On Thu, Aug 12, 2021 at 12:57:41PM +0100, David Howells wrote: > > Hi Willy, Trond, > > Here's a change to make reads from the swapfile use async DIO rather than > readpage(), as requested by Willy. > > Whilst trying to make this work, I found that NFS's support for swapfiles > seems to have been non-functional since Aug 2019 (I think), so the first > patch fixes that. Question is: do we actually *want* to keep this > functionality, given that it seems that no one's tested it with an upstream > kernel in the last couple of years? Independ of the NFS use using the direct I/O code for swap seems like the right thing to do in generlal. e.g. for XFS a lookup in the extent btree will be more efficient than the weird swap extent map.