On 12/5/19 6:48 PM, John M. Harris Jr wrote:
c. Resource requirements are excessive, there's no dynamic allocation
so to be safe you need to allocate a minimum of 1x RAM for a swap
partition used for a hibernation image. As a consequence, there's now
an excessive amount of relatively slow swap which can result in swap
thrashing and the effective loss of the system. See "Better
interactivity in low-memory situations "
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What are you talking about? You should have at least 1x RAM for swap whether 
you use hibernation or not. If you're having issues, you can adjust the 
swappiness as needed. There is no "effective loss of the system" involved.

Many systems have 8, 16 or even 32GB of RAM now. Mine has 16GB, and and I regularly run out of memory because some Chrome tab is open to a website that keeps reloading ads and leaking memory, sometimes consuming gigabytes per tab.

The disk speed being in the double digit MB/s, swapping multiple GB takes minutes. During this time, the system is unresponsive, unfortunately---the mouse is frozen, alt-tab does not switch between apps, etc. Sometimes I can flip to a text console and kill chrome, but most of the time the only remedy is to wait it out or force reboot. I am not sure if the freezing is mostly kernel's fault or the display subsystem's fault.

For that reason, I don't believe that the old advice of swap = 2*RAMĀ  is relevant today. Even 1*RAM is of questionable utility---the main reason for 1*RAM guideline is the ability to hibernate to swap, in my opinion. Instead, I'd say that with the RAM prices being what they are, everyone should try to buy as much RAM as appropriate for their regular use.