Windows 10: interrupt affinity, system handles interrupts only on core0

I have everything in msi/msi-x mode, except usb. From measuring dpc in latencymon, i have still 400k dpc calls on core 0, while other 7 cores gets 500-7000 for each, which is disappointing.

And setting in regedit interrupt affinity doesn't help, because hardware/drivers can override that setting. It is really strange, that hardware/drivers/windows wouldn't allocate multicore for handling interrupts: my pc isn't that old i have i7 3700k chipset b75m, which isn't best but still... Interrupts should be spread on all cores, instead being handled only on core 0. It is really like something from 2005.

I am positive i have set it under right device in regedit and i entered under Affinity Policy: "DevicePolicy" and put value 3 in decimal. Or i tried put there IrqPolicyAllProcessorsInMachine instead devicepolicy. Because i am unsure if i have to put there either this or that. But again drivers/hardware can override this setting, so it hasn't necessarily have to work.
https://technet.microsoft.com/en-us/ff547969(v=vs.96)

Still i would expect hardware and drivers should handle this and use multicore for interrupts today times. I am getting new pc, so i will test it on that and hopefully it will be fine. But this doesn't make sense...

:)

 

interrupts being handled only on 2/8 cpu cores

I have all my devices set in msi/msi-x mode, so they should utilize multicore. Yet latencymon shows only 2 of my 8 cores are handling interrupts, which is strange. I even tried set DevicePolicy 5 under interrupt management/affinity policy for my gpu and it had no effect. And don't think latencymon shows wrong information, because it is professional program. Could be tho. Is there any windows setting, where i can set, how much of my cores i can reserve for interrupt management ? Didn't google anything except this, which is what i was talking about https://docs.microsoft.com/en-us/win...y-and-priority

EDIT: hahah it was something as simple like that only 2 cores were checked by default*Biggrin

 

Help with Hardware Interrupts

To use Krview, ignore any driver that is part of Windows or that is for the CPU idle thread.
inteppm is for the CPU idle thread, ignore it.
hal and ntkrnlpa are part of Windows, ignore them.
ati2mtag is the first one on the list that is elevated and relevant.
Find out what hardware interrupt it uses and then any device that shares this interrupt could be the problem. It might not be ati2mtag.
If its the video driver, can you use another card?
Putting the computer to sleep might reset things.

 

strange interrupts

is there no way to check who's signaling the interrupts?