On Thu, Aug 15, 2024 at 11:41:23PM +0200, David Hildenbrand wrote: > On 14.08.24 19:36, Matthew Wilcox wrote: > > I believe these two flags have entirely disjoint uses and there will > > be no confusion in amalgamating them. > > > > Anonymous memory (re)uses mappedtodisk for anon_exclusive. > > Anonymous memory does not use PG_private_2. > > Also not when they are in the swapcache, right? Correct, swapcache has no use of PG_private_2. > > The one thing that's going to stand in the way of this is that various > > parts of the VFS treat private_2 as a "wait for this bit to be clear", > > due to its use in fscache (which is going away). > > > > So my approach here is going to be: > > > > - Rename mappedtodisk to be PG_owner_priv_2 (add appropriate aliases) > > - Switch btrfs to use owner_priv_2 instead of private_2 > > - Wait for the fscache use of private2 to finish its deprecation cycle > > - Remove private_2 entirely > > > > Sound good? > > Yes, one step into the right direction. Cool, thanks.
