CLAIMINTERFACE / RELEASEINTERFACE ioctl cause high load on newer kernels with usb_endpoint device node support
Franz Sirl <[email protected]>
| Newsgroups | gmane.linux.usb.devel |
|---|---|
| Message-ID | <[email protected]> |
Hi, we have an application that shares an USB device by protecting bulk read/writes with CLAIMINTERFACE/RELEASEINTERFACE ioctl calls. That worked fine until recently when device nodes for the endpoints where introduced. What happens is that our quick switching between the applications causes a flood of udev events for the add/remove of the endpoint device nodes. This initially lead to a very unresponsive machine where udevd consumed all of the CPU time. In the meantime I mitigated the effect by adding some explicit udev ignore rules for the endpoints. But still each started instance of our application adds about 5% udevd CPU load on a 2GHz Celeron. So, is there a way to turn off the endpoint device node creation/deletion via a udev config or a kernel ioctl? Franz ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ [email protected] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel