[Libguestfs] [PATCH] Use the noop scheduler inside the appliance.
Richard W.M. Jones
rjones at redhat.com
Mon Jun 7 14:33:57 UTC 2010
The Wikipedia pages about schedulers are quite informative. I don't
know _why_ this makes a difference, but it does seem to make a small
one. Even though for a single process (guestfsd) it would seem that
the choice of scheduler should make no difference.
BTW the default scheduler in the guest is 'cfq'.
http://en.wikipedia.org/wiki/Noop_scheduler
http://en.wikipedia.org/wiki/CFQ
Rich.
--
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>From 1253f577fa162b9170b22f3c543167aa99795920 Mon Sep 17 00:00:00 2001
From: Richard Jones <rjones at redhat.com>
Date: Mon, 7 Jun 2010 15:29:31 +0100
Subject: [PATCH] Use the noop scheduler inside the appliance.
In my limited tests, this seems to make a small but noticable
difference, improving the performance of some straightforward
read operations by a little over 10%.
For more information see:
http://kbase.redhat.com/faq/docs/DOC-5428
---
appliance/init | 3 +++
1 files changed, 3 insertions(+), 0 deletions(-)
diff --git a/appliance/init b/appliance/init
index c622788..b8133ca 100755
--- a/appliance/init
+++ b/appliance/init
@@ -66,6 +66,9 @@ lvm vgchange -ay --ignorelockingfailure
# Improve virtio-blk performance (RHBZ#509383).
for f in /sys/block/vd*/queue/rotational; do echo 1 > $f; done
+# http://kbase.redhat.com/faq/docs/DOC-5428
+for f in /sys/block/[hsv]d*/queue/scheduler; do echo noop > $f; done
+
# Keep these to enhance the usefulness of debug output.
ls -l /dev
cat /proc/mounts
--
1.6.6.1
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