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 E6E2BA09EE for ; Sat, 12 Dec 2020 00:36:40 +0100 (CET) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 2ED70BC84; Sat, 12 Dec 2020 00:36:39 +0100 (CET) Received: from wh10.alp1.flow.ch (wh10.alp1.flow.ch [185.119.84.194]) by dpdk.org (Postfix) with ESMTP id 7A7CDAC9E for ; Sat, 12 Dec 2020 00:36:36 +0100 (CET) Received: from [::1] (port=53066 helo=wh10.alp1.flow.ch) by wh10.alp1.flow.ch with esmtpa (Exim 4.92) (envelope-from ) id 1knrxj-00HOBm-5Q; Sat, 12 Dec 2020 00:36:35 +0100 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Date: Sat, 12 Dec 2020 00:36:35 +0100 From: Alex Kiselev To: "Singh, Jasvinder" Cc: users@dpdk.org, "Dumitrescu, Cristian" , "Dharmappa, Savinay" In-Reply-To: References: <7909ed9ded69f36b262ff151244c8b0d@therouter.net> Message-ID: 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 2020-12-11 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 pipe->tc_ov_credits = subport->tc_ov_wm * params->tc_ov_weight; which allows the pipe to continue transmitting. 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". > > > > >> >>>>>> > >>>>>> > >>>>>> > >>>>>> >>> 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!