IRC.

1 files changed, 35 insertions, 0 deletions

diff --git a/open_issues/gnumach_tick.mdwn b/open_issues/gnumach_tick.mdwn
new file mode 100644
index 00000000..eed447f6
--- /dev/null
+++ b/open_issues/gnumach_tick.mdwn
@@ -0,0 +1,35 @@
+[[!meta copyright="Copyright © 2012 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_gnumach]]
+
+
+# IRC, freenode, #hurd, 2012-07-05
+
+    <pinotree> braunr: wrt to mach: it seems to me it ticks every 10ms or so,
+      it is true?
+    <braunr> yes
+    <braunr> and it's not preemptible
+    <pinotree> braunr: that means a gnumach kernel currently has a maximum
+      uptime of almost 500 days
+    <braunr> pinotree: what do you mean ?
+    <pinotree> there's an int (or uint, i don't remember) variable that keeps
+      the tick count
+    <braunr> yes the tick variable should probably be a 64-bits type
+    <braunr> or a struct
+    <braunr> but the tick count should only be used for computation on "short"
+      delays
+    <braunr> and it should be safe to use it even when it overflows
+    <braunr> it's not the wall clock
+    <pinotree> i found that when investigating why the maximum timeout for a
+      mach_msg is like INT_MAX >> 2 (or 4) or something like that, also due to
+      the tick count
+    <braunr> iirc, in linux, they mostly use the lower 32-bits on 32-bits
+      architecture, updating the 32 upper only when necessary