From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bruce Richardson Subject: Re: [RFC PATCH] lib/librte_ethdev: Expand port identifier Date: Wed, 18 Feb 2015 12:30:07 +0000 Message-ID: <20150218123006.GB5960@bricha3-MOBL3> References: <1424257369-19130-1-git-send-email-mukawa@igel.co.jp> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: dev-VfR2kkLFssw@public.gmane.org, nhroman-2XuSBdqkA4R54TAoqtyWWQ@public.gmane.org To: Tetsuya Mukawa Return-path: Content-Disposition: inline In-Reply-To: <1424257369-19130-1-git-send-email-mukawa-AlSX/UN32fvPDbFq/vQRIQ@public.gmane.org> List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces-VfR2kkLFssw@public.gmane.org Sender: "dev" On Wed, Feb 18, 2015 at 08:02:49PM +0900, Tetsuya Mukawa wrote: > Currently uint8_t is used for port identifier. This patch changes it, > and use uint16_t as port identifier. > This patch only changes ethdev library. ABI of the library will be > kept even after applying it. > > Also, this patch involves following fixes. > - Use "port_id" as variable name instead of "port". > > > Signed-off-by: Tetsuya Mukawa > --- > lib/librte_ether/rte_ethdev.c | 212 +- > lib/librte_ether/rte_ethdev_internal.h | 3672 ++++++++++++++++++++++++++++++++ > 2 files changed, 3778 insertions(+), 106 deletions(-) > create mode 100644 lib/librte_ether/rte_ethdev_internal.h > I'm not sure I follow why we need a new header file for this. Also, thinking about this change, a more fundamental problem is going to be the mbuf structure, which stores a port id inside it in an 8-bit value. Upgrading that to a 16-bit value requires some thought, and verification to ensure any adjustment of fields does not lead to serious performance issues. Therefore, I suggest we leave the port id values as 8-bits until such time as we need greater than 255 port values in a real-world use case. Out of interest - anyone have a DPDK app where they use >16 port id values? If so, how high does the port id value get? Regards, /Bruce