2017-12-15 19:10 GMT+08:00 Bruno Wolff III <bruno@xxxxxxxx>: > On Fri, Dec 15, 2017 at 10:04:32 +0800, > weiping zhang <zwp10758@xxxxxxxxx> wrote: >> >> I just want to know WARN_ON WHAT in device_add_disk, >> if bdi_register_owner return error code, it may fail at any step of >> following: > > > Was that output in the original boot log? I didn't see anything there that > had the string WARN_ON. The first log was from a Fedora kernel. The second Sorry to let you confuse, WARN_ON means we catch log as following: WARNING: CPU: 3 PID: 3486 at block/genhd.c:680 device_add_disk+0x3d9/0x460 > from a kernel I built. I used a Fedora config though. The config was > probably from one of their nodebug kernels, I could build another one using > a config from a debug kernel. Would that likely provide what you are looking > for? Yes, please help reproduce this issue include my debug patch. Reproduce means we can see WARN_ON in device_add_disk caused by failure of bdi_register_owner. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>