Jing, Thanks for your assistance. The experiment that you have built should allow you to observe the bug. In [5], I would expect that queue 0 receives roughly 1/4 of the packets that you sending, assuming the input packets have varied IP addresses. Can you measure what % of packets are actually being received in this single queue setup (after first running a 4-queue setup)?
When trying to running with only one RX queue, the fm10k retains the same RSS hash function and redirection table that was configured from a previous run. As a result, some packets are still being directed to other receive queues. I have confirmed this by polling the queue specific stats, which I retrieved via rte_eth_xstats_get(). Looking at fm10k_dev_rss_configure(), one should see that there is no modification of fm10k registers when nb_rx_queues == 1. As far as I can tell, this is the reason that only a certain partition of packets are being receive in a single queue setup (after first running a multi-queue configuration). I am unable to access my development environment today, but if you need, I can later craft a patch to l3fwd that shows the measurement of packets received at each queue. Thanks, Mike > On Mar 24, 2016, at 2:40 AM, Chen, Jing D <jing.d.chen at intel.com> wrote: > > Hi, Frasca, > > > >> -----Original Message----- >> From: Michael Frasca [mailto:michael.frasca at oracle.com >> <mailto:michael.frasca at oracle.com>] >> Sent: Wednesday, March 23, 2016 9:43 PM >> To: Chen, Jing D >> Cc: dev at dpdk.org <mailto:dev at dpdk.org> >> Subject: Re: [PATCH] fm10k: conditionally disable RSS during device >> initialization >> >> Hi Jing, >> >> I ran into this issue while trying to run experiments with different RSS >> configurations (no RSS being one cases). It is not clear to me that setting >> this >> register to zero is the best way to disable RSS. >> >> After digging further, I have a theory that I'm having this issues because >> I've >> only attached my DPDK application to SR-IOV ports. In >> fm10k_dev_dglort_map_configure(), I see that 'RSS Length' is set for the >> DGLORT >> decoder. However, it appears that this is only invoked for physical >> functions. >> >> Could this be my problem? Is it required that I bind to the physical function >> if I want to properly manipulate RSS? >> >> Thanks, >> Mike >> > I don't know exactly what problem you ran into. I think we needn't worry > about > those DGLORT setting when using VF device. > > I've followed steps to use SRIOV device with RSS enabled and disabled, both > are worked well from my side after applying your patch. Below is my setup. > > 1. PF with Linux driver "fm10k-next_0.19.3". > 2. DPDK with latest code from master branch, apply your patch. > 3. Use 1 VF device created by kernel driver. > 4. use l3fwd with " ./examples/l3fwd/build/l3fwd -c fc -n 4 -- -p 0x1 > --config="(0,0,2),(0,1,2),(0,2,3),(0,3,3)"" > with RSS enabled. After sending packets, I can see all 4 queues received > packets. > 5. use l3fwd with " ./examples/l3fwd/build/l3fwd -c fc -n 4 -- -p 0x1 > --config="(0,0,2)"" > with RSS disabled. After sending packets, I can see queue 0 received > packets. > > Can you explain what actual problem is? > We can talk offline.
