On Fri, 9 Jul 2021 10:50:48 -0700 Evan Green <evgreen@xxxxxxxxxxxx> wrote: > Currently it's not possible to enable hibernation without also enabling > generic swap for a given swap area. These two use cases are not the > same. For example there may be users who want to enable hibernation, > but whose drives don't have the write endurance for generic swap > activities. > > Add a new SWAP_FLAG_NOSWAP that adds a swap region but refuses to allow > generic swapping to it. This region can still be wired up for use in > suspend-to-disk activities, but will never have regular pages swapped to > it. > > Swap regions with SWAP_FLAG_NOSWAP set will not appear in /proc/meminfo > under SwapTotal and SwapFree, since they are not usable as general swap. > This patch doesn't appear to set SWAP_FLAG_NOSWAP anywhere. Perhaps there's another patch somewhere which changes the hibernation code? If so, can we please have both patches in a series? Once we have a description of how this thing gets set, please let's discuss what happens if someone tries to enable generic swap onto that device after hibernation has set SWAP_FLAG_NOSWAP (I'm basically guessing now). Will it work? Is there a backward-compatibility issue here?
