Re: kern/54969 (Disk cache is no longer flushed on shutdown)

[Jason Thorpe <thorpej%me.com@localhost>]

> On Jul 31, 2020, at 12:38 PM, matthew green <mrg%eterna.com.au@localhost> wrote:
> 
> nice work.  i like how it's fairly simple.
> 
> you probably need to care about VMSWAP option.
> 
> i'd like to see some tests performed where a system is rebooted
> when it is full of ram and swap -- i fear that this will generate
> useless IO that may hang.  also, an option to skip it, maybe just
> use RB_NOSYNC?

I think there should be an option to swap_off() to just toss the data, rather than page it all back in.  That would solve the problem you're concerned about.

I was also thinking that disabling swap BEFORE unmounting all of the file systems would be a good idea, because there might be file-backed swap.

-- thorpej