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Message-ID: <CAJFUiJhemGu=PcbUoQH_B7VreRprK28F-qemGzyJjYLveZewbg@mail.gmail.com>
Date: Fri, 10 Jun 2016 23:23:31 -0700
From: Lianwei Wang <lianwei.wang@...il.com>
To: "Rafael J. Wysocki" <rjw@...ysocki.net>
Cc: Thomas Gleixner <tglx@...utronix.de>,
Peter Zijlstra <peterz@...radead.org>,
Ingo Molnar <mingo@...nel.org>,
Oleg Nesterov <oleg@...hat.com>,
Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
linux-pm@...r.kernel.org
Subject: Re: [PATCH v1] PM / sleep: make pm notifier called symmetrically
On Fri, Jun 10, 2016 at 7:00 AM, Rafael J. Wysocki <rjw@...ysocki.net> wrote:
> On Thursday, June 09, 2016 11:47:32 PM Lianwei Wang wrote:
>> This makes pm notifier PREPARE/POST symmetrical: if PREPARE
>> fails, we will only undo what ever happened on PREPARE.
>>
>> It fixes the unbalanced cpu hotplug enable in cpu pm notifier.
>>
>> Signed-off-by: Lianwei Wang <lianwei.wang@...il.com>
>
> Did you fix the build issue with the previous iteration reported by 0-day?
>
Yes. I had fix the build issue.
>> ---
>> kernel/power/hibernate.c | 20 ++++++++++++--------
>> kernel/power/main.c | 11 +++++++++--
>> kernel/power/power.h | 2 ++
>> kernel/power/suspend.c | 10 ++++++----
>> kernel/power/user.c | 18 ++++++++++++------
>> 5 files changed, 41 insertions(+), 20 deletions(-)
>>
>> diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
>> index fca9254280ee..126e24caa82e 100644
>> --- a/kernel/power/hibernate.c
>> +++ b/kernel/power/hibernate.c
>> @@ -647,7 +647,7 @@ static void power_down(void)
>> */
>> int hibernate(void)
>> {
>> - int error;
>> + int error, nr_calls = 0;
>>
>> if (!hibernation_available()) {
>> pr_debug("PM: Hibernation not available.\n");
>> @@ -662,9 +662,11 @@ int hibernate(void)
>> }
>>
>> pm_prepare_console();
>> - error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
>> - if (error)
>> + error = __pm_notifier_call_chain(PM_HIBERNATION_PREPARE, -1, &nr_calls);
>> + if (error) {
>> + nr_calls--;
>> goto Exit;
>> + }
>>
>> printk(KERN_INFO "PM: Syncing filesystems ... ");
>> sys_sync();
>> @@ -714,7 +716,7 @@ int hibernate(void)
>> /* Don't bother checking whether freezer_test_done is true */
>> freezer_test_done = false;
>> Exit:
>> - pm_notifier_call_chain(PM_POST_HIBERNATION);
>> + __pm_notifier_call_chain(PM_POST_HIBERNATION, nr_calls, NULL);
>> pm_restore_console();
>> atomic_inc(&snapshot_device_available);
>> Unlock:
>> @@ -740,7 +742,7 @@ int hibernate(void)
>> */
>> static int software_resume(void)
>> {
>> - int error;
>> + int error, nr_calls = 0;
>> unsigned int flags;
>>
>> /*
>> @@ -827,9 +829,11 @@ static int software_resume(void)
>> }
>>
>> pm_prepare_console();
>> - error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
>> - if (error)
>> + error = __pm_notifier_call_chain(PM_RESTORE_PREPARE, -1, &nr_calls);
>> + if (error) {
>> + nr_calls--;
>> goto Close_Finish;
>> + }
>>
>> pr_debug("PM: Preparing processes for restore.\n");
>> error = freeze_processes();
>> @@ -855,7 +859,7 @@ static int software_resume(void)
>> unlock_device_hotplug();
>> thaw_processes();
>> Finish:
>> - pm_notifier_call_chain(PM_POST_RESTORE);
>> + __pm_notifier_call_chain(PM_POST_RESTORE, nr_calls, NULL);
>> pm_restore_console();
>> atomic_inc(&snapshot_device_available);
>> /* For success case, the suspend path will release the lock */
>> diff --git a/kernel/power/main.c b/kernel/power/main.c
>> index 27946975eff0..577a5dec5b35 100644
>> --- a/kernel/power/main.c
>> +++ b/kernel/power/main.c
>> @@ -38,12 +38,19 @@ int unregister_pm_notifier(struct notifier_block *nb)
>> }
>> EXPORT_SYMBOL_GPL(unregister_pm_notifier);
>>
>> -int pm_notifier_call_chain(unsigned long val)
>> +int __pm_notifier_call_chain(unsigned long val, int nr_to_call, int *nr_calls)
>> {
>> - int ret = blocking_notifier_call_chain(&pm_chain_head, val, NULL);
>> + int ret;
>> +
>> + ret = __blocking_notifier_call_chain(&pm_chain_head, val, NULL,
>> + nr_to_call, nr_calls);
>>
>> return notifier_to_errno(ret);
>> }
>> +int pm_notifier_call_chain(unsigned long val)
>> +{
>> + return __pm_notifier_call_chain(val, -1, NULL);
>> +}
>>
>> /* If set, devices may be suspended and resumed asynchronously. */
>> int pm_async_enabled = 1;
>> diff --git a/kernel/power/power.h b/kernel/power/power.h
>> index efe1b3b17c88..51f02ecaf125 100644
>> --- a/kernel/power/power.h
>> +++ b/kernel/power/power.h
>> @@ -200,6 +200,8 @@ static inline void suspend_test_finish(const char *label) {}
>>
>> #ifdef CONFIG_PM_SLEEP
>> /* kernel/power/main.c */
>> +extern int __pm_notifier_call_chain(unsigned long val, int nr_to_call,
>> + int *nr_calls);
>> extern int pm_notifier_call_chain(unsigned long val);
>> #endif
>>
>> diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
>> index 5b70d64b871e..0acab9d7f96f 100644
>> --- a/kernel/power/suspend.c
>> +++ b/kernel/power/suspend.c
>> @@ -266,16 +266,18 @@ static int suspend_test(int level)
>> */
>> static int suspend_prepare(suspend_state_t state)
>> {
>> - int error;
>> + int error, nr_calls = 0;
>>
>> if (!sleep_state_supported(state))
>> return -EPERM;
>>
>> pm_prepare_console();
>>
>> - error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
>> - if (error)
>> + error = __pm_notifier_call_chain(PM_SUSPEND_PREPARE, -1, &nr_calls);
>> + if (error) {
>> + nr_calls--;
>> goto Finish;
>> + }
>>
>> trace_suspend_resume(TPS("freeze_processes"), 0, true);
>> error = suspend_freeze_processes();
>> @@ -286,7 +288,7 @@ static int suspend_prepare(suspend_state_t state)
>> suspend_stats.failed_freeze++;
>> dpm_save_failed_step(SUSPEND_FREEZE);
>> Finish:
>> - pm_notifier_call_chain(PM_POST_SUSPEND);
>> + __pm_notifier_call_chain(PM_POST_SUSPEND, nr_calls, NULL);
>> pm_restore_console();
>> return error;
>> }
>> diff --git a/kernel/power/user.c b/kernel/power/user.c
>> index 526e8911460a..14ad11dd7eb7 100644
>> --- a/kernel/power/user.c
>> +++ b/kernel/power/user.c
>> @@ -47,7 +47,7 @@ atomic_t snapshot_device_available = ATOMIC_INIT(1);
>> static int snapshot_open(struct inode *inode, struct file *filp)
>> {
>> struct snapshot_data *data;
>> - int error;
>> + int error, nr_calls = 0;
>>
>> if (!hibernation_available())
>> return -EPERM;
>> @@ -74,9 +74,11 @@ static int snapshot_open(struct inode *inode, struct file *filp)
>> swap_type_of(swsusp_resume_device, 0, NULL) : -1;
>> data->mode = O_RDONLY;
>> data->free_bitmaps = false;
>> - error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
>> + error = __pm_notifier_call_chain(PM_HIBERNATION_PREPARE,
>> + -1, &nr_calls);
>> if (error)
>> - pm_notifier_call_chain(PM_POST_HIBERNATION);
>> + __pm_notifier_call_chain(PM_POST_HIBERNATION,
>> + --nr_calls, NULL);
>
> I wouldn't break these lines, it looks weird.
Ok, I will put them on the same line.
>
>> } else {
>> /*
>> * Resuming. We may need to wait for the image device to
>> @@ -86,13 +88,17 @@ static int snapshot_open(struct inode *inode, struct file *filp)
>>
>> data->swap = -1;
>> data->mode = O_WRONLY;
>> - error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
>> + error = __pm_notifier_call_chain(PM_RESTORE_PREPARE,
>> + -1, &nr_calls);
>> if (!error) {
>> error = create_basic_memory_bitmaps();
>> data->free_bitmaps = !error;
>> - }
>> + } else
>> + nr_calls--;
>> +
>> if (error)
>> - pm_notifier_call_chain(PM_POST_RESTORE);
>> + __pm_notifier_call_chain(PM_POST_RESTORE,
>> + nr_calls, NULL);
>> }
>> if (error)
>> atomic_inc(&snapshot_device_available);
>>
>
> Thanks,
> Rafael
>
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