From owner-freebsd-hackers  Sat Jul 13  0:27:44 2002
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Date: Sat, 13 Jul 2002 00:27:41 -0700 (PDT)
From: Matthew Dillon <dillon@apollo.backplane.com>
Message-Id: <200207130727.g6D7Rft3076942@apollo.backplane.com>
To: David Schultz <dschultz@uclink.Berkeley.EDU>
Cc: Sean Kelly <smkelly@zombie.org>, hackers@FreeBSD.ORG
Subject: Re: swapoff?
References: <20020713040247.GA82181@edgemaster.zombie.org> <20020713052337.GA662@HAL9000.wox.org> <20020713053236.GA884@HAL9000.wox.org> <200207130652.g6D6qI93076722@apollo.backplane.com> <20020713071911.GA1558@HAL9000.wox.org>
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:Can't you have a race condition here where you decide that you
:have enough space, and by the time you've deallocated half of the
:swapfile that's no longer the case?  It seems like the correct
:thing to do in that case is abort the system call (which could be
:painful).  Perhaps the best thing to do in this case is wait for
:vm_pageout_scan to kill a few pigs.

    I wouldn't worry about it.  Nobody turns off swap on a running system
    at a whim.  It just needs to prevent stupid mistakes like trying to
    remove a swap device without having adequate memory + other swap to
    take care of the data.

					-Matt
					Matthew Dillon 
					<dillon@backplane.com>

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