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 "
>
https://gcc01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fpagure....
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*RAM 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.