On Fri, Jan 12, 2018 at 06:26:02PM +0100, Laurent Dufour wrote: > There is a deadlock when a CPU is doing a speculative page fault and > another one is calling do_unmap(). > > The deadlock occurred because the speculative path try to spinlock the > pte while the interrupt are disabled. When the other CPU in the > unmap's path has locked the pte then is waiting for all the CPU to > invalidate the TLB. As the CPU doing the speculative fault have the > interrupt disable it can't invalidate the TLB, and can't get the lock. > > Since we are in a speculative path, we can race with other mm action. > So let assume that the lock may not get acquired and fail the > speculative page fault.
It seems like you introduced this bug in the previous patch, and now you're fixing it in this patch? Why not merge the two?
