I'm running a 700Mhz K7 with 256M of RAM as my workstation. I have
two fast SCSI drives with a Gig of swap between them. The system
shouldn't normally be a bottleneck as a workstation.
I find, however, that there seem to be some bad worst-case senerios
popping up rather often.
Netscape is a good (common) example, but other memory stresses will
show if the system is busy, too.
What I'm talking about is a situation where some portion of the
application will be swapped out and then when the application becomes
active again, the swap will grind heavily reading and writing for
10-20 seconds (pushing 5M/s out and 5M/s in).
Now the application in question (Netscape) usually runs around 50 to
75 megs, so that swapping activity is effectively swapping an amount
of memory equavalent to the whole application out and then in again.
My fear that this is a worst case scenario comes from this fact: that
some other part of the application now-just-recently-active-again is
being swapped out to bring in a part that was already swapped out.
Now, you could argue that this case is hard to avoid, but I find this
happening during periods of constant browsing ... such that only a
small amount of the application could have been out.
I'm positive that its not a case of the working set being larger than
physical memory; it's one of choice of page to swap.
Has anyone done any thinking about this behaviour? It occurs with
varying degree to many applications.
|David Gilbert, Velocet Communications. | Two things can only be |
|Mail: [EMAIL PROTECTED] | equal if and only if they |
|http://www.velocet.net/~dgilbert | are precisely opposite. |
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