freebsd stable - Feb 2016 - intr using Swap

On 2016-02-17 11:36 am, Efra?n D?ctor wrote:
> Hello.
> 
> This past few days, on a dedicated server I'm seeing that swap space
> is being used while there are plenty of RAM to be used:
> 
> Mem: 14G Active, 39G Inact, 7723M Wired, 504M Cache, 1864M Buf, 593M 
> Free
> Swap: 8192M Total, 1567M Used, 6625M Free, 19% Inuse, 108K In
> 
> After investigating, I swa that the process using swap is intr:
> 
> Result of ps ax | grep W:
> 12  -  WL       937:48.07 [intr]
> 
> uname -a:
> FreeBSD edh.hyrule.mx 10.1-RELEASE-p24 FreeBSD 10.1-RELEASE-p24 #0:
> Mon Nov  2 12:17:28 UTC 2015
> root at amd64-builder.daemonology.net:/usr/obj/usr/src/sys/GENERIC amd64
> 
> Is there any reason for intr to be using swap space? Is this normal?
I believe you are incorrectly reading it, the first character of the 
state line being a W Marks an idle interrupt thread, W only means 
swapped out if its an additional character in the section.

man ps
  [...snip...]
  state     The state is given by a sequence of characters, for example,
                ``RWNA''.  The first character indicates the run state
of
the
                process:
  [...snip...]
                W       Marks an idle interrupt thread.
  [...snip...]
                Additional characters after these, if any, indicate 
additional
                state information:
  [...snip...]
                W       The process is swapped out.
  [...snip...]

Even when there is available memory if an item has already been swapped 
it wont return to physical memory until the process needs access that 
memory. Its not uncommon to see systems that had a brief memory 
constraint leave some swap long after the memory has been cleared up.

-- 
Thanks,
    Dean E. Weimer
    http://www.dweimer.net/

El 17/02/2016 a las 12:34 p. m., dweimer escribi?:
> I believe you are incorrectly reading it, the first character of the 
> state line being a W Marks an idle interrupt thread, W only means 
> swapped out if its an additional character in the section.
>
> man ps
>  [...snip...]
>  state     The state is given by a sequence of characters, for example,
>                ``RWNA''.  The first character indicates the run
state
> of the
>                process:
>  [...snip...]
>                W       Marks an idle interrupt thread.
>  [...snip...]
>                Additional characters after these, if any, indicate 
> additional
>                state information:
>  [...snip...]
>                W       The process is swapped out.
>  [...snip...]
>
> Even when there is available memory if an item has already been 
> swapped it wont return to physical memory until the process needs 
> access that memory. Its not uncommon to see systems that had a brief 
> memory constraint leave some swap long after the memory has been 
> cleared up.
>
Hello.

Thank you for your response.

Using only /ps ax/ doesn't show any process being in swap. How can I 
determine what processes are being swapped out?