1 files changed, 49 insertions, 0 deletions
diff --git a/open_issues/resource_management_problems/io_accounting.mdwn b/open_issues/resource_management_problems/io_accounting.mdwn
new file mode 100644
index 00000000..113b965a
--- /dev/null
+++ b/open_issues/resource_management_problems/io_accounting.mdwn
@@ -0,0 +1,49 @@
+[[!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]]."]]"""]]
+
+IRC, freenode, #hurd, 2011-07-22
+
+    <braunr> an interesting question i've had in mind for a few weeks now is
+      I/O accounting
+    <braunr> what *is* I/O on a microkernel based system ?
+    <braunr> can any cross address space transfer be classified as I/O ?
+
+IRC, freenode, #hurd, 2011-07-29
+
+    < braunr> how does the hurd account I/O ?
+    < youpi> I don't think it does
+    < youpi> not an easy task, actually
+    < youpi> since gnumach has no idea about it
+    < braunr> yes
+    < braunr> another centralization issue
+    < braunr> does network access count as I/O on linux ?
+    < youpi> no
+    < braunr> not even nfs ?
+    < youpi> else you'd get 100% for servers :)
+    < braunr> right
+    < youpi> nfs goes through vfs first
+    < braunr> i'll rephrase my question
+    < youpi> I'd need to check but I believe it can check nfs
+    < braunr> does I/O accounting occur at the vfs level or block layer ?
+    < youpi> I don't know, but I beleive vfs
+    < youpi> (at least that's how I'd do it)
+    < braunr> i don't have any more nfs box to test that :/
+    < braunr> personally i'd do it at the block layer :)
+    < youpi> well, both
+    < youpi> so e2fsck can show up too
+    < braunr> yes
+    < youpi> it's just a matter of ref counting
+    < youpi> apparently nfs doesn't account
+    < youpi> find . -printf "" doesn't show up in waitio
+    < braunr> good
+    < youpi> well, depends on the point of view
+    < youpi> as a user, you'd like to know whether your processes are stuck on
+      i/o (be it disk or net)
+    < braunr> this implies clearly defining what io is