Illogical usage of swap

[Colin J. Raven]

On Mar 16 at 15:34, Giorgos Keramidas suggested:

>>>>>> Free memory (or the lack thereof) isn't the issue though.
>>>>>>
>>>>>> The issue is this:
>>>>>> Swap: 8192M Total, 116K Used, 8192M Free
>>>>>> and that's the piece of the puzzle that has us all utterly baffled.
>>>>>>
>>>>>> No way in creation this box should be swapping.
>>>>>
>>>>> Do you, by any chance, have vm.swap_idle_enabled set to 1?
>>>>
>>>> No, it isn't:
>>>> gonzo# sysctl -a |grep vm.swap_idle_enabled
>>>> vm.swap_idle_enabled: 0
>>>
>>> Strange.  AFAIK, processes are not swapped out to disk unless there is a
>>> severe memory shortage.  The usual case is to have them "paged" out,
>>> which is a bit different.
>>
>> That was my understanding also, and that's what's baffling us
>
> Unless, of course, there _was_ a short period of memory shortage, some
> processes were swapped out (a pair of idle getty instances, for example)
> and they were never swapped back in because they are still idle.
>
> You can probably track this down to the specific process or processes
> that have the PS_INMEM bit turned off in their proc->p_sflag.  But 116K
> seems too small to be a complete process.

This is going way above my head now, but great as a learning process 
anyway!

May I ask how we would go about tracking processes with the 
PS-INMEM bit turned off? That sounds as if - to me, still a journeyman 
on the road to knowledge - grepping multiple source trees might be 
necessary, which frankly is a daunting process (to say the very least). 
Is there one meta-search string that would show this? and if so, where 
should this search be applied?

Regards,
-Colin
--
Colin J. Raven
Wed Mar 16 14:43:00 CET 2005