On 07/27/2011 07:06 AM, Giorgos Vasiliadis wrote: > Dear Duyck, > > I found your e-mail in some lists regarding the ixgbe driver > development. The reason I sent you this email, is because I want to > ask you a question about the RSS hash function in intel 88599 cards. > > In my project, I want to have packets of the same flow (both incoming > and outgoing) hashed to the same hardware queue. That means, I want > the hash function to use only the IP header fields (and not the > TCP/UDP). Is that possible with the current driver? > > In 82599_Datasheet_rev_2_0.pdf it is stated that by setting the > IXGBE_MRQC_RSS_FIELD_IPV4 and unsetting the > IXGBE_MRQC_RSS_FIELD_IPV4_TCP value, the hash function will use only > the IP header. Is that true? If not, is any way to perform hashing > symmetry? > > Thanks in advance, > > Sincerely yours, > Giorgos Vasiliadis Giorgos,
I would recommend looking at some patches I had submitted as an RFC back in December. http://patchwork.ozlabs.org/patch/76051/ http://patchwork.ozlabs.org/patch/76052/ http://patchwork.ozlabs.org/patch/76053/ What they provided was a framework similar to what you have described. The piece that will likely be of most interest to use is the changes to ixgbe_setup_mrqc that can be found in patch 2 of the 3 above. What it specifically did is reduce the RSS key to a 16 bit repeating value. The advantage of this is that it makes the TX and RX flow hash result the same using the same process. Thanks, Alex ------------------------------------------------------------------------------ Got Input? Slashdot Needs You. Take our quick survey online. Come on, we don't ask for help often. Plus, you'll get a chance to win $100 to spend on ThinkGeek. http://p.sf.net/sfu/slashdot-survey _______________________________________________ E1000-devel mailing list E1000-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/e1000-devel To learn more about Intel® Ethernet, visit http://communities.intel.com/community/wired
