Re: Performance comparision / qdisc / no qdisc / queueing linux kernel 4.12
On Fri, Aug 11, 2017 at 4:16 PM, Stephen Hemminger wrote: > Any of the current qdisc that do rate control are single threaded. > Since bandwidth is a shared resource, the qdisc has to acquire a lock > and update cache shared data structures. > > Don't expect HTB or HFSC to be free. > This is a well known problem and there have been several attempts to address it over the years (a long time ago at Google I implemented a horrible hack called "hold queue" that put a parallelized queue in front of HTB. This eliminated the lock contention, but not without side effects). Now there's a new scheduler proposed by some Googlers called Carousel that promises scalable host traffic shaping (https://www.cc.gatech.edu/~amsmti3/files/carousel-sigcomm17.pdf). Looks like they didn't implement a kernel Qdisc, but might be interesting for someone to look into... Tom >> >> 4.13-rc3 have kernel panic when deleting qdisc - will try to get panic trace > > Please do. >
Re: Performance comparision / qdisc / no qdisc / queueing linux kernel 4.12
Any of the current qdisc that do rate control are single threaded. Since bandwidth is a shared resource, the qdisc has to acquire a lock and update cache shared data structures. Don't expect HTB or HFSC to be free. > > 4.13-rc3 have kernel panic when deleting qdisc - will try to get panic trace Please do.
Re: Performance comparision / qdisc / no qdisc / queueing linux kernel 4.12
With 4.13-rc3 have kernel panic when deleting qdisc - will try to get panic trace W dniu 2017-08-05 o 18:38, Paweł Staszewski pisze: Hi Want to send some comparisions about poor performance of kernel when simple queueing is enabled So first - kernel performance for forwarded udp packets generated from pktgen: UDP stream ~10Mpps - random destination from network 172.16.0.0/12 + random udp port Forwarding performance with 8x RSS queues enp216s0f0: 9772859.00 P/s 0.00 P/s 9772859.00 P/s enp216s0f1:0.00 P/s 9772883.00 P/s 9772883.00 P/s -- total: 9772863.00 P/s 9772886.00 P/s 19545750.00 P/s mpstat -P ALL 1 10 Average: CPU%usr %nice%sys %iowait%irq %soft %steal %guest %gnice %idle Average: all0.000.000.000.000.00 11.89 0.00 0.000.00 88.11 Average: 00.000.000.000.000.00 0.10 0.00 0.000.00 99.90 Average: 10.000.000.000.000.00 0.00 0.00 0.000.00 100.00 Average: 20.000.000.000.000.00 0.00 0.00 0.000.00 100.00 Average: 30.000.000.000.000.00 0.00 0.00 0.000.00 100.00 Average: 40.000.000.000.000.00 0.00 0.00 0.000.00 100.00 Average: 50.000.000.000.000.00 0.00 0.00 0.000.00 100.00 Average: 60.000.000.000.000.00 0.00 0.00 0.000.00 100.00 Average: 70.000.000.000.000.00 0.00 0.00 0.000.00 100.00 Average: 80.000.000.000.000.00 0.00 0.00 0.000.00 100.00 Average: 90.000.000.000.000.00 0.00 0.00 0.000.00 100.00 Average: 100.000.000.000.000.00 0.00 0.00 0.000.00 100.00 Average: 110.000.000.000.000.00 0.00 0.00 0.000.00 100.00 Average: 120.000.000.000.000.00 0.00 0.00 0.000.00 100.00 Average: 130.000.000.000.000.00 0.00 0.00 0.000.00 100.00 Average: 140.000.000.000.000.00 0.00 0.00 0.000.00 100.00 Average: 150.000.000.000.000.00 0.00 0.00 0.000.00 100.00 Average: 160.000.000.000.000.00 0.00 0.00 0.000.00 100.00 Average: 170.000.000.000.000.00 0.00 0.00 0.000.00 100.00 Average: 180.000.000.000.000.00 0.00 0.00 0.000.00 100.00 Average: 190.000.000.000.000.00 0.00 0.00 0.000.00 100.00 Average: 200.000.000.000.000.00 0.00 0.00 0.000.00 100.00 Average: 210.000.000.000.000.00 0.00 0.00 0.000.00 100.00 Average: 220.000.000.000.000.00 0.00 0.00 0.000.00 100.00 Average: 230.000.000.000.000.00 0.00 0.00 0.000.00 100.00 Average: 240.000.000.000.000.00 0.00 0.00 0.000.00 100.00 Average: 250.000.000.000.000.00 0.00 0.00 0.000.00 100.00 Average: 260.000.000.000.000.00 0.00 0.00 0.000.00 100.00 Average: 270.000.000.000.000.00 0.00 0.00 0.000.00 100.00 Average: 280.000.000.000.000.00 0.00 0.00 0.000.00 100.00 Average: 290.000.000.000.000.00 0.00 0.00 0.000.00 100.00 Average: 300.000.000.000.000.00 0.00 0.00 0.000.00 100.00 Average: 310.000.000.000.000.00 0.00 0.00 0.000.00 100.00 Average: 320.000.000.000.000.00 0.00 0.00 0.000.00 100.00 Average: 330.000.000.000.000.00 0.00 0.00 0.000.00 100.00 Average: 340.000.000.000.000.00 0.00 0.00 0.000.00 100.00 Average: 350.000.000.000.000.00 0.00 0.00 0.000.00 100.00 Average: 360.000.000.000.000.00 0.00 0.00 0.000.00 100.00 Average: 370.000.000.000.000.00 0.00 0.00 0.000.00 100.00 Average: 380.000.000.000.000.00 0.00 0.00 0.000.00 100.00 Average: 390.000.000.000.000.00 0.00 0.00 0.000.00 100.00 Average: 400.000.000.000.000.00 0.00 0.00 0.000.00 100.00 Average: 410.000.000.000.000.00 0.00 0.00 0.000.00 100.00 Average: 420.000.000.000.000.00 0.00 0.00 0.000.00 100.00 Average: 430.000.000.000.000.00 0.00 0.00