Comment 20 for bug 1488426

Peter Curtis (pdcurtis) wrote :

I have tried the test patch provided by Mathias Nyman in http://linux-kernel.2935.n7.nabble.com/TESTPATCH-v2-xhci-fix-usb2-resume-timing-and-races-tc1250796.html#a1256745 and rebuilt a Wily 4.2 kernel and that has prevented High CPU usage of kworker/ksoftirqd under all the circumstances I have tried. Note this is marked as a TESTPATCH and Mathias Nyman mentions his intention is to " do some minor cleanups and add it to the queue ". At best it will be in the 4.4 kernel and then available for backports but it good to know that there is a solution in hand.

@acelan Is there any way for you to also push the Mathias Nyman patch into the ubuntu kernel, assuming it also solves your original problem. Then normal users can just use an updated ubuntu kernel to get rid of this issue. As it is a timing and race problem it may well turn out to have a much wider impact than current reports show, in particular as it seems to affect Skylake machines.