[RFC] [PATCH] VM & VFS changes

[Andre Guibert de Bruet]

On Wed, 1 Jun 2005, Alexander Leidinger wrote:

> Poul-Henning Kamp <phk at phk.freebsd.dk> wrote:
>
>> Maybe the simplest solution is also the best:  keep track of the
>> dependencies and do the cleanup leaf->root on the resulting tree.
>
> How many userland processes have to be running and consuming memory which
> isn't available as physical RAM at this point in the shutdown sequence?
>
> Wouldn't a loop like the following be enough?
> while swap
>     umount unbusy-FS
>     swap-off swap
>
> This assumes that swap-off doesn't turns off the swap if it isn't able to put
> everything back into other swap or physical RAM areas.

I would think that one would want to disable swapping before the unmount 
of filesystems for the very fact you could have vnode-backed swapspace in 
use. Once the system is swapless at this point in shutdown, there should 
no longer be any active vnodes on mounted filesystems (From my testing, 
the only exception at this point in time is devfs. I am working on another 
patch to address this).

Andy

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