On Feb 8, 2017 10:19 AM, "Julie Marchant" onpon4@riseup.net wrote:
Besides, swap isn't a solution to low RAM, it's a failsafe. Some people might find the cost of degrading a microSD card to be worth that failsafe, as opposed to just letting some programs crash, but I think most people would prefer the latter option for the most part.
But if you really use it as a failsafe (that is, very rarely, and only long enough to notice the slowdown and close some programs), it doesn't degrade the flash much at all. It's only, IMO, a big deal when you're trying to pretend your system has more RAM than it does, and thus using swap regularly.
As you say, different people will make different choices, but for me swap-on-SD is clearly worth it, so if/when an out-of-memory condition _does_ occur, I get a chance to choose which processes live and die, and to make sure any important work is saved properly. I don't wholly distrust the kernel OOM killer's heuristics, but heuristics are never perfect, and the cost in flash usage seems very reasonable to me.
However, since the default needs to be one or the other, and we can't even know that users will _have_ a microSD card in it, I'd agree that the factory image should have swap disabled. But I'd say it should have documentation or scripts to make it easy for end users to enable swap on removable (thus replaceable) storage if they want to. And it _definitely_ shouldn't ship with a kernel or userland incapable of swapping, like some Android devices I've used; but I expect we all agree on that.
Benson Mitchell