+ Xiaolong I think we can merge them to dpdk-next-net-intel early since 19.11 cycle is started.
> -----Original Message----- > From: Gavin Hu (Arm Technology China) [mailto:[email protected]] > Sent: Wednesday, August 14, 2019 11:20 AM > To: Zhang, Qi Z <[email protected]>; Richardson, Bruce > <[email protected]>; Ananyev, Konstantin > <[email protected]> > Cc: [email protected]; Honnappa Nagarahalli > <[email protected]>; Phil Yang (Arm Technology China) > <[email protected]>; Ruifeng Wang (Arm Technology China) > <[email protected]> > Subject: RE: i40e vPMD fix out of order Rx read issue > > Hi Qi, > > > -----Original Message----- > > From: Zhang, Qi Z <[email protected]> > > Sent: Saturday, July 27, 2019 9:33 AM > > To: Gavin Hu (Arm Technology China) <[email protected]>; Richardson, > > Bruce <[email protected]>; Ananyev, Konstantin > > <[email protected]> > > Cc: [email protected]; Honnappa Nagarahalli > > <[email protected]>; Phil Yang (Arm Technology China) > > <[email protected]>; Ruifeng Wang (Arm Technology China) > > <[email protected]> > > Subject: RE: i40e vPMD fix out of order Rx read issue > > > > > > > > > -----Original Message----- > > > From: Gavin Hu (Arm Technology China) [mailto:[email protected]] > > > Sent: Friday, July 26, 2019 6:01 PM > > > To: Zhang, Qi Z <[email protected]>; Richardson, Bruce > > > <[email protected]>; Ananyev, Konstantin > > > <[email protected]> > > > Cc: [email protected]; Honnappa Nagarahalli > > > <[email protected]>; Phil Yang (Arm Technology China) > > > <[email protected]>; Ruifeng Wang (Arm Technology China) > > > <[email protected]> > > > Subject: RE: i40e vPMD fix out of order Rx read issue > > > > > > Hi Qi, > > > > > > Thanks for your explanation! > > > I did some testing and found the barriers caused a big drop in > > > RFC2544 NDR performance on aarch64, how about it on X86? > > For x86, I think we don't have performance drop, the memory barrier > > just change the compiler's behavior to avoid generate out of order > > read instructions, and x86 guarantee no out of read execution, so it > > does not add new instructions that cost CPU cycles. > > > > > Is it possible to count DD bits in a way of surviving across the > > > out-of-order descriptors reading? > > > > I think it is possible, but this will impact performance on x86, but > > for aarch64, you can try out to see if that benefit and do proper > > optimization on related vPMD implementation. > The patches for aarch64 are in community review, and performances gain > were measured both for ixgbe and i40e vPMD. Very appreciate if you can > further review and comment. > Here are the patch links: > IXGBE vPMD: > http://patches.dpdk.org/patch/57649/ > http://patches.dpdk.org/patch/57650/ > I40e vPMD: > http://patches.dpdk.org/cover/57651/ > http://patches.dpdk.org/patch/57652/ > > > > > > Best Regards, > > > Gavin > > > > > > > -----Original Message----- > > > > From: Zhang, Qi Z <[email protected]> > > > > Sent: Thursday, July 25, 2019 8:11 PM > > > > To: Gavin Hu (Arm Technology China) <[email protected]>; > > > > Richardson, Bruce <[email protected]>; Ananyev, > > > > Konstantin <[email protected]> > > > > Cc: [email protected]; Honnappa Nagarahalli > > > > <[email protected]>; Phil Yang (Arm Technology China) > > > > <[email protected]> > > > > Subject: RE: i40e vPMD fix out of order Rx read issue > > > > > > > > Hi Gavin: > > > > > > > > in vPMD, we read 4 or 8 packets as batch, we count DD bits for > > > > packet received, but not check the if they are continues or not, > > > > we assume it should always be 1000, 1100, 1110, 1111 ....(take > > > > batch size is 4 as > > > > example) while the out of order read instruction generated by > > > > compiler will cause driver to get un-continues DD bits, like 1011, > > > > the descriptor on the hole actually is invalid since when it is > > > > read , descriptor is not write back yet, but we still process this > > > > as 1110, it cause > > an > > > corrupted mbuf returned. > > > > > > > > hope this is helpful. > > > > > > > > Regards > > > > Qi > > > > > > > > > -----Original Message----- > > > > > From: Gavin Hu (Arm Technology China) [mailto:[email protected]] > > > > > Sent: Thursday, July 25, 2019 5:57 PM > > > > > To: Zhang, Qi Z <[email protected]>; Richardson, Bruce > > > > > <[email protected]>; Ananyev, Konstantin > > > > > <[email protected]> > > > > > Cc: [email protected]; Honnappa Nagarahalli > > > > > <[email protected]>; Phil Yang (Arm Technology China) > > > > > <[email protected]> > > > > > Subject: i40e vPMD fix out of order Rx read issue > > > > > > > > > > Hi Qi, > > > > > > > > > > I am working on optimizing the i40e vPMD on aarch64 and I see > > > > > this patch relevant. > > > > > Could you illuminate what issue this patch was fixing? > > > > > I understand the PMD works at the driver layer, for delivery of > > > > > L2 > > packets. > > > > > It does not own the responsibility to keep order(the > > > > > responsibility lies with > > > > the > > > > > protocol stack, like TCP)? > > > > > > > > > > http://patches.dpdk.org/patch/16665/ > > > > > > > > > > Best regards, > > > > > Gavin > > > > > > > > > > IMPORTANT NOTICE: The contents of this email and any attachments > > > > > are confidential and may also be privileged. If you are not the > > > > > intended recipient, please notify the sender immediately and do > > > > > not disclose the contents to any other person, use it for any > > > > > purpose, or store or copy the information in any medium. Thank you. > > > IMPORTANT NOTICE: The contents of this email and any attachments are > > > confidential and may also be privileged. If you are not the intended > > recipient, > > > please notify the sender immediately and do not disclose the > > > contents to > > any > > > other person, use it for any purpose, or store or copy the > > > information in any medium. Thank you. > IMPORTANT NOTICE: The contents of this email and any attachments are > confidential and may also be privileged. If you are not the intended > recipient, > please notify the sender immediately and do not disclose the contents to any > other person, use it for any purpose, or store or copy the information in any > medium. Thank you.
