On Mon 12-07-21 09:41:26, David Hildenbrand wrote: > On 12.07.21 09:03, Michal Hocko wrote: > > [Cc linux-api] > > > > On Fri 09-07-21 10:50:48, Evan Green 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. > > > > Could you expand some more on why a strict exclusion is really > > necessary? I do understand that one might not want to have swap storage > > available all the time but considering that swapon is really a light > > operation so something like the following should be a reasonable > > workaround, no? > > swapon storage/file > > s2disk > > swapoff storage > > I'm certainly not a hibernation expert, but I'd guess this can also be > triggered by HW events, so from the kernel and not only from user space > where your workaround would apply. Is there anything preventing such a HW event doing the equivalent of the above? -- Michal Hocko SUSE Labs
