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# HG changeset 42+74 patch
# User kfraser@localhost.localdomain
# Date 1181573766 -3600
# Node ID c09686d2bbffa5ec2152f685df0eaa090ddddd83
# Parent 07a5f92187ac57ffbd107571b2019be2f53bda98
Subject: Kernel threads need to be aware of freeze request,
by checking in their main loop.
xenbus/xenwatch threads are special with PF_NOFREEZE, since we're sure
that they do nothing to block other native device drivers.
Signed-off-by Ke Yu <ke.yu@intel.com>
Signed-off-by Kevin Tian <kevin.tian@intel.com>
blktap: blktap kthread must respond to freeze requests.
Signed-off-by: Keir Fraser <keir@xensource.com>
Acked-by: jbeulich@novell.com
---
drivers/xen/blkback/blkback.c | 3 +++
drivers/xen/blktap/blktap.c | 3 +++
drivers/xen/xenbus/xenbus_xs.c | 2 ++
3 files changed, 8 insertions(+)
--- a/drivers/xen/blkback/blkback.c 2007-08-27 14:01:25.000000000 -0400
+++ b/drivers/xen/blkback/blkback.c 2007-08-27 14:02:03.000000000 -0400
@@ -208,6 +208,9 @@ int blkif_schedule(void *arg)
printk(KERN_DEBUG "%s: started\n", current->comm);
while (!kthread_should_stop()) {
+ if (try_to_freeze())
+ continue;
+
wait_event_interruptible(
blkif->wq,
blkif->waiting_reqs || kthread_should_stop());
--- a/drivers/xen/blktap/blktap.c 2007-08-27 14:01:25.000000000 -0400
+++ b/drivers/xen/blktap/blktap.c 2007-08-27 14:02:03.000000000 -0400
@@ -942,6 +942,9 @@ int tap_blkif_schedule(void *arg)
printk(KERN_DEBUG "%s: started\n", current->comm);
while (!kthread_should_stop()) {
+ if (try_to_freeze())
+ continue;
+
wait_event_interruptible(
blkif->wq,
blkif->waiting_reqs || kthread_should_stop());
--- a/drivers/xen/xenbus/xenbus_xs.c 2007-08-27 14:01:25.000000000 -0400
+++ b/drivers/xen/xenbus/xenbus_xs.c 2007-08-27 14:01:25.000000000 -0400
@@ -718,6 +718,7 @@ static int xenwatch_thread(void *unused)
struct list_head *ent;
struct xs_stored_msg *msg;
+ current->flags |= PF_NOFREEZE;
for (;;) {
wait_event_interruptible(watch_events_waitq,
!list_empty(&watch_events));
@@ -836,6 +837,7 @@ static int xenbus_thread(void *unused)
{
int err;
+ current->flags |= PF_NOFREEZE;
for (;;) {
err = process_msg();
if (err)
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