IRC.

1 files changed, 22 insertions, 0 deletions

diff --git a/microkernel/mach/gnumach/memory_management.mdwn b/microkernel/mach/gnumach/memory_management.mdwn
index 43b99d83..ca2f42c4 100644
--- a/microkernel/mach/gnumach/memory_management.mdwn
+++ b/microkernel/mach/gnumach/memory_management.mdwn
@@ -80,3 +80,25 @@ IRC, freenode, #hurd, 2011-06-09
     <braunr> wow
     <braunr> i remember the linux support for 4G/4G split when there was enough
       RAM to fill the kernel space with struct page entries
+
+
+IRC, freenode, #hurd, 2011-11-12
+
+    <youpi> well, the Hurd doesn't "artificially" limits itself to 1.5GiB
+      memory
+    <youpi> i386 has only 4GiB addressing space
+    <youpi> we currently chose 2GiB for the kernel and 2GiB for the userspace
+    <youpi> since kernel needs some mappings, that leaves only 1.5GiB usable
+      physical memory
+    <sea4ever`> Hm? 2GiB for kernel, 2GiB for userspace, 500MiB are used for
+      what?
+    <youpi> for mappings
+    <youpi> such as device iomap
+    <youpi> contiguous buffer allocation
+    <youpi> and such things
+    <sea4ever`> Ah, ok. You map things in kernel space into user space then.
+    <youpi> linux does the same without the "bigmem" support
+    <youpi> no, just in kernel space
+    <youpi> kernel space is what determines how much physical memory you can
+      address
+    <youpi> unless using the linux-said-awful "bigmem" support