Messages in this thread | | | Subject | Re: [PATCH v2] mm: Enable suspend-only swap spaces | From | David Hildenbrand <> | Date | Mon, 12 Jul 2021 09:41:26 +0200 |
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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.
-- Thanks,
David / dhildenb
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