On Tue, Aug 03, 2021 at 04:14:38PM +0800, Huang, Ying wrote: > Matthew Wilcox <willy@xxxxxxxxxxxxx> writes: > > But I REALLY REALLY REALLY want a reproducer. Right now, I have a hard > > time believing this, or any of the other races can really happen. > > I think the race is only theoretical too. Firstly, swapoff is a rare > operations in practice; secondly, the race window is really small. So do something to provoke it. Widen the window. Put an msleep(1000) between *pagep = NULL and the call to get_swap_device(). That's assuming that the swapon/swapoff loop that I proposed doesn't work. Did you try it?
