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+[[!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
+
+[[open_issues/resource_management_problems]].