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 CF296A0C46; Wed, 9 Jun 2021 14:46:44 +0200 (CEST) Received: from [217.70.189.124] (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 6C8A040E3C; Wed, 9 Jun 2021 14:46:44 +0200 (CEST) Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by mails.dpdk.org (Postfix) with ESMTP id 6B2284003C for ; Wed, 9 Jun 2021 14:46:42 +0200 (CEST) IronPort-SDR: lSutvoTc2FdwkM6t0rkl8YYwi8tINJKo79cQDvUSLDfYJA9zNuVMuTMpa2f9lmA7+KalxDwMNp 2+1ci0peC6sA== X-IronPort-AV: E=McAfee;i="6200,9189,10009"; a="205027065" X-IronPort-AV: E=Sophos;i="5.83,260,1616482800"; d="scan'208";a="205027065" Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Jun 2021 05:46:41 -0700 IronPort-SDR: BKjZ8SwL8F/Wa1id76StKSUAa5BCJgC3YJnRu55Ry6Bcfy8FimHcw7+rbiiaIEOP6wigjGW3jz hy1ZFiT+Bghw== X-IronPort-AV: E=Sophos;i="5.83,260,1616482800"; d="scan'208";a="419268222" Received: from bricha3-mobl.ger.corp.intel.com ([10.252.10.226]) by orsmga002-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-SHA; 09 Jun 2021 05:46:38 -0700 Date: Wed, 9 Jun 2021 13:46:35 +0100 From: Bruce Richardson To: David Marchand Cc: Shanmugasundaram M , dev , Olivier Matz , Guillaume Gaudonville , Jean-Mickael Guerin Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Subject: Re: [dpdk-dev] Reg 6Wind fastpath DPDK 18.11.1 virtual memory allocation ( 54.5GB of anonymous mapping) 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, Jun 09, 2021 at 02:28:04PM +0200, David Marchand wrote: > On Wed, Jun 9, 2021 at 2:02 PM Shanmugasundaram M wrote: > > We are using 6Wind fastpath(fp-rte) which is using DPDK version 18.11.1. > > We are seeing 65.5G(preallocated during startup) of virtual memory for > > fp-rte on a 32GB machine, 10G of that was huge pages (5000 mappings of 2M.) > > > > We found 4 strange anon (4K size) segments totaling 54.5G (16+16+16+6.5). > > Note: we changed / customized memory CONFIG_RTE_MAX_MEMSEG_PER_LIST=24576 > > and default value of CONFIG_RTE_MAX_MEMSEG_LISTS=64 used. > > Kindly let us know > > 1. Why are allocating 54.5 GB anonymous mapping > > 2. When will we use it ? > > This is likely pre-reserved virtual memory from the DPDK allocator. > This virtual memory won't probably never be used. > There may not be actually any memory backing this, since DPDK will reserve huge amounts of virtual address space without actually using it. So those GB's you see in the virtual memory may be completely unused, the addresses are just reserved to ensure that if memory does need to be mapped into the process, we have an appropriate contiguous address block to put it in. > But you'd better ask 6WIND guys as they maintain their own DPDK downstream. > > Copying a few guys. > > -- > David Marchand >