From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id 07A15A09EE for ; Sat, 12 Dec 2020 01:45:33 +0100 (CET) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 5B5FEBC84; Sat, 12 Dec 2020 01:45:32 +0100 (CET) Received: from wh10.alp1.flow.ch (wh10.alp1.flow.ch [185.119.84.194]) by dpdk.org (Postfix) with ESMTP id D455AAC9C for ; Sat, 12 Dec 2020 01:45:30 +0100 (CET) Received: from [::1] (port=58720 helo=wh10.alp1.flow.ch) by wh10.alp1.flow.ch with esmtpa (Exim 4.92) (envelope-from ) id 1knt2N-00HZ0H-5G; Sat, 12 Dec 2020 01:45:27 +0100 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Date: Sat, 12 Dec 2020 01:45:23 +0100 From: Alex Kiselev To: "Singh, Jasvinder" Cc: users@dpdk.org, "Dumitrescu, Cristian" , "Dharmappa, Savinay" In-Reply-To: <85944DCD-F0D5-4F64-9E8C-68D1428491B8@intel.com> References: <7909ed9ded69f36b262ff151244c8b0d@therouter.net> , <85944DCD-F0D5-4F64-9E8C-68D1428491B8@intel.com> Message-ID: <4ed02c4280efcfe2bf9e6c51803f807b@therouter.net> X-Sender: alex@therouter.net User-Agent: Roundcube Webmail/1.3.8 X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - wh10.alp1.flow.ch X-AntiAbuse: Original Domain - dpdk.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - therouter.net X-Get-Message-Sender-Via: wh10.alp1.flow.ch: authenticated_id: alex@therouter.net X-Authenticated-Sender: wh10.alp1.flow.ch: alex@therouter.net X-Source: X-Source-Args: X-Source-Dir: Subject: Re: [dpdk-users] scheduler issue X-BeenThere: users@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK usage discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: users-bounces@dpdk.org Sender: "users" On 2020-12-12 01:20, Singh, Jasvinder wrote: >> On 11 Dec 2020, at 23:37, Alex Kiselev wrote: > >> On 2020-12-11 23:55, Singh, Jasvinder wrote: >> On 11 Dec 2020, at 22:27, Alex Kiselev wrote: > >>> On 2020-12-11 23:06, Singh, Jasvinder wrote: > >> On 11 Dec 2020, at 21:29, Alex Kiselev wrote: > >> On 2020-12-08 14:24, Singh, Jasvinder wrote: > >> > >>> [JS] now, returning to 1 mbps pipes situation, try reducing tc >> period > >>> first at subport and then at pipe level, if that help in getting >> even > >>> traffic across low bandwidth pipes. > >> reducing subport tc from 10 to 5 period also solved the problem >> with 1 > >> Mbit/s pipes. > >> so, my second problem has been solved, > >> but the first one with some of low bandwidth pipes stop >> transmitting still > >> remains. > >> I see, try removing "pkt_len <= pipe_tc_ov_credits" condition in >> the > >> grinder_credits_check() code for oversubscription case, instead use > >> this pkt_len <= pipe_tc_credits + pipe_tc_ov_credits; > >> if I do what you suggest, I will get this code > >> enough_credits = (pkt_len <= subport_tb_credits) && > >> (pkt_len <= subport_tc_credits) && > >> (pkt_len <= pipe_tb_credits) && > >> (pkt_len <= pipe_tc_credits) && > >> (pkt_len <= pipe_tc_credits + pipe_tc_ov_credits); > >> And this doesn't make sense since if condition pkt_len <= >> pipe_tc_credits is true > >> then condition (pkt_len <= pipe_tc_credits + pipe_tc_ov_credits) is >> also always true. > >> [JS] my suggestion is to remove“pkt_len <= pipe_tc_credits“, >> “ pkt_len > >> <= pipe_tc_ov_credits”and use only “pkt_len <= pipe_tc_credits >> + > >> pipe_tc_ov_credits“ > >> While keeping tc_ov flag on. > >> Your suggestion just turns off TC_OV feature. > >>> I don't see your point. > >>> This new suggestion will also effectively turn off the TC_OV >>> feature since > >>> the only effect of enabling TC_OV is adding additional condition > >>> pkt_len <= pipe_tc_ov_credits > >>> which doesn't allow a pipe to spend more resources than it should. > >>> And in the case of support congestion a pipe should spent less >>> than %100 of pipe's maximum rate. > >>> And you suggest to allow pipe to spend 100% of it's rate plus some >>> extra. > >>> I guess effect of this would even more unfair support's bandwidth >>> distibution. > >>> Btw, a pipe might stop transmitting even when there is no >>> congestion at a subport. > >> Although I didn’t try this solution but the idea here is - in a > >> particular round, of pkt_len is less than pipe_tc_credits( which is >> a > >> constant value each time) but greater than pipe_tc_ov_credits, then >> it > >> might hit the situation when no packet will be scheduled from the >> pipe > >> even though there are fixed credits greater than packet size is > >> available. > > But that is a perfectly normal situation and that's exactly the idea > behind TC_OV. > It means a pipe should wait for the next subport->tc_ov_period_id > when pipe_tc_ov_credits will be reset to a new value > > But here it’s not guaranteed that new value of pipe_tc_ov_credits > will be sufficient for low bandwidth pipe to send their packets as > each time pipe_tc_ov_credits is freshly computed. > >> pipe->tc_ov_credits = subport->tc_ov_wm * params->tc_ov_weight; >> >> which allows the pipe to continue transmitting. > > No that won’t happen if new tc_ov_credits value is again less than > pkt_len and will hit deadlock. new tc_ov_credits can't not be less than subport->tc_ov_wm_min, and tc_ov_wm_min is equal to port->mtu. all my scheduler ports configured with mtu 1522. etherdev ports also uses the same mtu, therefore there should be no packets bigger that 1522. Maybe I should increase port's MTU? to 1540? > >> And it could not cause a permanent pipe stop which is what I am >> facing. > >>> In fairness, pipe should send the as much as packets which >> >>> consumes pipe_tc_credits, regardless of extra pipe_tc_ov_credits >>> which >> >>> is extra on top of pipe_tc_credits. >> >> I think it's quite the opposite. That's why after I reduced the >> support tc_period >> I got much more fairness. Since reducing subport tc_period also >> reduce the tc_ov_wm_max value. >> s->tc_ov_wm_max = rte_sched_time_ms_to_bytes(params->tc_period, >> port->pipe_tc3_rate_max) >> as a result a pipe transmits less bytes in one round. so pipe >> rotation inside a grinder >> happens much more often and a pipe can't monopolise resources. >> >> in other sos implementation this is called "quantum". > > Yes, so reducing tc period makes the case when all pipes ( high n low > bandwidth) gets lower values of tc_ov_credits values which allow > lesser transmission from higher bw pipes and leave bandwidth for low > bw pipes. So, here is the thing- Either tune tc period to a value > which prevent high bw pipe hogging most of bw or makes changes in the > code, where oversubscription add extra credits on top of guaranteed. > > One question, don’t your low bw pipes have higher priority traffic > tc0, tc1, tc2 . Packets from those tc must be going out. Isn’t this > the case ? well, it would be the case after I find out what's going on. Right now I am using a tos2tc map configured in such a way that all ipv4 packets with any TOS values goes into TC3. > >>> > >>> > >>> > >>>>> rcv 0 rx rate 7324160 nb pkts 5722 > >>>>> rcv 1 rx rate 7281920 nb pkts 5689 > >>>>> rcv 2 rx rate 7226880 nb pkts 5646 > >>>>> rcv 3 rx rate 7124480 nb pkts 5566 > >>>>> rcv 4 rx rate 7324160 nb pkts 5722 > >>>>> rcv 5 rx rate 7271680 nb pkts 5681 > >>>>> rcv 6 rx rate 7188480 nb pkts 5616 > >>>>> rcv 7 rx rate 7150080 nb pkts 5586 > >>>>> rcv 8 rx rate 7328000 nb pkts 5725 > >>>>> rcv 9 rx rate 7249920 nb pkts 5664 > >>>>> rcv 10 rx rate 7188480 nb pkts 5616 rcv 11 rx rate 7179520 nb >> pkts > >>>>> 5609 rcv 12 rx rate 7324160 nb pkts 5722 rcv 13 rx rate >> 7208960 nb > >>>>> pkts 5632 rcv 14 rx rate 7152640 nb pkts 5588 rcv 15 rx rate > >>>>> 7127040 nb pkts 5568 rcv 16 rx rate 7303680 nb pkts 5706 .... > >>>>> rcv 587 rx rate 2406400 nb pkts 1880 rcv 588 rx rate 2406400 nb >> pkts > >>>>> 1880 rcv 589 rx rate 2406400 nb pkts 1880 rcv 590 rx rate >> 2406400 nb > >>>>> pkts 1880 rcv 591 rx rate 2406400 nb pkts 1880 rcv 592 rx rate > >>>>> 2398720 nb pkts 1874 rcv 593 rx rate 2400000 nb pkts 1875 rcv >> 594 rx > >>>>> rate 2400000 nb pkts 1875 rcv 595 rx rate 2400000 nb pkts 1875 >> rcv > >>>>> 596 rx rate 2401280 nb pkts 1876 rcv 597 rx rate 2401280 nb >> pkts > >>>>> 1876 rcv 598 rx rate 2401280 nb pkts 1876 rcv 599 rx rate >> 2402560 nb > >>>>> pkts 1877 rx rate sum 3156416000 > >>>> > >>>> > >>>> > >>>>>>> ... despite that there is _NO_ congestion... > >>>>>>> congestion at the subport or pipe. > >>>>>>>> And the subport !! doesn't use about 42 mbit/s of available > >>>>>>>> bandwidth. > >>>>>>>> The only difference is those test configurations is TC of > >>>>>>>> generated traffic. > >>>>>>>> Test 1 uses TC 1 while test 2 uses TC 3 (which is use TC_OV > >>>>>>>> function). > >>>>>>>> So, enabling TC_OV changes the results dramatically. > >>>>>>>> ## > >>>>>>>> ## test1 > >>>>>>>> ## > >>>>>>>> hqos add profile 7 rate 2 M size 1000000 tc period 40 > >>>>>>>> # qos test port > >>>>>>>> hqos add port 1 rate 10 G mtu 1522 frame overhead 24 queue >> sizes > >>>>>>>> 64 64 64 64 > >>>>>>>> hqos add port 1 subport 0 rate 300 M size 1000000 tc period >> 10 > >>>>>>>> hqos add port 1 subport 0 pipes 2000 profile 7 hqos add port >> 1 > >>>>>>>> subport 0 pipes 200 profile 23 hqos set port 1 lcore 3 port >> 1 > >>>>>>>> subport rate 300 M number of tx flows 300 generator tx rate >> 1M TC > >>>>>>>> 1 ... > >>>>>>>> rcv 284 rx rate 995840 nb pkts 778 rcv 285 rx rate 995840 >> nb > >>>>>>>> pkts 778 rcv 286 rx rate 995840 nb pkts 778 rcv 287 rx rate > >>>>>>>> 995840 nb pkts 778 rcv 288 rx rate 995840 nb pkts 778 rcv >> 289 > >>>>>>>> rx rate 995840 nb pkts 778 rcv 290 rx rate 995840 nb pkts >> 778 > >>>>>>>> rcv 291 rx rate 995840 nb pkts 778 rcv 292 rx rate 995840 >> nb > >>>>>>>> pkts 778 rcv 293 rx rate 995840 nb pkts 778 rcv 294 rx rate > >>>>>>>> 995840 nb pkts 778 ... > >>>>>>>> sum pipe's rx rate is 298 494 720 OK. > >>>>>>>> The subport rate is equally distributed to 300 pipes. > >>>>>>>> ## > >>>>>>>> ## test 2 > >>>>>>>> ## > >>>>>>>> hqos add profile 7 rate 2 M size 1000000 tc period 40 > >>>>>>>> # qos test port > >>>>>>>> hqos add port 1 rate 10 G mtu 1522 frame overhead 24 queue >> sizes > >>>>>>>> 64 64 64 64 > >>>>>>>> hqos add port 1 subport 0 rate 300 M size 1000000 tc period >> 10 > >>>>>>>> hqos add port 1 subport 0 pipes 2000 profile 7 hqos add port >> 1 > >>>>>>>> subport 0 pipes 200 profile 23 hqos set port 1 lcore 3 port >> 1 > >>>>>>>> subport rate 300 M number of tx flows 300 generator tx rate >> 1M TC > >>>>>>>> 3 > >>>>>>>> h5 ~ # rcli sh qos rcv > >>>>>>>> rcv 0 rx rate 875520 nb pkts 684 > >>>>>>>> rcv 1 rx rate 856320 nb pkts 669 > >>>>>>>> rcv 2 rx rate 849920 nb pkts 664 > >>>>>>>> rcv 3 rx rate 853760 nb pkts 667 > >>>>>>>> rcv 4 rx rate 867840 nb pkts 678 > >>>>>>>> rcv 5 rx rate 844800 nb pkts 660 > >>>>>>>> rcv 6 rx rate 852480 nb pkts 666 > >>>>>>>> rcv 7 rx rate 855040 nb pkts 668 > >>>>>>>> rcv 8 rx rate 865280 nb pkts 676 > >>>>>>>> rcv 9 rx rate 846080 nb pkts 661 > >>>>>>>> rcv 10 rx rate 858880 nb pkts 671 rcv 11 rx rate 870400 >> nb > >>>>>>>> pkts 680 rcv 12 rx rate 864000 nb pkts 675 rcv 13 rx rate > >>>>>>>> 852480 nb pkts 666 rcv 14 rx rate 855040 nb pkts 668 rcv >> 15 > >>>>>>>> rx rate 857600 nb pkts 670 rcv 16 rx rate 864000 nb pkts >> 675 > >>>>>>>> rcv 17 rx rate 866560 nb pkts 677 rcv 18 rx rate 865280 >> nb > >>>>>>>> pkts 676 rcv 19 rx rate 858880 nb pkts 671 rcv 20 rx rate > >>>>>>>> 856320 nb pkts 669 rcv 21 rx rate 864000 nb pkts 675 rcv >> 22 > >>>>>>>> rx rate 869120 nb pkts 679 rcv 23 rx rate 856320 nb pkts >> 669 > >>>>>>>> rcv 24 rx rate 862720 nb pkts 674 rcv 25 rx rate 865280 >> nb > >>>>>>>> pkts 676 rcv 26 rx rate 867840 nb pkts 678 rcv 27 rx rate > >>>>>>>> 870400 nb pkts 680 rcv 28 rx rate 860160 nb pkts 672 rcv >> 29 > >>>>>>>> rx rate 870400 nb pkts 680 rcv 30 rx rate 869120 nb pkts >> 679 > >>>>>>>> rcv 31 rx rate 870400 nb pkts 680 rcv 32 rx rate 858880 >> nb > >>>>>>>> pkts 671 rcv 33 rx rate 858880 nb pkts 671 rcv 34 rx rate > >>>>>>>> 852480 nb pkts 666 rcv 35 rx rate 874240 nb pkts 683 rcv >> 36 > >>>>>>>> rx rate 855040 nb pkts 668 rcv 37 rx rate 853760 nb pkts >> 667 > >>>>>>>> rcv 38 rx rate 869120 nb pkts 679 rcv 39 rx rate 885760 >> nb > >>>>>>>> pkts 692 rcv 40 rx rate 861440 nb pkts 673 rcv 41 rx rate > >>>>>>>> 852480 nb pkts 666 rcv 42 rx rate 871680 nb pkts 681 ... > >>>>>>>> ... > >>>>>>>> rcv 288 rx rate 766720 nb pkts 599 rcv 289 rx rate 766720 >> nb > >>>>>>>> pkts 599 rcv 290 rx rate 766720 nb pkts 599 rcv 291 rx rate > >>>>>>>> 766720 nb pkts 599 rcv 292 rx rate 762880 nb pkts 596 rcv >> 293 > >>>>>>>> rx rate 762880 nb pkts 596 rcv 294 rx rate 762880 nb pkts >> 596 > >>>>>>>> rcv 295 rx rate 760320 nb pkts 594 rcv 296 rx rate 604160 >> nb > >>>>>>>> pkts 472 rcv 297 rx rate 604160 nb pkts 472 rcv 298 rx rate > >>>>>>>> 604160 nb pkts 472 rcv 299 rx rate 604160 nb pkts 472 rx >> rate > >>>>>>>> sum 258839040 FAILED. > >>>>>>>> The subport rate is distributed NOT equally between 300 >> pipes. > >>>>>>>> Some subport bandwith (about 42) is not being used!