Mailing List Archive

# HG changeset patch
# User Keir Fraser <keir@xen.org>
# Date 1293179367 0
# Node ID 597e3fee23bceb489fbab4aea3c74e32c369e2ba
# Parent 3e7702cb31dbc72d88d894d443088f55b3119e9d
credit2: Detect socket layout and assign one runqueue per socket

Because alloc_pdata() is called before the cpu layout information is
available, we grab a callback to the newly-created CPU_STARTING
notifier.

cpu 0 doesn't get a callback, so we simply hard-code it to runqueue 0.

Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com>
---
xen/common/sched_credit2.c | 69 +++++++++++++++++++++++++++++++++++++++++++--
1 files changed, 66 insertions(+), 3 deletions(-)

diff -r 3e7702cb31db -r 597e3fee23bc xen/common/sched_credit2.c
--- a/xen/common/sched_credit2.c Fri Dec 24 08:29:00 2010 +0000
+++ b/xen/common/sched_credit2.c Fri Dec 24 08:29:27 2010 +0000
@@ -24,6 +24,7 @@
#include <asm/atomic.h>
#include <xen/errno.h>
#include <xen/trace.h>
+#include <xen/cpu.h>

#if __i386__
#define PRI_stime "lld"
@@ -712,13 +713,15 @@ csched_vcpu_insert(const struct schedule
printk("%s: Inserting d%dv%d\n",
__func__, dom->domain_id, vc->vcpu_id);

+ /* NB: On boot, idle vcpus are inserted before alloc_pdata() has
+ * been called for that cpu.
+ */
if ( ! is_idle_vcpu(vc) )
{
/* FIXME: Do we need the private lock here? */
list_add_tail(&svc->sdom_elem, &svc->sdom->vcpu);

/* Add vcpu to runqueue of initial processor */
- /* FIXME: Abstract for multiple runqueues */
vcpu_schedule_lock_irq(vc);

runq_assign(ops, vc);
@@ -1462,6 +1465,20 @@ static void init_pcpu(const struct sched
/* Figure out which runqueue to put it in */
rqi = 0;

+ /* Figure out which runqueue to put it in */
+ /* NB: cpu 0 doesn't get a STARTING callback, so we hard-code it to runqueue 0. */
+ if ( cpu == 0 )
+ rqi = 0;
+ else
+ rqi = cpu_to_socket(cpu);
+
+ if ( rqi < 0 )
+ {
+ printk("%s: cpu_to_socket(%d) returned %d!\n",
+ __func__, cpu, rqi);
+ BUG();
+ }
+
rqd=prv->rqd + rqi;

printk("Adding cpu %d to runqueue %d\n", cpu, rqi);
@@ -1495,7 +1512,13 @@ static void *
static void *
csched_alloc_pdata(const struct scheduler *ops, int cpu)
{
- init_pcpu(ops, cpu);
+ /* Check to see if the cpu is online yet */
+ /* Note: cpu 0 doesn't get a STARTING callback */
+ if ( cpu == 0 || cpu_to_socket(cpu) >= 0 )
+ init_pcpu(ops, cpu);
+ else
+ printk("%s: cpu %d not online yet, deferring initializatgion\n",
+ __func__, cpu);

return (void *)1;
}
@@ -1543,6 +1566,41 @@ csched_free_pdata(const struct scheduler
}

static int
+csched_cpu_starting(int cpu)
+{
+ struct scheduler *ops;
+
+ /* Hope this is safe from cpupools switching things around. :-) */
+ ops = per_cpu(scheduler, cpu);
+
+ init_pcpu(ops, cpu);
+
+ return NOTIFY_DONE;
+}
+
+static int cpu_credit2_callback(
+ struct notifier_block *nfb, unsigned long action, void *hcpu)
+{
+ unsigned int cpu = (unsigned long)hcpu;
+ int rc = 0;
+
+ switch ( action )
+ {
+ case CPU_STARTING:
+ csched_cpu_starting(cpu);
+ break;
+ default:
+ break;
+ }
+
+ return !rc ? NOTIFY_DONE : notifier_from_errno(rc);
+}
+
+static struct notifier_block cpu_credit2_nfb = {
+ .notifier_call = cpu_credit2_callback
+};
+
+static int
csched_init(struct scheduler *ops)
{
int i;
@@ -1551,15 +1609,20 @@ csched_init(struct scheduler *ops)
printk("Initializing Credit2 scheduler\n" \
" WARNING: This is experimental software in development.\n" \
" Use at your own risk.\n");
+
+ /* Basically no CPU information is available at this point; just
+ * set up basic structures, and a callback when the CPU info is
+ * available. */

prv = xmalloc(struct csched_private);
if ( prv == NULL )
return -ENOMEM;
memset(prv, 0, sizeof(*prv));
ops->sched_data = prv;
-
spin_lock_init(&prv->lock);
INIT_LIST_HEAD(&prv->sdom);
+
+ register_cpu_notifier(&cpu_credit2_nfb);

/* But un-initialize all runqueues */
for ( i=0; i<NR_CPUS; i++)

_______________________________________________
Xen-changelog mailing list
Xen-changelog@lists.xensource.com
http://lists.xensource.com/xen-changelog