> -----Original Message----- > From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Olivier MATZ > Sent: Wednesday, December 3, 2014 10:42 PM > To: Ananyev, Konstantin; Liu, Jijiang; dev at dpdk.org > Subject: Re: [dpdk-dev] [PATCH v5 2/3] mbuf:add three TX ol_flags and repalce > PKT_TX_VXLAN_CKSUM > > Hi Konstantin, > > On 12/03/2014 01:59 PM, Ananyev, Konstantin wrote: > >> I still think having a flag IPV4 + another flag IP_CHECKSUM is not > >> appropriate. > > > > Sorry, didn't get you here. > > Are you talking about our discussion should PKT_TX_IP_CKSUM and > PKT_TX_IPV4 be mutually exclusive or not? > > Yes > > >> I though Konstantin agreed on other flags, but I may have > >> misunderstood: > >> > >> http://dpdk.org/ml/archives/dev/2014-November/009070.html > > > > In that mail, I was talking about my suggestion to make PKT_TX_IP_CKSUM, > PKT_TX_IPV4 and PKT_TX_IPV6 to occupy 2 bits. > > Something like: > > #define PKT_TX_IP_CKSUM (1 << X) > > #define PKT_TX_IPV6 (2 << X) > > #define PKT_TX_IPV4 (3 << X) > > > > "Even better, if we can squeeze these 3 flags into 2 bits. > > Would save us 2 bits, plus might be handy, as in the PMD you can do: > > > > switch (ol_flags & TX_L3_MASK) { > > case TX_IPV4: > > ... > > break; > > case TX_IPV6: > > ... > > break; > > case TX_IP_CKSUM: > > ... > > break; > > }" > > > > As you pointed out, it will break backward compatibility. > > I agreed with that and self-NACKed it. > > ok, so we are back between: > > 1/ (Jijiang's patch) > PKT_TX_IP_CKSUM /* packet is IPv4, and we want hw cksum */ > PKT_TX_IPV6 /* packet is IPv6 */ > PKT_TX_IPV4 /* packet is IPv4, and we don't want hw cksum */ > > with PKT_TX_IP_CKSUM and PKT_TX_IPV4 exclusive > > and > > 2/ > PKT_TX_IP_CKSUM /* we want hw IP cksum */ > PKT_TX_IPV6 /* packet is IPv6 */ > PKT_TX_IPV4 /* packet is IPv4 */ There is another bit flag named 'PKT_TX_IPV4_CSUM' which uses the same bit of 'PKT_TX_IP_CSUM'. It is for identifying if ipv4 hardware checksum offload is needed or not. It seems that we do not need 'PKT_TX_IPV6_CSUM'. 'PKT_TX_IPV4' and 'PKT_TX_IPV6' just indicates its packet type, and I guess other features should not be contained in it, according to its name.
So here I got the option 3: PKT_TX_IPV4_CKSUM /* we want hw IPv4 cksum */ PKT_TX_IPV6 /* packet is IPv6 */ PKT_TX_IPV4 /* packet is IPv4 */ > > with PKT_TX_IP_CKSUM implies PKT_TX_IPV4 > > > Solution 2/ looks better from a user point of view. Anyone else has an > opinion? > > Regards, > Olivier Regards, Helin
