usb driver(DPC) has been scheduled on only one CPU RRS feed

  • Question

  • Hi:

    We are testing the USB3.0 performance of our usb driver(usb2ser.sys), which use the DPC. We found some strange phenomenon:

    • When we start testing our driver on sereral specific computers, we found that the OS becomes very slow. We have analysed the xperf log from these computers and found that the usb2ser.sys has been scheduled on only one CPU(CPU0) even though this CPU was already very busy.
    • When we testing our driver on other computers, the OS works normal and the xperf log shows that usb2ser.sys has been scheduled on four CPUs.
    • The kernel revision on the specific computers and the normal computers are the same(6.1.7601 service Pack 1 Build 7601)

    We supposed that there may be some software or hardware configuration caused this issue, can you please kindly share with us? Thanks very much

    Wednesday, January 10, 2018 8:34 AM