465,7 → 465,25 |
levels can be left out, depending on the hardware hierachy or |
structure of software-only page tables. The genericity is achieved |
through a set of macros that define transitions from one level to |
another. Unused levels are optimised out by the compiler.</para> |
another. Unused levels are optimised out by the compiler. |
<figure float="1"> |
<mediaobject id="mm_pt"> |
<imageobject role="pdf"> |
<imagedata fileref="images/mm_pt.pdf" format="PDF" /> |
</imageobject> |
|
<imageobject role="html"> |
<imagedata fileref="images/mm_pt.png" format="PNG" /> |
</imageobject> |
|
<imageobject role="fop"> |
<imagedata fileref="images/mm_pt.svg" format="SVG" /> |
</imageobject> |
</mediaobject> |
|
<title>Hierarchical 4-level page tables.</title> |
</figure> |
</para> |
</section> |
|
<section> |
488,8 → 506,26 |
there is only a single global page hash table in the system while |
hierarchical page tables exist per address space. Thus, the global |
page hash table contains information about mappings of all address |
spaces in the system.</para> |
spaces in the system. |
<figure float="1"> |
<mediaobject id="mm_hash"> |
<imageobject role="pdf"> |
<imagedata fileref="images/mm_hash.pdf" format="PDF" /> |
</imageobject> |
|
<imageobject role="html"> |
<imagedata fileref="images/mm_hash.png" format="PNG" /> |
</imageobject> |
|
<imageobject role="fop"> |
<imagedata fileref="images/mm_hash.svg" format="SVG" /> |
</imageobject> |
</mediaobject> |
|
<title>Global page hash table.</title> |
</figure> |
</para> |
|
<para>The global page hash table mechanism uses the generic hash table |
type as described in the chapter dedicated to <link |
linkend="hashtables">data structures</link> earlier in this |