IRC.

3 files changed, 72 insertions, 4 deletions

diff --git a/open_issues/performance/degradation.mdwn b/open_issues/performance/degradation.mdwn
index db759308..8c9a087c 100644
--- a/open_issues/performance/degradation.mdwn
+++ b/open_issues/performance/degradation.mdwn
@@ -10,8 +10,12 @@ License|/fdl]]."]]"""]]
 
 [[!meta title="Degradation of GNU/Hurd ``system performance''"]]
 
-Email, *id:"87mxg2ahh8.fsf@kepler.schwinge.homeip.net"* (bug-hurd, 2011-07-25,
-Thomas Schwinge)
+[[!tag open_issue_gnumach open_issue_hurd]]
+
+[[!toc]]
+
+
+# Email, `id:"87mxg2ahh8.fsf@kepler.schwinge.homeip.net"` (bug-hurd, 2011-07-25, Thomas Schwinge)
 
 > Building a certain GCC configuration on a freshly booted system: 11 h.
 > Remove build tree, build it again (2nd): 12 h 50 min.  Huh.  Remove build
@@ -27,9 +31,8 @@ IRC, freenode, #hurd, 2011-07-23:
       are some serious fragmentation issues
     < braunr> antrik: both could be induced by fragmentation
 
----
 
-During [[IPC_virtual_copy]] testing:
+# During [[IPC_virtual_copy]] testing
 
 IRC, freenode, #hurd, 2011-09-02:
 
@@ -38,3 +41,8 @@ IRC, freenode, #hurd, 2011-09-02:
       800 fifteen minutes ago)
     <braunr> manuel: i observed the same behaviour
     [...]
+
+
+# IRC, freenode, #hurd, 2011-09-22
+
+See [[/open_issues/pagers]], IRC, freenode, #hurd, 2011-09-22.
diff --git a/open_issues/performance/io_system/clustered_page_faults.mdwn b/open_issues/performance/io_system/clustered_page_faults.mdwn
index 9e20f8e1..a3baf30d 100644
--- a/open_issues/performance/io_system/clustered_page_faults.mdwn
+++ b/open_issues/performance/io_system/clustered_page_faults.mdwn
@@ -137,3 +137,26 @@ License|/fdl]]."]]"""]]
       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
+
+
+# IRC, freenode, #hurd, 2011-09-28
+
+    <slpz> antrik: I've just recovered part of my old multipage I/O work
+    <slpz> antrik: I intend to clean and submit it after finishing the changes
+      to the pageout system.
+    <antrik> slpz: oh, great!
+    <antrik> didn't know you worked on multipage I/O
+    <antrik> slpz: BTW, have you checked whether any of the work done for GSoC
+      last year is any good?...
+    <antrik> (apart from missing copyright assignments, which would be a
+      serious problem for the Hurd parts...)
+    <slpz> antrik: It was seven years ago, but I did:
+      http://www.mail-archive.com/bug-hurd@gnu.org/msg10285.html :-)
+    <slpz> antrik: Sincerely, I don't think the quality of that code is good
+      enough to be considered... but I think it was my fault as his mentor for
+      not correcting him soon enough...
+    <antrik> slpz: I see
+    <antrik> TBH, I feel guilty myself, for not asking about the situation
+      immediately when he stopped attending meetings...
+    <antrik> slpz: oh, you even already looked into vm_pageout_scan() back then
+      :-)
diff --git a/open_issues/performance/ipc_virtual_copy.mdwn b/open_issues/performance/ipc_virtual_copy.mdwn
index 00fa7180..9708ab96 100644
--- a/open_issues/performance/ipc_virtual_copy.mdwn
+++ b/open_issues/performance/ipc_virtual_copy.mdwn
@@ -356,3 +356,40 @@ IRC, freenode, #hurd, 2011-09-06:
     <youpi> in PV it does not make sense: the guest already provides the
       translated page table
     <youpi> which is just faster than anything else
+
+IRC, freenode, #hurd, 2011-09-09:
+
+    <antrik> oh BTW, for another data point: dd zero->null gets around 225 MB/s
+      on my lowly 1 GHz Pentium3, with a blocksize of 32k
+    <antrik> (but only half of that with 256k blocksize, and even less with 1M)
+    <antrik> the system has been up for a while... don't know whether it's
+      faster on a freshly booted one
+
+IRC, freenode, #hurd, 2011-09-15:
+
+    <sudoman>
+      http://www.reddit.com/r/gnu/comments/k68mb/how_intelamd_inadvertently_fixed_gnu_hurd/
+    <sudoman> so is the dd command pointed to by that article a measure of io
+      performance?
+    <antrik> sudoman: no, not really
+    <antrik> it's basically the baseline of what is possible -- but the actual
+      slowness we experience is more due to very unoptimal disk access patterns
+    <antrik> though using KVM with writeback caching does actually help with
+      that...
+    <antrik> also note that the title of this post really makes no
+      sense... nested page tables should provide similar improvements for *any*
+      guest system doing VM manipulation -- it's not Hurd-specific at all
+    <sudoman> ok, that makes sense. thanks :)
+
+IRC, freenode, #hurd, 2011-09-16:
+
+    <slpz> antrik: I wrote that article (the one about How AMD/Intel fixed...)
+    <slpz> antrik: It's obviously a bit of an exaggeration, but it's true that
+      nested pages supposes a great improvement in the performance of Hurd
+      running on virtual machines
+    <slpz> antrik: and it's Hurd specific, as this system is more affected by
+      the cost of page faults
+    <slpz> antrik: and as the impact of virtualization on the performance is
+      much higher than (almost) any other OS.
+    <slpz> antrik: also, dd from /dev/zero to /dev/null it's a measure on how
+      fast OOL IPC is.