Hi Yao, Dave recently fixed bug related to alignment, Are you using latest code?
Also, few days ago i merged new significantly-faster SIMD based ip checksum code[1], you can try that one also... [1] https://git.fd.io/vpp/commit/?id=08bca80 Thanks, -- Damjan > On 29 Jun 2018, at 09:27, Yao, Chengqiang <chengqiang....@intel.com> wrote: > > Hi, > > I have an issue when calculating the checksum of two IP headers with > ip4_header_checksum function. The content of these two IP headers are exactly > the same. The only difference between these 2 IP headers is that, one IP > header’s address is 64 bits aligned, while the other one is not (My test bed > is x86_64). The return value of ip4_header_checksum function for these two IP > headers are different. Anyone knows why? > > I also wrote a simple test code to test this function. The result is as below: > > > [root@localhost vpp_pdcp]# ./test_ip_checksum > > ip header 1: 0x45 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0xfe 0x11 0x0 0x0 0xc0 0xa8 > 0x32 0x48 0xc0 0xa8 0x32 0x47 > > ip header 1 address:0x7fff1b1ba1a0, csum 1:0xcd7 > > ip header 2: 0x45 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0xfe 0x11 0x0 0x0 0xc0 0xa8 > 0x32 0x48 0xc0 0xa8 0x32 0x47 > > ip header 2 address:0x7fff1b1ba171, csum 2:0x1bc8 > > > > Best Regards, > Chengqiang Yao > > -=-=-=-=-=-=-=-=-=-=-=- > Links: You receive all messages sent to this group. > > View/Reply Online (#9737): https://lists.fd.io/g/vpp-dev/message/9737 > <https://lists.fd.io/g/vpp-dev/message/9737> > Mute This Topic: https://lists.fd.io/mt/22892325/675642 > <https://lists.fd.io/mt/22892325/675642> > Group Owner: vpp-dev+ow...@lists.fd.io <mailto:vpp-dev+ow...@lists.fd.io> > Unsubscribe: https://lists.fd.io/g/vpp-dev/unsub > <https://lists.fd.io/g/vpp-dev/unsub> [dmar...@me.com > <mailto:dmar...@me.com>] > -=-=-=-=-=-=-=-=-=-=-=-
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