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+[[!meta copyright="Copyright © 2012 Free Software Foundation, Inc."]]
+
+[[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable
+id="license" text="Permission is granted to copy, distribute and/or modify this
+document under the terms of the GNU Free Documentation License, Version 1.2 or
+any later version published by the Free Software Foundation; with no Invariant
+Sections, no Front-Cover Texts, and no Back-Cover Texts.  A copy of the license
+is included in the section entitled [[GNU Free Documentation
+License|/fdl]]."]]"""]]
+
+[[!tag open_issue_documentation open_issue_gnumach]]
+
+
+# IRC, freenode, #hurd, 2012-02-01
+
+    <sekon> on Hurd what is the difference between kernel memory object and
+      pmap module ??
+    <sekon> pmap is heap/libraries table for each thread while kernel memory
+      object refers to arbitary blobs of data ??
+    <braunr> sekon: pmap is the low level memory mapping module
+    <braunr> i.e. it programs the mmu
+    <braunr> and these aren't hurd-specific, they are mach modules
+    <sekon> braunr: so kernel memonry objects consists of a bunch of pmaps ??
+    <braunr> sekon: memory objects can be various things, be specific please
+    <braunr> (they're certainly not a bunch of pmaps though, no)
+    <braunr> there is one pmap per vm_map, and there is one vm_map per task
+    <braunr> and there is no need for double question marks, is ther ??
+    <sekon> lol then is kernel memory object , please excuse the metaphor
+      something like a base class for pmap 
+    <braunr> i don't know what a "kernel memory object" is, be specific please,
+      again
+    <sekon> braunr:
+      http://courses.cs.vt.edu/~cs5204/fall05-gback/presentations/MachOS_Rajesh.ppt 
+    <sekon> goto page titled External Memory Management (EMM) on page 15 
+    <sekon> Kernel memory object shows up 
+    <braunr> you know there are other formats for this document
+    <sekon> nope .. i did not know that 
+    <sekon> in page 17 pmamp shows up 
+    <braunr> "the problems of external memory management" ?
+    <sekon> braunr: the paper i am also reading is called x15mach_thesis 
+    <braunr> ah, that's mine
+    * sekon bows 
+    <sekon> :) 
+    <braunr> ok i see page 17
+    <sekon> so please good sir explain the relationship between kernel memory
+      object and pmap 
+    <sekon> (if any) 
+    <sekon> braunr: there is no mention of kernel  memory object 
+    <braunr> again, i don't see any reference or definition of "kernel memory
+      object"
+    <sekon> but your paper says 
+    <sekon> that when page faults occur 
+    <sekon> the kernel contact the manager for a kernel reference object 
+    <sekon> *memory 
+    <braunr> where ?
+    <sekon> in section 2.1.3 (unless i read it wrong) 
+    <sekon> no just a sec 
+    <sekon> 2.1.5 
+    <braunr> i never used the expression "kernel memory object" there :p
+    <braunr> anyway, you're referring simple to memory objects as seen by
+      userspace pagers
+    <braunr> a memory object is a data container
+    <braunr> usually, it's a file
+    <braunr> but it can be anything
+    <braunr> the pager is the task that provides its content and implements the
+      object methods
+    <braunr> as for the relation between them and the pmap module, it's a
+      distant one
+    <braunr> i'll explain it with an example
+    <braunr> page fault -> request content of memory object at a given offset
+      with given length from pager -> ask pmap to establish the mapping in the
+      mmu
+    <sekon> braunr: thank you ver much 
+    <sekon> *very