On Thursday 11 April 2013 20:59:05 Ming Lei wrote: > On Thu, Apr 11, 2013 at 8:28 PM, Oliver Neukum <oliver@xxxxxxxxxx> wrote: > > On Thursday 11 April 2013 20:11:13 Ming Lei wrote: > >> On Thu, Apr 11, 2013 at 7:14 PM, Oliver Neukum <oliver@xxxxxxxxxx> wrote: > >> > > >> > Sorry, I misunderstood. > >> > >> No problem, :-) > >> > >> > > >> > Task A Task B queue > >> > > >> > queue work > >> > request a reset > >> > allocate memory and block > >> > cancel the work > >> > shit happened > >> > >> If I understand the case correctly, the above deadlock can be avoided > >> by canceling rx/tx URBs at the end of pre_reset() or usbnet_disconnect(), > > > > No. cancel_work_sync() must wait for the work. The work will not finish. > > The work will complete when memory is reclaimed, and the rx/tx path is > still working, so memory reclaim can continue and the deadlock may not > be caused, may it? Only if the memory allocation goes to the same interface. If the blocking interface is storage, something bad happens (data loss not deadlock) Regards Oliver -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
