vm_swapout: Restore handling of RLIMIT_RSS

In commit 13a1129d700c, I removed the mechanism by which the pagedaemon
signals the swapout thread when page reclamation is unable to keep up
with demand.  This is because the swapout thread's main action in this
case is to swap out sleeping processes, but we removed this support.

However, it had the secondary effect of causing the swapout thread to
enforce RLIMIT_RSS when racct is not enabled.  Without it, if
racct_enabled is false, nothing ever kicks the swapout thread.

Restore the old behaviour of trying to enforce RLIMIT_RSS when the page
daemon is unable to keep up with demand.  I'm not at all convinced this
is a good way to implement the limit, but the change wasn't intentional,
so let's restore it for now.

Fixes:		13a1129d700c ("vm: Remove kernel stack swapping support, part 1")
Reviewed by:	olce, kib
MFC after:	2 weeks
Differential Revision:	https://reviews.freebsd.org/D56142

0 files changed, 0 insertions, 0 deletions