Using this script yesterday it worked without problem for almost two hours, the amount of available time I hade before had to sleep. Today it does not work, randomly a few seconds in between there is a delay of around 15 milliseconds, not able to figure out why.
I did some experiments and might have happened I did something that made it work. Guess other option is some random resource allocation and I was unlucky today. Nicklas Karlsson sön 2026-09-20 klockan 11:01 +0200 skrev Nicklas SB Karlsson: > No have have not seen this script, thanks. With modification to use correct > Ethernet interface it will most > certainly work. > > Script set IRQ affinity for Ethernet card interrupts. I also moved away other > IRQs from CPU used for Ethernet > interrupts. If I got it correct script also change priority and affinity the > IRQS used fro Ethernet interrupts, I > did not do this and expect it is an improvement. > > Note rx-usecs and tx-usecs is set to zero. If i remember manual correct this > mean blocking call and this might be > a problem if a packet is dropped never arrive but there is also a timeout on > function call to recv(...). Pretty > sure I used 1 µs for these parameters. > > > I also used ISOLcpu and a few other parameters. > > > Nicklas Karlsson > > > sön 2026-09-20 klockan 06:38 +0200 skrev [email protected]: > > Did you try Hannes script? > > https://github.com/hdiethelm/xenomai4-linuxcnc/issues/2#issuecomment- > > 5345811568 > > > > I350 must be combined. > > > > "---------- Původní zpráva ---------- > > Od: Nicklas SB Karlsson <[email protected]> > > Datum: 20.09.2026 02:26:23 > > Předmět: Re: [Emc-users] Ethernet send packets jitter > > > > Yes isolate the last CPU and pin the Ethernet IRQd to that CPU and pin other > > interrupts seems to do the trick. > > Running for six minutes worst delay of received packet is slightly above 153 > > µs. > > > > If some other interrupt prevented receiving of ethernet frame it also agree > > with latency on receive I measured > > earlier. > > > > This is on the I350 card there I previously had delays of up to around 15 > > milliseconds followed by a burst of > > receives. If I could get the hardware time trigger to sending of frames then > > transmission would be perfect, > > equally spaced exactly at the intended, this is a small detail I do not > > however think make any difference in > > practice. > > > > Regard Nicklas Karlsson > > > > > > tor 2026-09-17 klockan 07:28 -0700 skrev Peter Wallace: > > > On Thu, 17 Sep 2026, andy pugh wrote: > > > > > > > On Wed, 16 Sept 2026 at 21:20, Nicklas SB Karlsson wrote: > > > > > > > > > Running Linuxcnc and send receive Ethernet jitter is small for most > > packets but sometimes there is delay of well > > > > > above on millisecond, running for maybe a minute or so worst case is > > between 6...7 milliseconds. > > > > > > > > Maybe you need to disable IRQ coalescing? It's mentioned briefly in > > > > the hm2_eth docs, but also might be relevant to EtherCAT. > > > > https://linuxcnc.org/docs/stable/html/man/man9/hm2_eth.9.html > > > > > > > > (It's at least a google-able phrase for further investigation) > > > > > > At least for hm2_eth, basic Network latency improvement methods are: > > > > > > > > > On Intel (and some less common others like broadcom), disable IRQ > > coalescing > > > > > > On Realtek, install the DKMS driver (the stock Linux driver has multi-ms > > > random latencies) > > > > > > On all, use isolcpus (or whatever the newer scheme is called) to isolate > > the > > > last CPU, and then pin the Ethernet IRQ to that CPU. > > > > > > Use the latest kernel (I have a test system that always got random > > timeouts, > > > say once a day, with 6.x kernels, this was totally fixed with a 7.X kernel > > > > > > > > > > > > > > -- > > > > atp > > > > "A motorcycle is a bicycle with a pandemonium attachment and is > > > > designed for the especial use of mechanical geniuses, daredevils and > > > > lunatics." > > > > ? George Fitch, Atlanta Constitution Newspaper, 1912 > > > > > > > > > > > > _______________________________________________ > > > > Emc-users mailing list > > > > [email protected] > > > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > > > Peter Wallace > > > Mesa Electronics > > > > > > > > > _______________________________________________ > > > Emc-users mailing list > > > [email protected] > > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > > > _______________________________________________ > > Emc-users mailing list > > [email protected] > > https://lists.sourceforge.net/lists/listinfo/emc-users > > " > > _______________________________________________ > > Emc-users mailing list > > [email protected] > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
