[PATCH] PM / suspend: show workqueue state in suspend flow

From: Roger Lu
Date: Wed Jun 29 2016 - 23:20:26 EST


If freezable workqueue aborts suspend flow, show
workqueue state for debug purpose.

Signed-off-by: Roger Lu <roger.lu@xxxxxxxxxxxx>
---
kernel/power/process.c | 3 +++
kernel/workqueue.c | 7 +++++--
2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/kernel/power/process.c b/kernel/power/process.c
index df058be..6eef250 100644
--- a/kernel/power/process.c
+++ b/kernel/power/process.c
@@ -89,6 +89,9 @@ static int try_to_freeze_tasks(bool user_only)
elapsed_msecs / 1000, elapsed_msecs % 1000,
todo - wq_busy, wq_busy);

+ if (wq_busy)
+ show_workqueue_state();
+
if (!wakeup) {
read_lock(&tasklist_lock);
for_each_process_thread(g, p) {
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index e1c0e99..c945617 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -4369,8 +4369,8 @@ static void show_pwq(struct pool_workqueue *pwq)
/**
* show_workqueue_state - dump workqueue state
*
- * Called from a sysrq handler and prints out all busy workqueues and
- * pools.
+ * Called from a sysrq handler or try_to_freeze_tasks() and prints out
+ * all busy workqueues and pools.
*/
void show_workqueue_state(void)
{
@@ -4396,6 +4396,9 @@ void show_workqueue_state(void)
if (idle)
continue;

+ if (wq->flags & WQ_FREEZABLE)
+ pr_info("freezable ");
+
pr_info("workqueue %s: flags=0x%x\n", wq->name, wq->flags);

for_each_pwq(pwq, wq) {
--
2.6.4