Date: Wed, 10 Dec 2003 19:08:57 -0700 From: <soralx@cydem.org> To: freebsd-hackers@freebsd.org Subject: Re: adding more ram Message-ID: <200312101849.34457.soralx@cydem.org> In-Reply-To: <2946E9F05C8DD511A7DC0002A5608CE401143D3F@gbchm201.exgb01.exch.eds.com> References: <2946E9F05C8DD511A7DC0002A5608CE401143D3F@gbchm201.exgb01.exch.eds.com>
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> The same was true for 10.20 and 11 Versions of HPUX - I believe there once
> was I very long going debate when the "new" FreeBSD vm was made on the
> issue. The fundamental question at the time was what to do when you run out
> of swap/vm space. The 1-1 backing of swap space was seen as a way to avoid
> that you have resort to kill random processes in order to free up space and
> the tradition with the 2-1 swap ratio used to have "a performance reason"
> in the initial Unix Swap and paging implementations. I can't seem to recall
> the actual reason
While we're at this topic, can somebody plz briefly explain how does swap
performance depend on swap size? From `man 7 tuning` (May 25, 2001):
The kernel's VM paging algorithms
are tuned to perform best when there is at least 2x swap versus main mem-
ory. Configuring too little swap can lead to inefficiencies in the VM
page scanning code as well as create issues later on if you add more mem-
ory to your machine.
Is this still true? For -CURRENT also?
10.12.2003; 18:42:17
[SorAlx] http://cydem.org.ua/
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