why the swapping



"Tim" == Tim Middleton <x@xxxxxxx> writes:

Tim> Running 6.0-release, with 2 gig ram. Typical memory stats like
Tim> this (from top):

Tim> 626M Active, 1045M Inact, 204M Wired, 75M Cache, 112M Buf, 22M
Tim> Free

Tim> Under moderately high load i'm seeing a lot of swapping
Tim> periodically through the day (and then load avg going way, way
Tim> up, of course). I'm wondering why is there, with so much inactive
Tim> memory, so much disk swapping?

Tim> The machine runs some fairly intense stuff, such as squid,
Tim> postgresql, and zope; but it seems to me there should be enough
Tim> RAM to cover all of this without swapping. What am I missing? Am
Tim> i misinterpretting the stats, and just not understanding how the
Tim> vm works?

Swapping in or out? Sswapping out is normal behaviour --- a
background kernel thread sweeps memory to move it from active to
inactive and inactive dirty pages are occaisionally sent to swap (or
the file that's backing them).

Swapping in is also normal when processes are launched. Remember that
*BSD's "swap in" processes.

I believe that mmap() calls also show up in the swap stats ...

Swapping doesn't mean what it used to. What should worry you is a
process that is blocked to a large degree on paging --- but that's not
likely happening.

Dave.

--
============================================================================
|David Gilbert, Independent Contractor. | Two things can be |
|Mail: dave@xxxxxxxx | equal if and only if they |
|http://daveg.ca | are precisely opposite. |
=========================================================GLO================
_______________________________________________
freebsd-stable@xxxxxxxxxxx mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-stable
To unsubscribe, send any mail to "freebsd-stable-unsubscribe@xxxxxxxxxxx"



Relevant Pages

  • Re: Closing ceremony
    ... I gave it three lots of 5 minutes (in between swapping recordings). ... I didn't see anything each time that made me want to continue watching. ...
    (uk.media.tv.misc)
  • Re: Gigabyte 8KNXP, Silicon Image 3112 Sata
    ... Thanks Tim for your input and your hints. ... > I would post this as a bug with VMWare - make sure you include your hardware ... > If you have a complex h/w config then consider simplifying it. ... > kick in above a certain memory spec level? ...
    (microsoft.public.windowsxp.general)
  • Re: Smartphone
    ... I'd like a capable phone, not top of the line, with a newer ... Go for lots and lots of system memory. ... card but you are stuck with the other. ... Tim Hill of timil.com. ...
    (comp.sys.acorn.misc)
  • RE: Driver Stop Error on OS Re-Install
    ... >>is a single processor board. ... >>Tim P. ... time before with different memory addresses. ...
    (microsoft.public.win2000.general)
  • RE: Driver Stop Error on OS Re-Install
    ... >is a single processor board. ... >Tim P. ... Hmmm ... do the same memory addresses show ...
    (microsoft.public.win2000.general)