On Sun, Jul 12, 2020 at 08:51:26PM -0700, Linus Torvalds wrote: > > > Maybe saying "doing the pmd copies for the initial stack isn't > > > important, so let's just note this as a special case and get rid of > > > the WARN_ON()" might be an alternative solution. > > > > Personally, I feel it is better to keep the warning just so in the future we > > can detect any bugs. > > I don't disagree, the warning didn't happen to find a bug now, but it > did fine a case we might be able to do better. > > So now that I feel we understand the issue, and it's not a horrible > problem, just a (very hard to trigger) warning, I don't think there's > any huge hurry. > > I think think I will - for now - change the WARN_ON() to > WARN_ON_ONCE() (so that it doesn't floow the logs if somebody triggers > this odd special case this malisiously), and add a note about how > this happens to the code for posterito. > > And if/when you figure out a better way to fix it, we can update the note. > > Ok? Yes, that sounds great to me. thanks, - Joel