On 2025/1/3 00:01, Edward Cree wrote:
> On 02/01/2025 11:23, Haifeng Xu wrote:
>> We want to make full use of cpu resources to receive packets. So
>> we enable 63 rx queues. But we found the rate of interrupt growth
>> on cpu 0~15 is faster than other cpus(almost twice).
> ...
>> I am confused that why ixgbe NIC can dispatch the packets
>> to the rx queues that not specified in RSS configuration.
>
> Hypothesis: it isn't doing so, RX is only happening on cpus (and
> queues) 0-15, but the other CPUs are still sending traffic and
> thus getting TX completion interrupts from their TX queues.
> `ethtool -S` output has per-queue traffic stats which should
> confirm this.
>
I use ethtool -S to check the rx_queus stats and here is the result.
According to the below stats, all cpus have new packets received.
cpu t1(bytes) t2(bytes) delta(bytes)
0 154155550267550 154156433828875 883561325
1 148748566285840 148749509346247 943060407
2 148874911191685 148875798038140 886846455
3 152483460327704 152484251468998 791141294
4 147790981836915 147791775847804 794010889
5 146047892285722 146048778285682 885999960
6 142880516825921 142881213804363 696978442
7 152016735168735 152017707542774 972374039
8 146019936404393 146020739070311 802665918
9 147448522715540 147449258018186 735302646
10 145865736299432 145866601503106 865203674
11 149548527982122 149549289026453 761044331
12 146848384328236 146849303547769 919219533
13 152942139118542 152942769029253 629910711
14 150884661854828 150885556866976 895012148
15 149222733506734 149223510491115 776984381
16 34150226069524 34150375855113 149785589
17 34115700500819 34115914271025 213770206
18 33906215129998 33906448044501 232914503
19 33983812095357 33983986258546 174163189
20 34156349675011 34156565159083 215484072
21 33574293379024 33574490695725 197316701
22 33438129453422 33438297911151 168457729
23 32967454521585 32967612494711 157973126
24 33507443427266 33507604828468 161401202
25 33413275870121 33413433901940 158031819
26 33852322542796 33852527061150 204518354
27 33131162685385 33131330621474 167936089
28 33407661780251 33407823112381 161332130
29 34256799173845 34256944837757 145663912
30 33814458585183 33814623673528 165088345
31 33848638714862 33848775218038 136503176
32 18683932398308 18684069540891 137142583
33 19454524281229 19454647908293 123627064
34 19717744365436 19717900618222 156252786
35 20295086765202 20295245869666 159104464
36 20501853066588 20502000738936 147672348
37 20954631043374 20954797204375 166161001
38 21102911073326 21103062510369 151437043
39 21376404644179 21376515307288 110663109
40 20935812784743 20935983891491 171106748
41 20721278456831 20721435955715 157498884
42 21268291801465 21268425244578 133443113
43 21661413672829 21661629019091 215346262
44 21696437732484 21696568800049 131067565
45 21027869000890 21028020401214 151400324
46 21707137252644 21707293761990 156509346
47 20655623913790 20655740452889 116539099
48 32692002128477 32692138244468 136115991
49 33548445851486 33548569927672 124076186
50 33197264968787 33197448645817 183677030
51 33379544010500 33379746565576 202555076
52 33503579011721 33503722596159 143584438
53 33145734550468 33145892305819 157755351
54 33422692741858 33422844156764 151414906
55 32750945531107 32751131302251 185771144
56 33404955373530 33405157766253 202392723
57 33701185654471 33701313174725 127520254
58 33014531699810 33014700058409 168358599
59 32948906758429 32949151147605 244389176
60 33470813725985 33470993164755 179438770
61 33803771479735 33803971758441 200278706
62 33509751180818 33509926649969 175469151
Thanks!
> (But Eric is right that if you _want_ RX to use every CPU you
> should just change the indirection table.)
