[o11c]

An ivory tower answer.

All those arguments would be useful if we somehow could avoid the fact that the system will use it as "emergency memory" and become unresponsive. The kernel's OOM killer is broken for this, and userland OOM daemons are unreliable. `vm.swappiness` is completely useless in the worst case, which is the only case that matters.

With swap off, all the kernel needs to do is reserve a certain threshold for disk cache to avoid the thrashing problem. I don't know what the kernel actually does here (or what its tunables are), because systems with swap off have never caused problems for me the way systems with swap on inevitably do. The OOM killer works fine with swap off, because a system must always be resilient to unexpected process failure.

And worst of all - the kernel requires swap (and its bugs) to be enabled for hibernation to work.

It really wouldn't be hard to design a working swap system (just calculate how much to keep of different purposes of swap, and launch the OOM killer earlier), but apparently nobody in kernel-land understands the real-world problems enough to bother.

[em-bee]

the kernel requires swap (and its bugs) to be enabled for hibernation to work

this one gets me irritated every time i think about it. i don't want to use swap, but i do want hibernation. why is there no way to disable swap without that?

hmm, i suppose one could write a script that enables an inactive swap partition just before shutdown, and disables it again after boot.

[sigio]

I never want to use hibernation, since then I have to re-enter my disk encryption passphrase at resume time, have to wait longer for both suspend and resume because it needs to sync upto 48GB to/from disk (and I don't want to waste 48GB of diskspace for swapspace/hibernation). Suspend to ram is fine, I can keep the system suspended for a couple of days without issues, but it only needs to survive a long weekend at most. Resume from RAM is about instant, and then just needs a screensaver unlock to get back to work.

[chronid]

And i want to use hibernation, as I don't mind putting my disk encryption passphrase once a day as the price of not risking having my laptop with a completely drained battery on Monday morning due to 1% battery drain/h of s2idle in my 64GB RAM configuration.

You can use suspend+hibernate to accomplish that and it works well. Unless the gods of kernel lockdown decide you cannot for your own good (and it doesn't matter if your disk is fully encrypted, you're not worthy anyway) of course. It's their kernel running on your laptop after all.