> -----Original Message----- > From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Bruce Richardson > Sent: Wednesday, February 18, 2015 1:32 PM > To: Tetsuya Mukawa > Cc: dev at dpdk.org > Subject: Re: [dpdk-dev] [RFC PATCH] lib/librte_ethdev: Expand port identifier > > On Wed, Feb 18, 2015 at 12:30:07PM +0000, Bruce Richardson wrote: > > 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 <mukawa at igel.co.jp> > > > --- > > > 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?
Not real application but simple example of setup: 4 Niantic x 2 ports x 64 VF = 512 port id I don't know what would be the real need/advantage of such setup (bonding?) but you see, in theory it is already insufficient. > > > > Regards, > > /Bruce > > > > Resending with correct email addr for Neil. > > /Bruce
