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 3333D45972 for ; Fri, 13 Sep 2024 01:09:53 +0200 (CEST) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id C99424025E; Fri, 13 Sep 2024 01:09:52 +0200 (CEST) Received: from mail-pl1-f178.google.com (mail-pl1-f178.google.com [209.85.214.178]) by mails.dpdk.org (Postfix) with ESMTP id B9D1440156 for ; Fri, 13 Sep 2024 01:09:50 +0200 (CEST) Received: by mail-pl1-f178.google.com with SMTP id d9443c01a7336-207115e3056so15375615ad.2 for ; Thu, 12 Sep 2024 16:09:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20230601.gappssmtp.com; s=20230601; t=1726182590; x=1726787390; darn=dpdk.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:from:to:cc:subject:date :message-id:reply-to; bh=xbAjC+5KISs4mYorqcnj0w8u7R87JLWPWhcDjo2870k=; b=xI/9PGKY87aEZ3Ez5Jlpz0YNPAE9HROXkuUC4NhywL5TZlSF8noyQZt+DMXOfk5SFQ MOPNg7y29rhbKhiaVeTZTVpLBEP44rML1iR4fRSbg9XVonStksqxs0+H30/A4NzClNu9 mFs+m79Z0CQMp7/f/58dYHA/N5UG0yv7Ay1cDzQgxH3Z6XJHVJzCYr5LzQ5Y5VbGwrDj eq4UBr+30bFdPY6XzY/Y3qA9JIJy0aHavLygH8Og6JdpG45TGDcmNXpFdgOmGr5kckq3 8wrJgDDbhgc5rjKN6K7J1GPy4N3/gFojRdVLpsxe2zV+f/RGjsYQkVOenFqwRoAsfiAC S72w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1726182590; x=1726787390; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=xbAjC+5KISs4mYorqcnj0w8u7R87JLWPWhcDjo2870k=; b=dbdHWrJqLylL870SvxcE7hzpuqlX67smNuQdTvri5ek55e/fmQKn+HAbKGIPBPN8Ex HfYOXHgrj2WAUXF1Wi/0mLiPrsqvdCXMue92l3+UDtByaSpZiQ45iyX7OxGYMd71buB1 xho8LnPEOTlYU81IyByFR8hxiEawj+5v9ZtF7OULvWUadVPlFXfztGRad8SuV68/tbo7 havi+M/h1GCqFb37WmqUcg+F36KhwHc26MPL83pmR8qFltA04nOYDP9d+iiTpkBw/Ps3 /s8jIEgac0o5hdTH5L2pPHfnztYcDOJ1UB/l40RIstVw4HD4L/WfD24JnRKI1m/FVQwZ g4cg== X-Forwarded-Encrypted: i=1; AJvYcCUZ8wP4wrnUA1AGNWExvtJeTq2118Ux+Tjfi/gJCkXIpQjz2rz8KTUY6Sx9l/HhgAPOY54ITg==@dpdk.org X-Gm-Message-State: AOJu0Yz7tpMcGAaKJctTsvIjzkIlBHhcHdlRbTUJbNfP8cysmjpZsCwc 0eRWXtFE54DjQiTXqG3cXi0Z+D9WBvgoZBmHP7bbbizW3i0SjCpPfgvzr1FeTgU= X-Google-Smtp-Source: AGHT+IHVzyqoUPs/5gWD9ljlkM9ArVsaxYindVqhBWYTEkrzKYLdb7Xj3QSehUSIhHPt7LjReljwlg== X-Received: by 2002:a17:902:e5d1:b0:206:c2e3:68ef with SMTP id d9443c01a7336-2076e3c2048mr56771215ad.22.1726182589783; Thu, 12 Sep 2024 16:09:49 -0700 (PDT) Received: from hermes.local (204-195-96-226.wavecable.com. [204.195.96.226]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-2076af252e2sm18901915ad.6.2024.09.12.16.09.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 12 Sep 2024 16:09:49 -0700 (PDT) Date: Thu, 12 Sep 2024 16:09:48 -0700 From: Stephen Hemminger To: Nandini Rangaswamy Cc: Long Li , "users@dpdk.org" Subject: Re: Netvsc vs Failsafe Performance Message-ID: <20240912160948.3714f01d@hermes.local> In-Reply-To: References: <20240903170350.7e663864@hermes.local> <20240904154246.1c5bbb58@hermes.local> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-BeenThere: users@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK usage discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: users-bounces@dpdk.org On Thu, 12 Sep 2024 13:47:37 -0700 Nandini Rangaswamy wrote: > Thanks for your response Long Li. > I see with netvsc the maximum number of Tx descriptors is restricted to > 4096 whereas the number of Rx descriptors is restricted to 8192. > But, for failsafe PMD , we see that both the number of Txd and Rxd is > restricted to 8192. > How is netvsc PMD giving the same performance as failsafe PMD ? > > Regards I think the limits there were somewhat arbitrary chose with netvsc. Don't remember a hard reason that would block larger sizes. Having really big rings won't help performance (i.e BufferBloat) and could a lot of memory consumption. When all heavy data traffic goes through the VF and that ring is different. Only DoS attacks should be impacted by rx/tx descriptor limits in the netvsc device. The linux driver actually has much smaller buffer.