[PATCH v2 5/5] PM / sleep: Asynchronous threads for suspend_late

From: Chuansheng Liu
Date: Mon Feb 17 2014 - 00:54:09 EST


In analogy with commits 5af84b82701a and 97df8c12995, using
asynchronous threads can improve the overall suspend_late
time significantly.

This patch is for suspend_late phase.

Signed-off-by: Chuansheng Liu <chuansheng.liu@xxxxxxxxx>
---
drivers/base/power/main.c | 64 ++++++++++++++++++++++++++++++++++++++---------
1 file changed, 52 insertions(+), 12 deletions(-)

diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index 72b4c9c..0c5fad0 100644
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -1127,16 +1127,24 @@ static int dpm_suspend_noirq(pm_message_t state)
*
* Runtime PM is disabled for @dev while this function is being executed.
*/
-static int device_suspend_late(struct device *dev, pm_message_t state)
+static int __device_suspend_late(struct device *dev, pm_message_t state, bool async)
{
pm_callback_t callback = NULL;
char *info = NULL;
- int error;
+ int error = 0;

__pm_runtime_disable(dev, false);

+ if (async_error)
+ goto Complete;
+
+ if (pm_wakeup_pending()) {
+ async_error = -EBUSY;
+ goto Complete;
+ }
+
if (dev->power.syscore)
- return 0;
+ goto Complete;

if (dev->pm_domain) {
info = "late power domain ";
@@ -1160,10 +1168,40 @@ static int device_suspend_late(struct device *dev, pm_message_t state)
error = dpm_run_callback(callback, dev, state, info);
if (!error)
dev->power.is_late_suspended = true;
+ else
+ async_error = error;

+Complete:
+ complete_all(&dev->power.completion);
return error;
}

+static void async_suspend_late(void *data, async_cookie_t cookie)
+{
+ struct device *dev = (struct device *)data;
+ int error;
+
+ error = __device_suspend_late(dev, pm_transition, true);
+ if (error) {
+ dpm_save_failed_dev(dev_name(dev));
+ pm_dev_err(dev, pm_transition, " async", error);
+ }
+ put_device(dev);
+}
+
+static int device_suspend_late(struct device *dev)
+{
+ reinit_completion(&dev->power.completion);
+
+ if (pm_async_enabled && dev->power.async_suspend) {
+ get_device(dev);
+ async_schedule(async_suspend_late, dev);
+ return 0;
+ }
+
+ return __device_suspend_late(dev, pm_transition, false);
+}
+
/**
* dpm_suspend_late - Execute "late suspend" callbacks for all devices.
* @state: PM transition of the system being carried out.
@@ -1174,19 +1212,20 @@ static int dpm_suspend_late(pm_message_t state)
int error = 0;

mutex_lock(&dpm_list_mtx);
+ pm_transition = state;
+ async_error = 0;
+
while (!list_empty(&dpm_suspended_list)) {
struct device *dev = to_device(dpm_suspended_list.prev);

get_device(dev);
mutex_unlock(&dpm_list_mtx);

- error = device_suspend_late(dev, state);
+ error = device_suspend_late(dev);

mutex_lock(&dpm_list_mtx);
if (error) {
pm_dev_err(dev, state, " late", error);
- suspend_stats.failed_suspend_late++;
- dpm_save_failed_step(SUSPEND_SUSPEND_LATE);
dpm_save_failed_dev(dev_name(dev));
put_device(dev);
break;
@@ -1195,17 +1234,18 @@ static int dpm_suspend_late(pm_message_t state)
list_move(&dev->power.entry, &dpm_late_early_list);
put_device(dev);

- if (pm_wakeup_pending()) {
- error = -EBUSY;
+ if (async_error)
break;
- }
}
mutex_unlock(&dpm_list_mtx);
- if (error)
+ async_synchronize_full();
+ if (error) {
+ suspend_stats.failed_suspend_late++;
+ dpm_save_failed_step(SUSPEND_SUSPEND_LATE);
dpm_resume_early(resume_event(state));
- else
+ } else {
dpm_show_time(starttime, state, "late");
-
+ }
return error;
}

--
1.9.rc0

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/