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 4BC934391F; Sun, 21 Jan 2024 18:07:37 +0100 (CET) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id C711C402AB; Sun, 21 Jan 2024 18:07:36 +0100 (CET) Received: from mail-oa1-f53.google.com (mail-oa1-f53.google.com [209.85.160.53]) by mails.dpdk.org (Postfix) with ESMTP id 008C240150 for ; Sun, 21 Jan 2024 18:07:34 +0100 (CET) Received: by mail-oa1-f53.google.com with SMTP id 586e51a60fabf-21086556f32so1770308fac.3 for ; Sun, 21 Jan 2024 09:07:34 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20230601.gappssmtp.com; s=20230601; t=1705856854; x=1706461654; 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=9OB5cb4nXoHgtSV91s8fS3eqT2OY5XGj+cT2Joq4+0Y=; b=OBa3D2MS7nTH0Qh+N5tgYiSHSQ5vgADGhdRu/M6wIXvZ1uai0m/Gilk3zXrzMlPu/u z1ve+PWfk3wujUiTUqLniAStucLIqETz3IvlpPx53vZ712qAVrFcxA/HBgEqzf0Xq6Eq aZDQkjOBEB+AXC6Jk1F9+dA7ZBVSFgbybz5otOPcSdOLNg1aoJrZIMSJg8YeTPR5y0// FCEGCN1F5kuagNS9eQvGM7bs4kjJJJ7ueKIBuxxpAAXKzkJ/8WpkrKusRDXuBSYZFjvm zajXTxSvKXb7WjKXbQ54PlULLVBBmQtN3rx4Y3riyaHgwvZR4igVdH/3VH8JEpQGSHkL fsXg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1705856854; x=1706461654; 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=9OB5cb4nXoHgtSV91s8fS3eqT2OY5XGj+cT2Joq4+0Y=; b=GDsrRb5JGepOnJk3bpiEr5+ujbGNbG547hZmWhLajSeJ4Y4DSk+E4he7Pggy4G//6X jatPfneSUjvcWYsIlGqYuG0fkfJfbhfBrVnJTMlIwcZQKBJNueswuX93ReadjbomDIe7 blmPIq5BEZnk8t1030uraCMogEtb8oZ9pGn3S25oyUYyImlN5Oa78iixPYJr/UULLn+Z x7d8o9r5ALMmje7okuLemQmkw8hqIZoqryLx5ADejqQ//3j4xC4dxjNzB7wkalmBpJVV zkZ3xzgSgTib2KCQXHQND9MdHaDKIPijJlKM3rDlyIfpoWuO4dnzuYVwbmcRGhPDkMfc dwow== X-Gm-Message-State: AOJu0YyZqBzo2txMneQSctdCXYPgRXq7DUE/vWxOlt4Dd9rCuNM6EjYa rQIp5wPBb0LL3tpumXKKTTS9yTN555CRXhGwsTVIJIDJkt04SqnQmkAQGqaeJTYAQSJzVPTRr0d XUu0= X-Google-Smtp-Source: AGHT+IG26aMJVIt0kDiaYC50BA+ez/kr7OLgVNNdls/5X9cZj/T6AKAxXXHeFRFphlFnINkrEbYc2w== X-Received: by 2002:a05:6358:7302:b0:176:2874:3a2 with SMTP id d2-20020a056358730200b00176287403a2mr2034910rwg.47.1705856853912; Sun, 21 Jan 2024 09:07:33 -0800 (PST) Received: from hermes.local (204-195-123-141.wavecable.com. [204.195.123.141]) by smtp.gmail.com with ESMTPSA id sv4-20020a17090b538400b0028b17832efdsm7821433pjb.39.2024.01.21.09.07.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 21 Jan 2024 09:07:33 -0800 (PST) Date: Sun, 21 Jan 2024 09:07:32 -0800 From: Stephen Hemminger To: Morten =?UTF-8?B?QnLDuHJ1cA==?= Cc: , Subject: Re: [RFC] mbuf: performance optimization Message-ID: <20240121090732.3cf8c5d6@hermes.local> In-Reply-To: <98CBD80474FA8B44BF855DF32C47DC35E9F17D@smartserver.smartshare.dk> References: <98CBD80474FA8B44BF855DF32C47DC35E9F17D@smartserver.smartshare.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable 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 On Sun, 21 Jan 2024 06:32:42 +0100 Morten Br=C3=B8rup wrote: > I suppose that reducing mbuf->nb_segs from 16 to 8 bit is realistic, cons= idering that a maximum size IP packet (64 KB) is unlikely to use more than = 64 plus some segments. Does anyone know of any use case with more than 255 = segments in an mbuf? There is the case of Linux internally using super large IPv6 (and now IPv4)= frames. See RFC 2675 IPv6 jumbograms https://netdevconf.info/0x15/slides/35/BIG%20TCP.pdf