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From: Sam Lawrance <boris@brooknet.com.au>
To: David Xu <davidxu@freebsd.org>
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Date: Sun, 06 Mar 2005 13:49:29 +1100
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cc: current@freebsd.org
Subject: Re: Swapped out procs not brought in immediately after child exits
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On Sun, 2005-03-06 at 09:43 +0800, David Xu wrote:
> Sam Lawrance wrote:
> 
> >>How-To-Repeat:
> >>    
> >>
> >
> >Run a shell somewhere (first). Su or run another shell or similar (second).
> >Wait until the first shell has swapped out (might require running some other
> >memory hogs). Exit the second shell. Notice that the second shell takes a
> >long time to exit.
> >
> >  
> >
> This reminds me that it is another swappable kernel stack problem, if we 
> don't have
> it, we even needn't TDP_WAKEPROC0  hack, interesting. :)

Do I understand this correctly: When a process is swapped back in, the
kernel stack is faulted in immediately and user space is faulted in as
needed?

And without swappable kernel stack, no extra action is required because
the kernel stack is already in, and user space will be faulted in as
usual?