Hi, > -----Original Message----- > From: Thomas Monjalon [mailto:thomas.monjalon at 6wind.com] > Sent: Thursday, November 13, 2014 4:53 PM > To: Liu, Jijiang > Cc: Zhang, Helin; dev at dpdk.org; Richardson, Bruce > Subject: Re: [dpdk-dev] [PATCH v6 1/9] librte_mbuf:the rte_mbuf structure > changes > > 2014-11-13 03:17, Liu, Jijiang: > > From: Thomas Monjalon [mailto:thomas.monjalon at 6wind.com] > > > 2014-10-23 02:23, Zhang, Helin: > > > > From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Thomas > > > > Monjalon > > > > > 2014-10-21 14:14, Liu, Jijiang: > > > > > > From: Thomas Monjalon [mailto:thomas.monjalon at 6wind.com] > > > > > > > 2014-10-21 16:46, Jijiang Liu: > > > > > > > > + uint16_t packet_type; > > > > > > > > > > > > > > Why not name it "l2_type"? > > > > > > > > 'packet_type' is for storing the hardware identified packet type > > > > upon different layers of protocols (l2, l3, l4, ...). > > > > It is quite useful for user application or middle layer software > > > > stacks, it can know what the packet type is without checking the > > > > packet too > > > much by software. > > > > Actually ixgbe already has packet types (less than 10), which is > > > > transcoded into > > > 'ol_flags'. > > > > For i40e, the packet type can represent about 256 types of packet, > > > > 'ol_flags' does not have enough bits for it anymore. So put the > > > > i40e packet types > > > into mbuf would be better. > > > > Also this field can be used for NON-Intel NICs, I think there must > > > > be the similar concepts of other NICs. And 16 bits 'packet_type' > > > > has severl > > > reserved bits for future and NON-Intel NICs. > > > > > > Thanks Helin, that's the best description of packet_type I've seen so far. > > > It's not so clear in the commit log: > > > http://dpdk.org/browse/dpdk/commit/?id=73b7d59cf4f6faf > > > > > > > > > In datasheet, this term is called packet type(s). > > > > > > > > > > That's exactly the point I want you really understand! > > > > > This is a field in generic mbuf structure, so your datasheet has no > > > > > value > here. > > > > > > > > > > > Personally , I think packet type is more clear what meaning of > > > > > > this field > is . > > > > > > > > > > You cannot add an API field without knowing what will be its generic > meaning. > > > > > Please think about it and describe its scope. > > > > > > I integrated this patch with the VXLAN patchset in the hope that > > > you'll improve the situation afterwards. > > > This is the answer you recently gave to Olivier: > > > http://dpdk.org/ml/archives/dev/2014-November/007599.html > > > " > > > Regarding adding a packet_type in mbuf, we ever had a lot of > > > discussions as follows: > > > http://dpdk.org/ml/archives/dev/2014-October/007027.html > > > http://dpdk.org/ml/archives/dev/2014-September/005240.html > > > http://dpdk.org/ml/archives/dev/2014-September/005241.html > > > http://dpdk.org/ml/archives/dev/2014-September/005274.html > > > " > > > > > > To sum up the situation: > > > - We don't know what are the possible values of packet_type > > > - It's only filled by i40e, while other drivers use ol_flags > > > - There is no special value "unknown" which should be set by drivers > > > not supporting this feature. > > > - Its only usage is to print a decimal value in > > > app/test-pmd/rxonly.c > > > > > > It's now clear that nobody cares about this part of the API. > > > So I'm going to remove packet_type from mbuf. > > > I don't want to keep something that we don't know how to use, that > > > is not consistent across drivers, and that overlap another API part > > > (ol_flags). > > > > The packet type in 40e is very important for user, using packet type > > can help to speed up packet analysis/identification in their > > application, especially tunneling packet format. > > Now I'm working on implementing packet type definition in rte_ethdev.h > > file and translation table in i40e, which is almost done. > > The packet type definition in in rte_ethdev.h file like below. > > /* > > * Ethernet packet type > > */ > > enum rte_eth_ptype { > > /* undefined packet type, means HW can't recognise it */ > > RTE_PTYPE_UNDEF = 0, > > ... > > > > /* IPv4 --> GRE/Teredo/VXLAN --> MAC --> IPv4 */ > > RTE_PTYPE_IPv4_GRENAT_MAC_IPv4FRAG_PAY3, > > RTE_PTYPE_IPv4_GRENAT_MAC_IPv4_PAY3, > > RTE_PTYPE_IPv4_GRENAT_MAC_IPv4_UDP_PAY4, > > RTE_PTYPE_IPv4_GRENAT_MAC_IPv4_TCP_PAY4, > > RTE_PTYPE_IPv4_GRENAT_MAC_IPv4_SCTP_PAY4, > > RTE_PTYPE_IPv4_GRENAT_MAC_IPv4_ICMP_PAY4, > > > > /* IPv4 --> GRE/Teredo/VXLAN --> MAC --> IPv6 */ > > RTE_PTYPE_IPv4_GRENAT_MAC_IPv6FRAG_PAY3 > > RTE_PTYPE_IPv4_GRENAT_MAC_IPv6_PAY3, > > RTE_PTYPE_IPv4_GRENAT_MAC_IPv6_UDP_PAY4, > > RTE_PTYPE_IPv4_GRENAT_MAC_IPv6_TCP_PAY4, > > RTE_PTYPE_IPv4_GRENAT_MAC_IPv6_SCTP_PAY4, > > RTE_PTYPE_IPv4_GRENAT_MAC_IPv6_ICMP_PAY4, > > > > /* IPv4 --> GRE/Teredo/VXLAN --> MAC/VLAN */ > > RTE_PTYPE_IPv4_GRENAT_MACVLAN_PAY3, > > ... > > } > > OK, it seems well abstracted. > I think the last part of these names (PAY3/PAY4) is useless. > > When this patch for API and i40e will be ready? > I'd prefer fixing the API instead of removing it.
If needed, next week, I can send a patch for this. > > Yes, we don't use packet type in many places now, which doesn't mean > > we don't use it in the future (when supporting another tunneling packet). > > > > It is ok for me if you want to remove the packet_type filed in mbuf, > > but we will send a separate patch set for introducing packet type in > > the future, which includes 1g/10/40g PMD changes. > > When the patches for igb/ixgbe will be ready? We need some time to investigate this for igb/ixgbe, probably some example codes and test application codes need to changed. You can assume that it cannot be done in DPDK1.8. So here are my three suggestions: 1. keep packet_type in mbuf and wait for all the igb/ixgb/i40e changes done in DPDK2.0. Now, I don't send a separate patch set for it. 2. keep packet_type in mbuf, I just send i40e patch set for this in DPDK1.8. In DPDK2.0, we will send a patch set for igb/ixgbe. 3. It can be removed now, and we will send a separate patch set for introducing packet type in the future. > Thanks > -- > Thomas
