Date: Tue, 28 Jan 2014 11:42:10 -0500 From: John Baldwin <jhb@freebsd.org> To: freebsd-stable@freebsd.org Cc: Ronald Klop <ronald-lists@klop.ws> Subject: Re: Processes are incorrectly marked as swapped out Message-ID: <201401281142.10317.jhb@freebsd.org> In-Reply-To: <op.w9446fkykndu52@ronaldradial.radialsg.local> References: <2D47B79E-C171-4B91-B0AB-4DD2212770C6@gmail.com> <op.w9446fkykndu52@ronaldradial.radialsg.local>
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On Thursday, January 23, 2014 8:02:29 am Ronald Klop wrote: > On Thu, 23 Jan 2014 13:19:36 +0100, Dmitry Sivachenko > <trtrmitya@gmail.com> wrote: > > > Hello! > > > > After upgrade from stable/9 to stable/10 I see the following regression. > > Some processes are marked as swapped out in top(1) output: > > > > 1436 root 1 43 0 16524K 0K nanslp 14 1:14 0.00% > > <cron> > > 1381 smmsp 1 20 0 23988K 0K pause 18 0:04 0.00% > > <sendma > > 99348 mitya 1 21 0 23492K 0K pause 16 0:00 0.00% > > <csh> > > > > ps(1) also shows them as swapped out (W as second character in state > > field): > > 1381 - IWs 0:00.00 sendmail: Queue runner at 00:30:00 for > > /var/spool/clie > > 1436 - IWs 0:00.00 /usr/sbin/cron -s > > 80231 - IWs 0:00.00 /usr/local/sbin/collectdmon -c > > /usr/local/sbin/coll > > 99348 1 IWs 0:00.00 -csh (csh) > > > > Though swapinfo reports that zero swap is used and even if I turn swap > > completely off (swapoff -a) > > the output of both top(1) and ps(1) does not change: these processes are > > still marked as swapped out. > > The code of an application can get removed from memory, because there > still is an image of it in the executable on disk. It can be 'swapped' in > by reading the executable again. The program is memory mapped (mmap). > See VN PAGER vs SWAP PAGER in 'systat -vm'. However, a swapped out process always uses swap (for kernel stacks), so this seems like a real bug. -- John Baldwin
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