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Don't compare swap usage to Linux: it isn't known if this comparison is

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still true.

Expand a bit on what &os; might do with the extra memory.

Approved by:	bcr (mentor)
This commit is contained in:
Eitan Adler 2013-01-13 05:52:35 +00:00
parent 5c4e36738c
commit e8b50cb82d
Notes: svn2git 2020-12-08 03:00:23 +00:00 
svn path=/head/; revision=40595
1 changed files with 5 additions and 7 deletions
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12
en_US.ISO8859-1/books/faq/book.xml
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@ -7960,18 +7960,16 @@ hint.sio.7.irq="12"</programlisting>
<qandaset>
<qandaentry>
<question id="more-swap">
<para>&os; uses far more swap space than &linux;. Why?</para>
<para>&os; a lot of swap space even when the computer has
free memory left. Why?</para>
</question>
<answer>
<para>&os; only appears to use more swap than &linux;. In
actual fact, it does not. The main difference between &os;
and &linux; in this regard is that &os; will proactively
<para>&os; will proactively
move entirely idle, unused pages of main memory into swap in
order to make more main memory available for active use.
&linux; tends to only move pages to swap as a last resort.
The perceived heavier use of swap is balanced by the more
efficient use of main memory.</para>
This heavy use of swap is balanced by using the extra free
memory for cacheing.</para>
<para>Note that while &os; is proactive in this regard, it
does not arbitrarily decide to swap pages when the system is