Subject: Re: swapctl -a doesn't do load-balancing; whyzzat?
To: matthew green <>
From: Chuck Silvers <>
List: tech-kern
Date: 09/05/2000 21:02:36
On Wed, Sep 06, 2000 at 10:31:22AM +1100, matthew green wrote:
>    the other way that the swapslot for a page can change is if the page is
>    modified.  if the page is paged out again, the swapslot is reassigned.
> hmmm... isn't the code (uvm_pdaemon.c:uvmpd_scan_inactive()) saying that the
> swap page is reallocated every time the page is swapped out, whether it was
> modified or not?  ISTR the reason i did this is so we can do clustered swap
> writes, rather than only being able to write NBPG bytes at a time.  but it
> was far too long ago to recall precisely :-)

well yea, but a page is only written out again at all if it's been modified.
if it's unchanged since the last time we wrote it, we just free the copy
in memory.  I guess it *has* been a while for you..  :-)