3 files changed, 99 insertions, 3 deletions
diff --git a/microkernel/discussion.mdwn b/microkernel/discussion.mdwn
new file mode 100644
index 00000000..a5a73e18
--- /dev/null
+++ b/microkernel/discussion.mdwn
@@ -0,0 +1,24 @@
+[[!meta copyright="Copyright © 2011 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]]
+
+IRC, freenode, #hurd, 2011-07-26:
+
+    < antrik> Tekk_`: regarding microkernels: the basic idea, and really the
+      *only* fundamental difference, is that they isolate things in separate
+      address spaces. everything else goes back to this.
+    < antrik> benefits from the isolation generally fall into two groups: more
+      robustness (main focus of Minix3), and more flexibility (main focus of
+      Hurd)
+    < antrik> while it might also encourage some other good design choices,
+      these are secondary effects: such choices can also be implemented in a
+      monolithic architecture -- and not necessarily harder. just less obvious
+      in some cases...
diff --git a/microkernel/mach/gnumach/boot_trace.mdwn b/microkernel/mach/gnumach/boot_trace.mdwn
index d33ef25a..1badf712 100644
--- a/microkernel/mach/gnumach/boot_trace.mdwn
+++ b/microkernel/mach/gnumach/boot_trace.mdwn
@@ -1,12 +1,13 @@
-[[!meta copyright="Copyright © 2007, 2008 Free Software Foundation, Inc."]]
+[[!meta copyright="Copyright © 2007, 2008, 2011 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]]."]]"""]]
+is included in the section entitled [[GNU Free Documentation
+License|/fdl]]."]]"""]]
 
 `if NCPUS > 1` stuff is not being considered so far.
 
@@ -215,6 +216,12 @@ is included in the section entitled
 
 >> kern/bootstrap.c: bootstrap\_create
 
+>>> The [[grub/multiboot]] modules have been put somewhere into memory by
+>>> [[GRUB]].  The boot scripts are parsed.  The modules' ELF image's `PT_LOAD`
+>>> sections are \`\`read'' (that is, `vm_allocate` and `copyout`) and turned
+>>> into real [[task]]s.  The multiboot modules' memory regions can be
+>>> deallocated then.
+
 >> [...]
 
 >> vm\_pageout
diff --git a/microkernel/mach/memory_object/discussion.mdwn b/microkernel/mach/memory_object/discussion.mdwn
new file mode 100644
index 00000000..c874b255
--- /dev/null
+++ b/microkernel/mach/memory_object/discussion.mdwn
@@ -0,0 +1,65 @@
+[[!meta copyright="Copyright © 2011 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, 2011-08-05:
+
+    < neal> braunr: For instance, memory objects are great as they allow you to
+      specify the mapping policy in user space.
+    < neal> braunr: But, the policy for determining the eviction order is
+      realized by Mach
+    < neal> braunr: And user-space has no control
+    < braunr> are you referring to the page cache lru approximation and stuff
+      like resource containers ?
+    < neal> I'm not sure what you mean by page cache lru appoximateion
+    < braunr> the kernel eviction policy :)
+    < neal> that's an implementation detail
+
+IRC, freenode, #hurd, 2011-09-05:
+
+    <braunr> mach isn't a true modern microkernel, it handles a lot of
+      resources, such as high level virtual memory and cpu time
+    <braunr> for example, the page replacement mechanism can't be implemented
+      outside the kernel
+    <braunr> yet, it provides nothing to userspace server to easily allocate
+      resources on behalf of clients
+    <braunr> so, when a thread calls an RPC, the cpu time used to run that RPC
+      is accounted on the server task
+    <braunr> the hurd uses lots of external memory managers
+
+[[external_pager_mechanism]].
+
+    <braunr> but they can't decide how to interact with the page cache
+    <braunr> the kernel handles the page cache, and initiates the requests to
+      the pagers
+    <cjuner> braunr, why can't they decide that?
+    <braunr> because it's implemented in the kernel
+    <braunr> and there is nothing provided by mach to do that some other way
+    <slpz_> braunr: you probably already know this, but the problem with client
+      requests being accounted on behalf the server, is fixed in Mach with
+      Migrating Threads
+
+[[open_issues/mach_migrating_threads]].
+
+    <braunr> slpz_: migrating threads only fix the issue for the resources
+      managed by mach, not the external servers
+    <braunr> slpz_: but it's a (imo necessary) step to completely solve the
+      issue
+    <braunr> in addition to being a great feature for performance (lighter
+      context switchers, less state to track)
+    <braunr> it also helps priority inversion problems
+    <slpz_> braunr: I was referring just to cpu-time, but I agree with you an
+      interface change is needed for external pagers
+    <braunr> slpz_: servers in general, not necessarily pagers
+    <slpz_> as a way to mitigate the effect of Mach paging out to external
+      pagers, the folks at OSF implemented an "advisory pageout", so servers
+      are "warned" that they should start paging out, and can decide which
+      pages are going to be flushed by themselves