mm: frontswap: lazy initialization to allow tmem backends to build/run as modules

With the goal of allowing tmem backends (zcache, ramster, Xen tmem) to
be built/loaded as modules rather than built-in and enabled by a boot
parameter, this patch provides "lazy initialization", allowing backends
to register to frontswap even after swapon was run.  Before a backend
registers all calls to init are recorded and the creation of tmem_pools
delayed until a backend registers or until a frontswap store is
attempted.

Signed-off-by: Stefan Hengelein <[email protected]>
Signed-off-by: Florian Schmaus <[email protected]>
Signed-off-by: Andor Daam <[email protected]>
Signed-off-by: Dan Magenheimer <[email protected]>
[v1: Fixes per Seth Jennings suggestions]
[v2: Removed FRONTSWAP_HAS_.. ]
[v3: Fix up per Bob Liu <[email protected]> recommendations]
[v4: Fix up per Andrew's comments]
Signed-off-by: Konrad Rzeszutek Wilk <[email protected]>
Signed-off-by: Bob Liu <[email protected]>
Cc: Wanpeng Li <[email protected]>
Cc: Dan Magenheimer <[email protected]>
Cc: Minchan Kim <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions