Replace my previous patch with equivalent fix from linux-2.6.17.

Might as well stay as close to that as we can...
Signed-off-by: Emmanuel Ackaouy <ack@xensource.com>

1 files changed, 18 insertions, 14 deletions

diff --git a/patches/linux-2.6.16.13/fix-hz-suspend.patch b/patches/linux-2.6.16.13/fix-hz-suspend.patch
index a90c30816a..bcb79553e7 100644
--- a/patches/linux-2.6.16.13/fix-hz-suspend.patch
+++ b/patches/linux-2.6.16.13/fix-hz-suspend.patch
@@ -1,22 +1,26 @@
 diff -pruN ../pristine-linux-2.6.16.13/kernel/timer.c ./kernel/timer.c
---- ../pristine-linux-2.6.16.13/kernel/timer.c	2006-05-02 14:38:44.000000000 -0700
-+++ ./kernel/timer.c	2006-06-28 09:57:51.000000000 -0700
-@@ -555,7 +555,17 @@ found:
+--- ../pristine-linux-2.6.16.13/kernel/timer.c	2006-05-02 22:38:44.000000000 +0100
++++ ./kernel/timer.c	2006-06-29 14:34:12.788957720 +0100
+@@ -555,6 +555,22 @@ found:
  	}
  	spin_unlock(&base->t_base.lock);
  
--	if (time_before(hr_expires, expires))
 +	/*
-+	 * If timers are pending, "expires" will be in the recent past
-+	 * of "jiffies". If there are no hr_timers registered, "hr_expires"
-+	 * will be "jiffies + MAX_JIFFY_OFFSET"; this is *just* short of being
-+	 * considered to be before "jiffies". This makes it very likely that
-+	 * "hr_expires" *will* be considered to be before "expires".
-+	 * So we must check when there are pending timers (expires <= jiffies)
-+	 * to ensure that we don't accidently tell the caller that there is
-+	 * nothing scheduled until half an epoch (MAX_JIFFY_OFFSET)!
++	 * It can happen that other CPUs service timer IRQs and increment
++	 * jiffies, but we have not yet got a local timer tick to process
++	 * the timer wheels.  In that case, the expiry time can be before
++	 * jiffies, but since the high-resolution timer here is relative to
++	 * jiffies, the default expression when high-resolution timers are
++	 * not active,
++	 *
++	 *   time_before(MAX_JIFFY_OFFSET + jiffies, expires)
++	 *
++	 * would falsely evaluate to true.  If that is the case, just
++	 * return jiffies so that we can immediately fire the local timer
 +	 */
-+	if (time_before(jiffies, expires) && time_before(hr_expires, expires))
++	if (time_before(expires, jiffies))
++		return jiffies;
++
+ 	if (time_before(hr_expires, expires))
  		return hr_expires;
  
- 	return expires;