When the suspend process is executed from the /sys/power/state entry,
the pm_wakeup_clear() signal is cleared in advance, and the wakeup
signal can be captured to fail the suspend process when the suspend
process is notified by the notifier;
Expanding the scope of the pm_suspend_target_state variable also allows
the device driver to know that the system has entered the suspend
process earlier.
xiongxin (2):
PM: suspend: expand the assignment scope of the
pm_suspend_target_state
PM: suspend: advanced pm_wakeup_clear() for normal suspend/hibernate
kernel/power/process.c | 5 ++++-
kernel/power/suspend.c | 13 +++++++++++++
2 files changed, 17 insertions(+), 1 deletion(-)
--
2.25.1
No virus found
Checked by Hillstone Network AntiVirus
The pm_suspend_target_state variable can be used as a suspend state
identifier and given to the specific device driver as a code judgment;
Because the suspend_prepare() function is time-consuming for the
operation of freezing processes, and this stage is actually in the suspend
stage, it is necessary to expand the scope of the pm_suspend_target_state
variable to be assigned to the suspend state at enter_state() function;
Another reason is that the specific device driver can locate whether it is
in the suspend state based on this variable, so as to determine the
validity of its wake-up source.
Signed-off-by: xiongxin <[email protected]>
---
kernel/power/suspend.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index 827075944d28..c754b084ec03 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -564,6 +564,12 @@ static int enter_state(suspend_state_t state)
if (state == PM_SUSPEND_TO_IDLE)
s2idle_begin();
+ /*
+ * Expand the scope of suspend state for suspend operations
+ * performed from the /sys/power/state entry.
+ */
+ pm_suspend_target_state = state;
+
if (sync_on_suspend_enabled) {
trace_suspend_resume(TPS("sync_filesystems"), 0, true);
ksys_sync_helper();
@@ -590,6 +596,7 @@ static int enter_state(suspend_state_t state)
pm_pr_dbg("Finishing wakeup.\n");
suspend_finish();
Unlock:
+ pm_suspend_target_state = PM_SUSPEND_ON;
mutex_unlock(&system_transition_mutex);
return error;
}
--
2.25.1
No virus found
Checked by Hillstone Network AntiVirus
pm_wakeup_clear() will clear the wakeup source, which can ensure that it
is not disturbed by useless wakeup signals when doing suspend/hibernate;
At the beginning of the suspend/hibernate process, the notifier
mechanism is used to notify other device drivers. This action is
time-consuming (second-level time-consuming). If the process fails due
to the received wakeup signal during the execution of these functions,
it can better improve the experience of failing suspend/hibernate
returns;
Therefore, it is recommended here that for the suspend/hibernate process
normally called from /sys/power/state, the pm_wakeup_clear() function
should be brought before the notifier call; for the freeze_process()
function called from other places, the original logic is kept;
The pm_suspend_target_state variable is used here to identify whether the
suspend process is going normally.
Signed-off-by: xiongxin <[email protected]>
---
kernel/power/process.c | 5 ++++-
kernel/power/suspend.c | 6 ++++++
2 files changed, 10 insertions(+), 1 deletion(-)
diff --git a/kernel/power/process.c b/kernel/power/process.c
index 3068601e585a..3fde0240b3d1 100644
--- a/kernel/power/process.c
+++ b/kernel/power/process.c
@@ -131,7 +131,10 @@ int freeze_processes(void)
if (!pm_freezing)
atomic_inc(&system_freezing_cnt);
- pm_wakeup_clear(0);
+ if (pm_suspend_target_state != PM_SUSPEND_ON)
+ pm_wakeup_clear(1);
+ else
+ pm_wakeup_clear(0);
pr_info("Freezing user space processes ... ");
pm_freezing = true;
error = try_to_freeze_tasks(true);
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index c754b084ec03..f4259f6c1cc2 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -569,6 +569,12 @@ static int enter_state(suspend_state_t state)
* performed from the /sys/power/state entry.
*/
pm_suspend_target_state = state;
+ /*
+ * Put pm_wakeup_clear() before the notifier notification chain to
+ * optimize in the suspend process, the wakeup signal can interrupt
+ * the suspend in advance and fail to return.
+ */
+ pm_wakeup_clear(0);
if (sync_on_suspend_enabled) {
trace_suspend_resume(TPS("sync_filesystems"), 0, true);
--
2.25.1
No virus found
Checked by Hillstone Network AntiVirus
Hi xiongxin,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on next-20220628]
url: https://github.com/intel-lab-lkp/linux/commits/xiongxin/PM-suspend-Optimized-suspend-is-fail-returned-by-wakeup/20220629-114731
base: cb71b93c2dc36d18a8b05245973328d018272cdf
config: sh-allmodconfig (https://download.01.org/0day-ci/archive/20220629/[email protected]/config)
compiler: sh4-linux-gcc (GCC) 11.3.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/intel-lab-lkp/linux/commit/2e0bc447b95996d1757038708bd6adf613f0b936
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review xiongxin/PM-suspend-Optimized-suspend-is-fail-returned-by-wakeup/20220629-114731
git checkout 2e0bc447b95996d1757038708bd6adf613f0b936
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.3.0 make.cross W=1 O=build_dir ARCH=sh SHELL=/bin/bash
If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <[email protected]>
All errors (new ones prefixed by >>):
kernel/power/process.c: In function 'freeze_processes':
>> kernel/power/process.c:134:13: error: 'pm_suspend_target_state' undeclared (first use in this function)
134 | if (pm_suspend_target_state != PM_SUSPEND_ON)
| ^~~~~~~~~~~~~~~~~~~~~~~
kernel/power/process.c:134:13: note: each undeclared identifier is reported only once for each function it appears in
vim +/pm_suspend_target_state +134 kernel/power/process.c
112
113 /**
114 * freeze_processes - Signal user space processes to enter the refrigerator.
115 * The current thread will not be frozen. The same process that calls
116 * freeze_processes must later call thaw_processes.
117 *
118 * On success, returns 0. On failure, -errno and system is fully thawed.
119 */
120 int freeze_processes(void)
121 {
122 int error;
123
124 error = __usermodehelper_disable(UMH_FREEZING);
125 if (error)
126 return error;
127
128 /* Make sure this task doesn't get frozen */
129 current->flags |= PF_SUSPEND_TASK;
130
131 if (!pm_freezing)
132 atomic_inc(&system_freezing_cnt);
133
> 134 if (pm_suspend_target_state != PM_SUSPEND_ON)
135 pm_wakeup_clear(1);
136 else
137 pm_wakeup_clear(0);
138 pr_info("Freezing user space processes ... ");
139 pm_freezing = true;
140 error = try_to_freeze_tasks(true);
141 if (!error) {
142 __usermodehelper_set_disable_depth(UMH_DISABLED);
143 pr_cont("done.");
144 }
145 pr_cont("\n");
146 BUG_ON(in_atomic());
147
148 /*
149 * Now that the whole userspace is frozen we need to disable
150 * the OOM killer to disallow any further interference with
151 * killable tasks. There is no guarantee oom victims will
152 * ever reach a point they go away we have to wait with a timeout.
153 */
154 if (!error && !oom_killer_disable(msecs_to_jiffies(freeze_timeout_msecs)))
155 error = -EBUSY;
156
157 if (error)
158 thaw_processes();
159 return error;
160 }
161
--
0-DAY CI Kernel Test Service
https://01.org/lkp