrFg9didpnbVqZGf1O3cWa/vH71WH Jg59hCo2Hep+Rj0p0yYFZQRqRR9CfSk2xmBacJpLBtH8TcAT6qorz2EeNqDdX8aifGUN PRSCztfWRfRX/737Vrj1met8ICnshtcZkGT+haGM0gdg3PWkTAvgCIZ4wTYqbFQmoAls pLOg== X-Gm-Message-State: AOAM533n9HafHw1mcZ0pQCM5HGFzZJ5n726tRdzjqq4+vXyrqvPYcXA2 5CGVMWU71jiXVavRh283b7jDndC5wxYUNDwU9v0= X-Google-Smtp-Source: ABdhPJxo7PVJa+ovxur7qGo7+0FhySEr88bSnKAIxAx6s1GR9KrgIcXCTiTUv6d7CbpMfv5KDGl7+H4NduYZSPeMP08= X-Received: by 2002:a25:b115:: with SMTP id g21mr9096747ybj.184.1609966483728; Wed, 06 Jan 2021 12:54:43 -0800 (PST) MIME-Version: 1.0 References: <20201214185352.252477-1-lance.richardson@broadcom.com> In-Reply-To: From: Lance Richardson Date: Wed, 6 Jan 2021 15:54:32 -0500 Message-ID: To: Ferruh Yigit Cc: Lance Richardson , Ajit Khaparde , Somnath Kotur , Venkat Duvvuru , dev@dpdk.org, stable@dpdk.org Content-Type: text/plain; charset="UTF-8" Subject: Re: [dpdk-dev] [PATCH] net/bnxt: limit per-poll Rx representor pkts 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" On Wed, Jan 6, 2021 at 4:27 AM Ferruh Yigit wrote: > > On 12/14/2020 6:53 PM, Lance Richardson wrote: > > Limit number of representor packets transferred per poll > > to requested burst size. > > > > Hi Lance, > > Can you please describe the impact of the change? Since it has a fixes line, it > seems it is fixing something but it is not clear what is fixed. > Hi Ferruh, How does this look: Without some limit on the number of packets transferred from the hw ring to the representor ring per burst receive call, an entire ring's worth of packets can be transferred. This can break assumptions about ring indices (index on return could be identical to the index on entry, which is assumed to mean that no packets were processed), and can result in representor packets being dropped unnecessarily due to representor ring overflow. Fix by limiting the number of representor packets transferred per poll to requested burst size. Thanks, Lance