Hi.
Sorry for late response.

Looking at your perf data, I see functions like "dp_packet_batch_size"
consuming ~0.5 - 0.7 % of time. Are you building with all compiler
optimizations disabled? Otherwise where should be no such symbols in
perf report. They should be completely inlined.

Best regards, Ilya Maximets.

On 27.06.2018 04:48, Shahaji Bhosle wrote:
> Hi Ilya,
> Just wanted to check if you found anything interesting. Or anything we can 
> try. Thanks, Shahaji
> 
> On Wed, Jun 20, 2018 at 9:01 AM, Shahaji Bhosle <[email protected] 
> <mailto:[email protected]>> wrote:
> 
>     Thanks Ilya, 
>      Sorry for the confusion with the number, we used to get some different 
> numbers on both ports so were recording it per port. You have to compare it 
> with the two port number....
> 
>               CPU mask        Mpps
>     17.11 testpmd     6 queue 0xfe    21.5 + 21.5
>     OvS 2.9+DPDK17.11 6 queue 0xfe    15.5 + 15.5
>     16.11 testpmd     6 queue 0xfe    21.5 + 21.5
>     OvS 2.7+DPDK16.11 6 queue 0xfe    17.4+17.4
> 
> 
>     Thanks, Shahaji
> 
>     On Wed, Jun 20, 2018 at 8:34 AM, Ilya Maximets <[email protected] 
> <mailto:[email protected]>> wrote:
> 
>         Ok, I'll look at the data later.
> 
>         But your testpmd results are much lower than OVS results. 21.5Mpps 
> for testpmd
>         versus 33.8Mpps for OVS. OVS should work slower than testpmd, because 
> it performs
>         a lot of parsing and processing while testpmd does not.
>         You probably tested testpmd in deifferent environment or allocated 
> less amount
>         of resources for PMD htreads. Could you please recheck?
> 
>         What is your OVS configuration (pmd-cpu-mask, n_rxqs etc.)?
>         And what is your testpmd command-line?
> 
>         On 20.06.2018 14:54, Shahaji Bhosle wrote:
>         > Thanks Ilya,
>         > Attaching the two perf reports...We did run testpmd on its own, 
> there were no red flags there. In some of the cases like flowgen 17.11 
> performs much better than 16.11, but for the macswap case, the numbers are 
> below. Let me know if you cannot see the attached perf reports. I can just 
> cut and paste them in the email if attachment does not work. Sorry I am not 
> sure I can post these on any outside servers. Let me know
>         > Thanks, Shahaji
>         > 
>         > *DPDK on Maia (macswap)*      *Rings*         *Mpps*  
> *Cycles/Packet*
>         > 17.11 testpmd                 6 queue         21.5 + 21.5     60
>         >                               1 queue         10.4+10.4       14
>         > 16.11 testpmd                 6 queue         21.5 + 21.5     60
>         >                               1 queue         10.4+10.4       14
>         > 
>         > 
>         > On Wed, Jun 20, 2018 at 4:52 AM, Ilya Maximets 
> <[email protected] <mailto:[email protected]> 
> <mailto:[email protected] <mailto:[email protected]>>> wrote:
>         >
>         >     Looking at your perf stats I see following:
>         >
>         >     OVS 2.7:
>         >
>         >       ??.??% - dp_netdev_process_rxq_port
>         >       |-- 93.36% - dp_netdev_input
>         >       |-- ??.??% - netdev_rxq_recv
>         >
>         >     OVS 2.9:
>         >
>         >       99.69% - dp_netdev_process_rxq_port
>         >       |-- 79.45% - dp_netdev_input
>         >       |-- 11.26% - dp_netdev_pmd_flush_output_packets
>         >       |-- ??.??% - netdev_rxq_recv
>         >
>         >     Could you please fill the missed (??.??) values?
>         >     This data I got from the picture attached to the previous mail, 
> but pictures
>         >     are still not allowed in mail-list (i.e. stripped). It'll be 
> good if you can
>         >     upload your raw data to some external resource and post the 
> link here.
>         >
>         >     Anyway, from the data I have, I can see that total sum of time 
> spent in
>         >     "dp_netdev_input" and "dp_netdev_pmd_flush_output_packets" for 
> 2.9 is 90.71%,
>         >     which is less then 93.36% spent for 2.7. This means that 
> processing + sending
>         >     become even faster or remains with the approximately same 
> performance.
>         >     We definitely need all the missed values to be sure, but it 
> seems that the
>         >     "netdev_rxq_recv()" could be the issue.
>         >
>         >     To check if DPDK itself causes the performance regression, I'd 
> ask you
>         >     to check pure PHY-PHY test with testpmd app from DPDK 16.11 and 
> DPDK 17.11.
>         >     Maybe it's the performance issue with bnxt driver that you're 
> using.
>         >     There was too many changes in that driver:
>         >
>         >       30 files changed, 17189 insertions(+), 3358 deletions(-)
>         >
>         >     Best regards, Ilya Maximets.
>         >
>         >     On 20.06.2018 01:18, Shahaji Bhosle wrote:
>         >     > Hi Ilya,
>         >     > This issue is a release blocker for us, just wanted to check 
> check if you need more details from us? Anything to expedite or root cause 
> the problem we can help 
>         >     > Please let us know 
>         >     > Thanks Shahaji 
>         >     >
>         >     > On Mon, Jun 18, 2018 at 10:20 AM Shahaji Bhosle 
> <[email protected] <mailto:[email protected]> 
> <mailto:[email protected] <mailto:[email protected]>> 
> <mailto:[email protected] <mailto:[email protected]> 
> <mailto:[email protected] <mailto:[email protected]>>>> 
> wrote:
>         >     > 
>         >     >     Thanks Ilya, I will look at the commit, but not sure now 
> how to tell how much real work is being done, I would have liked polling 
> cycles to be treated as before and not towards packet processing. That does 
> explain, as long as there are packets on the wire we are always 100%, 
> basically cannot tell how efficiently the CPUs are being used.
>         >     >     Thanks, Shahaji
>         >     > 
>         >     >     On Mon, Jun 18, 2018 at 10:07 AM, Ilya Maximets 
> <[email protected] <mailto:[email protected]> 
> <mailto:[email protected] <mailto:[email protected]>> 
> <mailto:[email protected] <mailto:[email protected]> 
> <mailto:[email protected] <mailto:[email protected]>>>> wrote:
>         >     > 
>         >     >         Thanks for the data.
>         >     > 
>         >     >         I have to note additionally that the meaning of 
> "processing cycles"
>         >     >         significantly changed since the following commit:
>         >     > 
>         >     >             commit a2ac666d5265c01661e189caac321d962f54649f
>         >     >             Author: Ciara Loftus <[email protected] 
> <mailto:[email protected]> <mailto:[email protected] 
> <mailto:[email protected]>> <mailto:[email protected] 
> <mailto:[email protected]> <mailto:[email protected] 
> <mailto:[email protected]>>>>
>         >     >             Date:   Mon Feb 20 12:53:00 2017 +0000
>         >     > 
>         >     >                 dpif-netdev: Change definitions of 'idle' & 
> 'processing' cycles
>         >     > 
>         >     >                 Instead of counting all polling cycles as 
> processing cycles, only count
>         >     >                 the cycles where packets were received from 
> the polling.
>         >     > 
>         >     >         This could explain the difference in "PMD Processing 
> Cycles" column,
>         >     >         because successful "POLLING" cycles are now included 
> into "PROCESSING".
>         >     > 
>         >     >         Best regards, Ilya Maximets.
>         >     > 
>         >     >         On 18.06.2018 16:31, Shahaji Bhosle wrote:
>         >     >         > Hi Ilya,
>         >     >         > Thanks for the quick reply, 
>         >     >         > Please find the numbers for our PHY-PHY test, 
> please note that with OVS 2.9.1 + DPDK 17.11 even a 10% of the below numbers 
> will make the OVS 2.9+DPDK17.11 processing cycles to hit 100%, but 2.7 will 
> on our setup never goes above 75% for processing cycles. I am also attaching 
> the perf report between the two code bases and I think the  
> "11.26%--dp_netdev_pmd_flush_output_packets" is causing us to take the 
> performance hit. Out testing is also SRIOV and CPUs are ARM A72 cores. We are 
> happy to run more tests, it is not easy for use to move back to OVS 2.8, but 
> could happy to try more experiments if it helps us narrow down further. 
> Please note we have also tried increasing the tx-flush-interval and it helps 
> a little but still not significant enough. Let us know.
>         >     >         > 
>         >     >         > Thanks, Shahaji 
>         >     >         > 
>         >     >         > 
>         >     >         > *Setup:*
>         >     >         > IXIA<----SFP28--->Port 0 {(PF0)==[OVS+DPDK]==(PF1)} 
> Port 1<-----SFP28---->IXIA
>         >     >         > 
>         >     >         > release/version       config  Test    direction     
>   MPPS    Ixia Line rate (%)      PMD Processing Cycles (%)
>         >     >         > OVS 2.9 + DPDK 17.11  OVS on Maia (PF0--PF1)  No 
> drop port 1 to 2     31.3    85      99.9
>         >     >         >                                                     
>   port 2 to 1     31.3    85      99.9
>         >     >         >                                                     
>   bi      15.5 + 15.5     42      99.9
>         >     >         >                                               
>         >     >         >                                               
>         >     >         > OVS 2.7 + DPDK 16.11  OVS on Maia (PF0--PF1)  No 
> drop port 1 to 2     33.8    90      71
>         >     >         >                                                     
>   port 2 to 1     32.7    88      70
>         >     >         >                                                     
>   bi      17.4+17.4       47      74
>         >     >         > 
>         >     >         > 
>         >     >         > 
>         >     >         > 
>         >     >         > 
>         >     >         > 
>         >     >         > 
>         >     >         > On Mon, Jun 18, 2018 at 4:25 AM, Nitin Katiyar 
> <[email protected] <mailto:[email protected]> 
> <mailto:[email protected] <mailto:[email protected]>> 
> <mailto:[email protected] <mailto:[email protected]> 
> <mailto:[email protected] <mailto:[email protected]>>> 
> <mailto:[email protected] <mailto:[email protected]> 
> <mailto:[email protected] <mailto:[email protected]>> 
> <mailto:[email protected] <mailto:[email protected]> 
> <mailto:[email protected] <mailto:[email protected]>>>>> 
> wrote:
>         >     >         > 
>         >     >         >     Hi,
>         >     >         >     We also experienced degradation from OVS2.6/2.7 
> to OVS2.8.2(with DPDK17.05.02). The drop is more for 64 bytes packet size 
> (~8-10%) even with higher number of flows. I tried OVS 2.8 with DPDK17.11 and 
> it improved for higher packet sizes but 64 bytes size is still the concern.
>         >     >         > 
>         >     >         >     Regards,
>         >     >         >     Nitin
>         >     >         > 
>         >     >         >     -----Original Message-----
>         >     >         >     From: Ilya Maximets 
> [mailto:[email protected] <mailto:[email protected]> 
> <mailto:[email protected] <mailto:[email protected]>> 
> <mailto:[email protected] <mailto:[email protected]> 
> <mailto:[email protected] <mailto:[email protected]>>> 
> <mailto:[email protected] <mailto:[email protected]> 
> <mailto:[email protected] <mailto:[email protected]>> 
> <mailto:[email protected] <mailto:[email protected]> 
> <mailto:[email protected] <mailto:[email protected]>>>>]
>         >     >         >     Sent: Monday, June 18, 2018 1:32 PM
>         >     >         >     To: [email protected] 
> <mailto:[email protected]> <mailto:[email protected] 
> <mailto:[email protected]>> <mailto:[email protected] 
> <mailto:[email protected]> <mailto:[email protected] 
> <mailto:[email protected]>>> <mailto:[email protected] 
> <mailto:[email protected]> <mailto:[email protected] 
> <mailto:[email protected]>> <mailto:[email protected] 
> <mailto:[email protected]> <mailto:[email protected] 
> <mailto:[email protected]>>>>; [email protected] 
> <mailto:[email protected]> <mailto:[email protected] 
> <mailto:[email protected]>> <mailto:[email protected] 
> <mailto:[email protected]> <mailto:[email protected] 
> <mailto:[email protected]>>> <mailto:[email protected] 
> <mailto:[email protected]> <mailto:[email protected] 
> <mailto:[email protected]>>
>         <mailto:[email protected] 
> <mailto:[email protected]> <mailto:[email protected] 
> <mailto:[email protected]>>>>
>         >     >         >     Subject: Re: [ovs-dev] 64Byte packet 
> performance regression on 2.9 from 2.7
>         >     >         >
>         >     >         >     CC: Shahaji Bhosle
>         >     >         >
>         >     >         >     Sorry, missed you in CC list.
>         >     >         >
>         >     >         >     Best regards, Ilya Maximets.
>         >     >         >
>         >     >         >     On 15.06.2018 10:44, Ilya Maximets wrote:
>         >     >         >     >> Hi,
>         >     >         >     >> I just upgraded from OvS 2.7 + DPDK 16.11 to 
> OvS2.9 + DPDK 17.11 and
>         >     >         >     >> running into performance issue with 64 Byte 
> packet rate. One
>         >     >         >     >> interesting thing that I notice that even at 
> very light load from
>         >     >         >     >> IXIA the processing cycles on all the PMD 
> threads run close to 100%
>         >     >         >     >> of the cpu cycle on 2.9 OvS, but on OvS 2.7 
> even under full load the
>         >     >         >     >> processing cycles remain at 75% of the cpu 
> cycles.
>         >     >         >     >>
>         >     >         >     >> Attaching the FlameGraphs of both the 
> versions, the only thing that
>         >     >         >     >> pops out to me is the new way invoking 
> netdev_send() is on 2.9 is
>         >     >         >     >> being invoked via  
> dp_netdev_pmd_flush_output_packets() which seems
>         >     >         >     >> to be adding another ~11% to the whole rx to 
> tx path.
>         >     >         >     >>
>         >     >         >     >> I also did try the tx-flush-interval to 50 
> and more it does seem to
>         >     >         >     >> help, but not significant enough to match 
> the 2.7 performance.
>         >     >         >     >>
>         >     >         >     >>
>         >     >         >     >> Any help or ideas would be really great. 
> Thanks, Shahaji
>         >     >         >     >
>         >     >         >     > Hello, Shahaji.
>         >     >         >     > Could you, please, describe your testing 
> scenario in more details?
>         >     >         >     > Also, mail-list filters attachments, so they 
> are not available. You
>         >     >         >     > need to publish them somewhere else or write 
> in text format inside the letter.
>         >     >         >     >
>         >     >         >     > About the performance itself: Some 
> performance degradation because of
>         >     >         >     > output batching is expected for tests with 
> low number of flows or
>         >     >         >     > simple PHY-PHY tests. It was mainly targeted 
> for cases with relatively
>         >     >         >     > large number of flows, for amortizing of 
> vhost-user penalties
>         >     >         >     > (PHY-VM-PHY, VM-VM cases), OVS bonding cases.
>         >     >         >     >
>         >     >         >     > If your test involves vhost-user ports, then 
> you should also consider
>         >     >         >     > vhost-user performance regression in stable 
> DPDK 17.11 because of
>         >     >         >     > fixes for CVE-2018-1059. Related bug:
>         >     >         >     >       
> https://dpdk.org/tracker/show_bug.cgi?id=48 
> <https://dpdk.org/tracker/show_bug.cgi?id=48> 
> <https://dpdk.org/tracker/show_bug.cgi?id=48 
> <https://dpdk.org/tracker/show_bug.cgi?id=48>> 
> <https://dpdk.org/tracker/show_bug.cgi?id=48 
> <https://dpdk.org/tracker/show_bug.cgi?id=48> 
> <https://dpdk.org/tracker/show_bug.cgi?id=48 
> <https://dpdk.org/tracker/show_bug.cgi?id=48>>>
>         >     >         >     >
>         >     >         >     > It'll be good if you'll be able to test OVS 
> 2.8 + DPDK 17.05. There
>         >     >         >     > was too many changes since 2.7. It'll be hard 
> to track down the root cause.
>         >     >         >     >
>         >     >         >     > Best regards, Ilya Maximets.
>         >     >         >     >
>         >     >         >
>         >     >         >
>         >     >
>         >     >
>         >
>         >
> 
> 
> 
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