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 5635E43D5D; Tue, 26 Mar 2024 21:35:11 +0100 (CET) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 2A29F40E6E; Tue, 26 Mar 2024 21:35:11 +0100 (CET) Received: from mail-pl1-f180.google.com (mail-pl1-f180.google.com [209.85.214.180]) by mails.dpdk.org (Postfix) with ESMTP id BDB4340E4A for ; Tue, 26 Mar 2024 21:35:09 +0100 (CET) Received: by mail-pl1-f180.google.com with SMTP id d9443c01a7336-1e0f2798b47so1520915ad.1 for ; Tue, 26 Mar 2024 13:35:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20230601.gappssmtp.com; s=20230601; t=1711485309; x=1712090109; 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=bM5gRitv47DLbK7D5nfE+rB1SviwyvP/KcBQuFJCXdQ=; b=IV3XRnbrCpJGuuZCtFc31FBkpDsZZEfQPxCee3JzZQXBD1Y92wb1ALuQnBIqW+X0ew QfAWW3TZMDWi9iOQtgsNybQzptUdAypvwQbfq04ECjhNswfx9GW17+jCV3lrHgUrqDrR I7E1ZHd+YwZdTpT32RivgGVdnxv/10dtmNskaCCy8P+pvrwEYy2pyyXLf7rUO+JKfKSB lvNgEItXxo6i0U7a9GhF/+p+fDfvD5uQFfGxsTzgiuQZdeFtBO6nCxqTPuXYR/6WdbC4 ngjX6jt7BvNXd+O8O6HeBL6rTpVLi3L3cxqp+MUClfteQ4S6PZCEqni+De2OqQAMo7Vv WeTg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1711485309; x=1712090109; 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=bM5gRitv47DLbK7D5nfE+rB1SviwyvP/KcBQuFJCXdQ=; b=eSegRTgJ32D8/NqrpJ8+Lg70Q9TZNRzff+aSmgp4iRLOf9HKygXXHTZhmjl2SOtVXB Mu78q4wTv8YmgGWIJzXTh4PQJXl0TgjTYPDmNf1XOf+nXxSNYg1vThEfei8uP3Jj29eo ZIXCKAHbs0jczbIMceWcDz3i3LVLKxpTJahq6uRkME3BWJbeMhO8kXG2ta08KuWVtRO6 ZE+ODINPAQNMPsTqTRrFCmK3aQb9fh8I7KK7EIoZUCQnLbe7Ldno75IC2PN3eSBEQDmG PaXAJVlfXQ9peTA56gDghzAnv4LrrQV79PtK0RTkDchOilrwrriZ54jTvopSuqaI9NFo T83Q== X-Forwarded-Encrypted: i=1; AJvYcCUK3Yy24MyFPdx4YKI16i1D7U6b8dtTfxEb04E8sN6yAB4zk2g17DM2/DIsMfsRunsNtZtKJxys/NhTPEs= X-Gm-Message-State: AOJu0YxmDUOdAiSNekMguPjJ92MsoeXojcFNsJe9DLS2L9iR9df9GPDx DePDpMfURrbsAYLtqsmUBIWDyjrJZx9HT+9AsOTMRWWTVu8Z5RZFrvBfXzwhGN0= X-Google-Smtp-Source: AGHT+IHx00CBEEnOqALF1qs6bEnN1vpl9uuq5RCLFEg17lPuQo9/ev+ml67hzkuz1iWXLyINhymEZA== X-Received: by 2002:a17:902:ecd0:b0:1e0:2bce:d7e6 with SMTP id a16-20020a170902ecd000b001e02bced7e6mr3481785plh.32.1711485308670; Tue, 26 Mar 2024 13:35:08 -0700 (PDT) Received: from hermes.local (204-195-123-203.wavecable.com. [204.195.123.203]) by smtp.gmail.com with ESMTPSA id x15-20020a170902ec8f00b001ddda95074fsm7367806plg.11.2024.03.26.13.35.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 26 Mar 2024 13:35:08 -0700 (PDT) Date: Tue, 26 Mar 2024 13:35:06 -0700 From: Stephen Hemminger To: Garrett D'Amore Cc: Morten =?UTF-8?B?QnLDuHJ1cA==?= , dev@dpdk.org, Parthakumar Roy , Bruce Richardson Subject: Re: meson option to customize RTE_PKTMBUF_HEADROOM patch Message-ID: <20240326133506.6d4fb00f@hermes.local> In-Reply-To: References: <20240325102030.46913a06@hermes.local> <98CBD80474FA8B44BF855DF32C47DC35E9F32D@smartserver.smartshare.dk> <98CBD80474FA8B44BF855DF32C47DC35E9F337@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 Tue, 26 Mar 2024 10:43:30 -0700 Garrett D'Amore wrote: > This had occurred to me as well.=C2=A0=C2=A0I think most hardware DMA eng= ines can align on 32-bit boundaries.=C2=A0=C2=A0I've yet to see a device th= at actually requires 64-bit DMA alignment.=C2=A0=C2=A0(But I have only look= ed at a subset=C2=A0=C2=A0of devices, and most of the=C2=A0=C2=A0ones I hav= e looked at are not ones that would be considered 'modern'.) There maybe a PCI transaction performance penalty if not aligned.