On Wed, Feb 22, 2023 at 06:44:12PM -0800, Luis Chamberlain wrote: > In doing experimentations with shmem having the option to avoid swap > becomes a useful mechanism. One of the *raves* about brd over shmem is > you can avoid swap, but that's not really a good reason to use brd if > we can instead use shmem. Using brd has its own good reasons to exist, > but just because "tmpfs" doesn't let you do that is not a great reason > to avoid it if we can easily add support for it. > > I don't add support for reconfiguring incompatible options, but if > we really wanted to we can add support for that. > > To avoid swap we use mapping_set_unevictable() upon inode creation, > and put a WARN_ON_ONCE() stop-gap on writepages() for reclaim. > > Signed-off-by: Luis Chamberlain <mcgrof@xxxxxxxxxx> > --- We would have use-cases for this in systemd. We currently use ramfs for systemd's credential logic since ramfs is unswappable. It'd be very neat if we could use tmpfs instead, Acked-by: Christian Brauner <brauner@xxxxxxxxxx>
