On Thu, Jun 06, 2019 at 10:11:58AM -0700, Ira Weiny wrote: > 2) This is a bit more subtle and something I almost delayed sending these out > for. Currently the implementation of a lease break actually removes the > lease from the file. I did not want this to happen and I was thinking of > delaying this patch set to implement something which keeps the lease around > but I figured I should get something out for comments. Jan has proposed > something along these lines and I agree with him so I'm going to ask you to > read my response to him about the details. > > > Anyway so the key here is that currently an app needs the SIGIO to retake > the lease if they want to map the file again or in parts based on usage. > For example, they may only want to map some of the file for when they are > using it and then map another part later. Without the SIGIO they would lose > their lease or would have to just take the lease for each GUP pin (which > adds overhead). Like I said I did not like this but I left it to get > something which works out. So to be clear.. Even though the lease is broken the GUP remains, the pages remain pined, and truncate/etc continues to fail? I like Jan's take on this actually.. see other email. Jason
