Mailing List Archive

# HG changeset patch
# User Keir Fraser <keir.fraser@citrix.com>
# Date 1273650430 -3600
# Node ID 94fe56ff92be33eb9dd5181f88fd69f7fc1040b3
# Parent 15e574a858000a721d962a6f3152ab561f11f5c1
credit2: Fix tasklets

Signed-off-by: George Dunlap <George.Dunlap@eu.citrix.com>
---
xen/common/sched_credit2.c | 22 ++++++++++------------
1 files changed, 10 insertions(+), 12 deletions(-)

diff -r 15e574a85800 -r 94fe56ff92be xen/common/sched_credit2.c
--- a/xen/common/sched_credit2.c Wed May 12 08:43:47 2010 +0100
+++ b/xen/common/sched_credit2.c Wed May 12 08:47:10 2010 +0100
@@ -921,18 +921,16 @@ csched_schedule(
/* Update credits */
burn_credits(rqd, scurr, now);

- /* Tasklet work (which runs in idle VCPU context) overrides all else. */
- if ( tasklet_work_scheduled )
- {
- snext = CSCHED_VCPU(idle_vcpu[cpu]);
- goto out;
- }
-
/*
* Select next runnable local VCPU (ie top of local runq).
*
* If the current vcpu is runnable, and has higher credit than
- * the next guy on the queue (or there is noone else), we want to run him again.
+ * the next guy on the queue (or there is noone else), we want to
+ * run him again.
+ *
+ * If there's tasklet work to do, we want to chose the idle vcpu
+ * for this processor, and mark the current for delayed runqueue
+ * add.
*
* If the current vcpu is runnable, and the next guy on the queue
* has higher credit, we want to mark current for delayed runqueue
@@ -941,7 +939,7 @@ csched_schedule(
* If the current vcpu is not runnable, we want to chose the idle
* vcpu for this processor.
*/
- if ( list_empty(runq) )
+ if ( list_empty(runq) || tasklet_work_scheduled )
snext = CSCHED_VCPU(idle_vcpu[cpu]);
else
snext = __runq_elem(runq->next);
@@ -949,9 +947,10 @@ csched_schedule(
if ( !is_idle_vcpu(current) && vcpu_runnable(current) )
{
/* If the current vcpu is runnable, and has higher credit
- * than the next on the runqueue, run him again.
+ * than the next on the runqueue, and isn't being preempted
+ * by a tasklet, run him again.
* Otherwise, set him for delayed runq add. */
- if ( scurr->credit > snext->credit)
+ if ( !tasklet_work_scheduled && scurr->credit > snext->credit)
snext = scurr;
else
set_bit(__CSFLAG_delayed_runq_add, &scurr->flags);
@@ -998,7 +997,6 @@ csched_schedule(
snext->vcpu->processor = cpu; /* Safe because lock for old processor is held */
}

- out:
/*
* Return task to run next...
*/

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