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

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

The following reply was made to PR kern/54969; it has been noted by GNATS.

From: Jason Thorpe <thorpej%me.com@localhost>
To: matthew green <mrg%eterna.com.au@localhost>
Cc: gnats-bugs%netbsd.org@localhost,
 "J. Hannken-Illjes" <hannken%eis.cs.tu-bs.de@localhost>,
 kern-bug-people%netbsd.org@localhost,
 gnats-admin%netbsd.org@localhost,
 netbsd-bugs%netbsd.org@localhost,
 Andreas Gustafsson <gson%gson.org@localhost>
Subject: Re: kern/54969 (Disk cache is no longer flushed on shutdown)
Date: Fri, 31 Jul 2020 15:35:00 -0700

 > On Jul 31, 2020, at 12:38 PM, matthew green <mrg%eterna.com.au@localhost> wrote:
 >=20
 > nice work.  i like how it's fairly simple.
 >=20
 > you probably need to care about VMSWAP option.
 >=20
 > 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