IRC.

1 files changed, 37 insertions, 3 deletions

diff --git a/open_issues/performance/io_system/clustered_page_faults.mdwn b/open_issues/performance/io_system/clustered_page_faults.mdwn
index 37433e06..9e20f8e1 100644
--- a/open_issues/performance/io_system/clustered_page_faults.mdwn
+++ b/open_issues/performance/io_system/clustered_page_faults.mdwn
@@ -12,7 +12,10 @@ License|/fdl]]."]]"""]]
 
 [[community/gsoc/project_ideas/disk_io_performance]].
 
-IRC, freenode, #hurd, 2011-02-16
+[[!toc]]
+
+
+# IRC, freenode, #hurd, 2011-02-16
 
     <braunr> exceptfor the kernel, everything in an address space is
       represented with a VM object
@@ -88,9 +91,8 @@ IRC, freenode, #hurd, 2011-02-16
     <braunr> recommend*
     <etenil> ok
 
----
 
-IRC, freenode, #hurd, 2011-02-16
+# IRC, freenode, #hurd, 2011-02-16
 
     <antrik> etenil: OSF Mach does have clustered paging BTW; so that's one
       place to start looking...
@@ -103,3 +105,35 @@ IRC, freenode, #hurd, 2011-02-16
       can serve as a starting point
 
 <http://lists.gnu.org/archive/html/bug-hurd/2010-06/msg00023.html>
+
+
+# IRC, freenode, #hurd, 2011-07-22
+
+    <braunr> but concerning clustered pagins/outs, i'm not sure it's a mach
+      interface limitation
+    <braunr> the external memory pager interface does allow multiple pages to
+      be transfered
+    <braunr> isn't it an internal Mach VM problem ?
+    <braunr> isn't it simply the page fault handler ?
+    <antrik> braunr: are you sure? I was under the impression that changing the
+      pager interface was among the requirements...
+    <antrik> hm... I wonder whether for pageins, it could actually be handled
+      in the pages instead of Mach... though this wouldn't work for pageouts,
+      so probably not very helpful
+    <antrik> err... in the pagers
+    <braunr> antrik: i'm almost sure
+    <braunr> but i've be proven wrong many times, so ..
+    <braunr> there are two main facts that lead me to think this
+    <braunr> 1/
+      http://www.gnu.org/software/hurd/gnumach-doc/Memory-Objects-and-Data.html#Memory-Objects-and-Data
+      says lengths are provided and doesn't mention the limitation
+    <braunr> 2/ when reading about UVM, one of the major improvements (between
+      10 and 30% of global performance depending on the benchmarks) was
+      implementing the madvise semantics
+    <braunr> and this didn't involve a new pager interface, but rather a new
+      page fault handler
+    <antrik> braunr: hm... the interface indeed looks like it can handle
+      multiple pages in both directions... perhaps it was at the Hurd level
+      where the pager interface needs to be modified, not the Mach one?...
+    <braunr> antrik: would be nice wouldn't it ? :)
+    <braunr> antrik: more probably the page fault handler