A freezable kernel thread can enter frozen state during freezing by
either calling try_to_freeze() or using wait_event_freezable() and its
variants. So for the following snippet of code in a kernel thread loop:
try_to_freeze();
wait_event_interruptible();
We can change it to a simple wait_event_freezable() and then eliminate
a function call.
Signed-off-by: Kevin Hao <haokexin@xxxxxxxxx>
---
drivers/block/xen-blkback/blkback.c | 10 ++++------
1 file changed, 4 insertions(+), 6 deletions(-)
diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c
index 4defd7f387c7..bef0f950b257 100644
--- a/drivers/block/xen-blkback/blkback.c
+++ b/drivers/block/xen-blkback/blkback.c
@@ -563,20 +563,18 @@ int xen_blkif_schedule(void *arg)
set_freezable();
while (!kthread_should_stop()) {
- if (try_to_freeze())
- continue;
if (unlikely(vbd->size != vbd_sz(vbd)))
xen_vbd_resize(blkif);
timeout = msecs_to_jiffies(LRU_INTERVAL);
- timeout = wait_event_interruptible_timeout(
+ timeout = wait_event_freezable_timeout(
ring->wq,
ring->waiting_reqs || kthread_should_stop(),
timeout);
if (timeout == 0)
goto purge_gnt_list;
- timeout = wait_event_interruptible_timeout(
+ timeout = wait_event_freezable_timeout(
ring->pending_free_wq,
!list_empty(&ring->pending_free) ||
kthread_should_stop(),
@@ -593,8 +591,8 @@ int xen_blkif_schedule(void *arg)
if (ret > 0)
ring->waiting_reqs = 1;
if (ret == -EACCES)
- wait_event_interruptible(ring->shutdown_wq,
- kthread_should_stop());
+ wait_event_freezable(ring->shutdown_wq,
+ kthread_should_stop());
if (do_eoi && !ring->waiting_reqs) {
xen_irq_lateeoi(ring->irq, eoi_flags);
--
2.39.2
