Unexpected realtime delay and genserkins

I try, but

dj@debian22:~$ sudo ethtool -C eth0 rx-usecs 0
[sudo] password for dj:
Cannot get device coalesce settings: Operation not supported

How correct this option?

Thanks!

That probably means that eth0 is not a Intel MAC (so the driver does not have that option nor is it needed)
What does dmesg say about your Ethernet chip?

dmesg | grep -i eth

[ 1.557538] r8169 Gigabit Ethernet driver 2.3LK-NAPI loaded
[ 1.562748] r8169 0000:01:00.0: eth0: RTL8168b/8111b at 0xf8246000, 4c:cc:6a:b0:6d:90, XID 14100800 IRQ 137
[ 1.562750] r8169 0000:01:00.0: eth0: jumbo features [frames: 4080 bytes, tx checksumming: ko]
[ 17.171030] Bluetooth: BNEP (Ethernet Emulation) ver 1.3
[ 18.901063] r8169 0000:01:00.0: eth0: link down
[ 18.901091] r8169 0000:01:00.0: eth0: link down
[ 18.901161] ADDRCONF(NETDEV_UP): eth0: link is not ready
[ 22.229996] r8169 0000:01:00.0: eth0: link up
[ 22.230048] ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
[ 32.365302] eth0: no IPv6 routers present

Right, so that's a Realtek MAC so it doesn't have (or need) the IRQ coalesce option set

Also your hal file has the wrong thread order(order of addf's), it should be
7i92 read
everything else
7i92 write

What actual PC hardware are you running?

Is that a laptop you are using?

I changed the order, but no effect

After homing:
motion.servo.last-period = 3500000
servo-thread.tmax = 1120000

When error appears:
motion.servo.last-period = 3500000
servo-thread.tmax = 14000000

My PC is desktop: Pentium Core Duo, chipset H110