Merge remote-tracking branch 'fp/master'

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diff --git a/microkernel/mach/gnumach/memory_management.mdwn b/microkernel/mach/gnumach/memory_management.mdwn
index 3e158b7c..a1d9a99d 100644
--- a/microkernel/mach/gnumach/memory_management.mdwn
+++ b/microkernel/mach/gnumach/memory_management.mdwn
@@ -133,3 +133,47 @@ License|/fdl]]."]]"""]]
     <braunr> using sysenter/sysexit makes it even faster
 
 [[open_issues/system_call_mechanism]].
+
+
+# IRC, freenode, #hurd, 2012-12-12
+
+    <braunr> youpi: is the 2g split patch really needed ?
+    <braunr> or rather, is it really a good thing for most people ?
+    <braunr> instead of the common 3g/1g
+    <braunr> it reduces tasks' address space but allows the kernel to reference
+      more physical memory
+    <braunr> the thing is, because of the current page cache implementation,
+      most of the time, this physical memory remains unused, or very rarely
+    <youpi> ?
+    <braunr> on the other hand, a larger address space for tasks allows running
+      more threads (more space for tasks) and not failing while linking webkit
+      .. :)
+    <youpi> it's needed for quite a few compilations, yes
+    <braunr> if you refer to the link stage, with a decent amount of swap, it
+      goes without trouble
+    <youpi> well, if your kernel doesn't have 2GiB physical addressing
+      capacity, userspace won't have >2GiB memory capacity either
+    <youpi> does it now?
+    <youpi> it didn't use to
+    <youpi> and it was crawling like hell for some builds
+    <youpi> (until simply hanging)
+    <braunr> i never have a problem e.g. runing the big malloc glibc test
+    <braunr> (bug22 or something like that)
+    <youpi> that doesn't involve objects from the fs, does it?
+    <braunr> no
+    <braunr> as long as it's anonymous memory, it's ok
+    <braunr> the default pager looks safe, i'm pretty sure our lockups are
+      because of something in ext2fs
+    <youpi> braunr: well, an alternative would be to build two kernels, one 2/2
+      and one 3/1
+    <braunr> not really worth it
+    <braunr> i was just wondering
+    <braunr> i usually prefer a 3/1 on darnassus, but i don't build as often as
+      a buildd :x
+    <youpi> or we can go with 2.5/1.5
+    <youpi> I can do that on bach & mozart for instance
+    <youpi> (they have their own kernel anyway)
+    <braunr> youpi: if you think it's worth the effort
+    <braunr> again, i was just wondering out loud
+    <youpi> braunr: well, bach & mozart don't have > 1.2GiB mem anyway
+    <youpi> so it doesn't pose problem