| Message ID | 1311760070-21532-4-git-send-email-sven@narfation.org (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
On Wednesday, July 27, 2011, Sven Eckelmann wrote: > atomic_dec_not_zero is defined for each architecture through > <linux/atomic.h> to provide the functionality of > atomic_add_unless(x, -1, 0). > > Signed-off-by: Sven Eckelmann <sven@narfation.org> > Cc: Len Brown <len.brown@intel.com> > Cc: Pavel Machek <pavel@ucw.cz> > Cc: Rafael J. Wysocki <rjw@sisk.pl> > Cc: linux-pm@lists.linux-foundation.org Acked-by: Rafael J. Wysocki <rjw@sisk.pl> > --- > drivers/base/power/runtime.c | 4 ++-- > include/linux/pm_runtime.h | 2 +- > kernel/power/hibernate.c | 4 ++-- > kernel/power/user.c | 2 +- > 4 files changed, 6 insertions(+), 6 deletions(-) > > diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c > index 8dc247c..bda10d9 100644 > --- a/drivers/base/power/runtime.c > +++ b/drivers/base/power/runtime.c > @@ -401,7 +401,7 @@ static int rpm_suspend(struct device *dev, int rpmflags) > > if (dev->parent) { > parent = dev->parent; > - atomic_add_unless(&parent->power.child_count, -1, 0); > + atomic_dec_not_zero(&parent->power.child_count); > } > } > wake_up_all(&dev->power.wait_queue); > @@ -841,7 +841,7 @@ int __pm_runtime_set_status(struct device *dev, unsigned int status) > if (status == RPM_SUSPENDED) { > /* It always is possible to set the status to 'suspended'. */ > if (parent) { > - atomic_add_unless(&parent->power.child_count, -1, 0); > + atomic_dec_not_zero(&parent->power.child_count); > notify_parent = !parent->power.ignore_children; > } > goto out_set; > diff --git a/include/linux/pm_runtime.h b/include/linux/pm_runtime.h > index daac05d..3b4931c 100644 > --- a/include/linux/pm_runtime.h > +++ b/include/linux/pm_runtime.h > @@ -63,7 +63,7 @@ static inline void pm_runtime_get_noresume(struct device *dev) > > static inline void pm_runtime_put_noidle(struct device *dev) > { > - atomic_add_unless(&dev->power.usage_count, -1, 0); > + atomic_dec_not_zero(&dev->power.usage_count); > } > > static inline bool device_run_wake(struct device *dev) > diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c > index 8f7b1db..0ba8d87 100644 > --- a/kernel/power/hibernate.c > +++ b/kernel/power/hibernate.c > @@ -606,7 +606,7 @@ int hibernate(void) > > mutex_lock(&pm_mutex); > /* The snapshot device should not be opened while we're running */ > - if (!atomic_add_unless(&snapshot_device_available, -1, 0)) { > + if (!atomic_dec_not_zero(&snapshot_device_available)) { > error = -EBUSY; > goto Unlock; > } > @@ -756,7 +756,7 @@ static int software_resume(void) > goto Unlock; > > /* The snapshot device should not be opened while we're running */ > - if (!atomic_add_unless(&snapshot_device_available, -1, 0)) { > + if (!atomic_dec_not_zero(&snapshot_device_available)) { > error = -EBUSY; > swsusp_close(FMODE_READ); > goto Unlock; > diff --git a/kernel/power/user.c b/kernel/power/user.c > index 42ddbc6..1c1cc01 100644 > --- a/kernel/power/user.c > +++ b/kernel/power/user.c > @@ -72,7 +72,7 @@ static int snapshot_open(struct inode *inode, struct file *filp) > > mutex_lock(&pm_mutex); > > - if (!atomic_add_unless(&snapshot_device_available, -1, 0)) { > + if (!atomic_dec_not_zero(&snapshot_device_available)) { > error = -EBUSY; > goto Unlock; > } >
Hi! > > atomic_dec_not_zero is defined for each architecture through > > <linux/atomic.h> to provide the functionality of > > atomic_add_unless(x, -1, 0). > > > > Signed-off-by: Sven Eckelmann <sven@narfation.org> > > Cc: Len Brown <len.brown@intel.com> > > Cc: Pavel Machek <pavel@ucw.cz> > > Cc: Rafael J. Wysocki <rjw@sisk.pl> > > Cc: linux-pm@lists.linux-foundation.org > > Acked-by: Rafael J. Wysocki <rjw@sisk.pl> > > > --- > > drivers/base/power/runtime.c | 4 ++-- > > include/linux/pm_runtime.h | 2 +- > > kernel/power/hibernate.c | 4 ++-- > > kernel/power/user.c | 2 +- > > 4 files changed, 6 insertions(+), 6 deletions(-) > > > > diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c > > index 8dc247c..bda10d9 100644 > > --- a/drivers/base/power/runtime.c > > +++ b/drivers/base/power/runtime.c > > @@ -401,7 +401,7 @@ static int rpm_suspend(struct device *dev, int rpmflags) > > > > if (dev->parent) { > > parent = dev->parent; > > - atomic_add_unless(&parent->power.child_count, -1, 0); > > + atomic_dec_not_zero(&parent->power.child_count); I'd like to understand... Why not atomic_dec in the first place? Count should be exact, anyway, or we run into problems, right?
On Wednesday, July 27, 2011, Pavel Machek wrote: > Hi! > > > > atomic_dec_not_zero is defined for each architecture through > > > <linux/atomic.h> to provide the functionality of > > > atomic_add_unless(x, -1, 0). > > > > > > Signed-off-by: Sven Eckelmann <sven@narfation.org> > > > Cc: Len Brown <len.brown@intel.com> > > > Cc: Pavel Machek <pavel@ucw.cz> > > > Cc: Rafael J. Wysocki <rjw@sisk.pl> > > > Cc: linux-pm@lists.linux-foundation.org > > > > Acked-by: Rafael J. Wysocki <rjw@sisk.pl> > > > > > --- > > > drivers/base/power/runtime.c | 4 ++-- > > > include/linux/pm_runtime.h | 2 +- > > > kernel/power/hibernate.c | 4 ++-- > > > kernel/power/user.c | 2 +- > > > 4 files changed, 6 insertions(+), 6 deletions(-) > > > > > > diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c > > > index 8dc247c..bda10d9 100644 > > > --- a/drivers/base/power/runtime.c > > > +++ b/drivers/base/power/runtime.c > > > @@ -401,7 +401,7 @@ static int rpm_suspend(struct device *dev, int rpmflags) > > > > > > if (dev->parent) { > > > parent = dev->parent; > > > - atomic_add_unless(&parent->power.child_count, -1, 0); > > > + atomic_dec_not_zero(&parent->power.child_count); > > I'd like to understand... Why not atomic_dec in the first place? Count > should be exact, anyway, or we run into problems, right? Well, we'll also run into trouble if the count becomes negative. We might throw a WARN_ON() there if the old value weren't as expected, but that would be a separate patch. Thanks, Rafael
diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c index 8dc247c..bda10d9 100644 --- a/drivers/base/power/runtime.c +++ b/drivers/base/power/runtime.c @@ -401,7 +401,7 @@ static int rpm_suspend(struct device *dev, int rpmflags) if (dev->parent) { parent = dev->parent; - atomic_add_unless(&parent->power.child_count, -1, 0); + atomic_dec_not_zero(&parent->power.child_count); } } wake_up_all(&dev->power.wait_queue); @@ -841,7 +841,7 @@ int __pm_runtime_set_status(struct device *dev, unsigned int status) if (status == RPM_SUSPENDED) { /* It always is possible to set the status to 'suspended'. */ if (parent) { - atomic_add_unless(&parent->power.child_count, -1, 0); + atomic_dec_not_zero(&parent->power.child_count); notify_parent = !parent->power.ignore_children; } goto out_set; diff --git a/include/linux/pm_runtime.h b/include/linux/pm_runtime.h index daac05d..3b4931c 100644 --- a/include/linux/pm_runtime.h +++ b/include/linux/pm_runtime.h @@ -63,7 +63,7 @@ static inline void pm_runtime_get_noresume(struct device *dev) static inline void pm_runtime_put_noidle(struct device *dev) { - atomic_add_unless(&dev->power.usage_count, -1, 0); + atomic_dec_not_zero(&dev->power.usage_count); } static inline bool device_run_wake(struct device *dev) diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index 8f7b1db..0ba8d87 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -606,7 +606,7 @@ int hibernate(void) mutex_lock(&pm_mutex); /* The snapshot device should not be opened while we're running */ - if (!atomic_add_unless(&snapshot_device_available, -1, 0)) { + if (!atomic_dec_not_zero(&snapshot_device_available)) { error = -EBUSY; goto Unlock; } @@ -756,7 +756,7 @@ static int software_resume(void) goto Unlock; /* The snapshot device should not be opened while we're running */ - if (!atomic_add_unless(&snapshot_device_available, -1, 0)) { + if (!atomic_dec_not_zero(&snapshot_device_available)) { error = -EBUSY; swsusp_close(FMODE_READ); goto Unlock; diff --git a/kernel/power/user.c b/kernel/power/user.c index 42ddbc6..1c1cc01 100644 --- a/kernel/power/user.c +++ b/kernel/power/user.c @@ -72,7 +72,7 @@ static int snapshot_open(struct inode *inode, struct file *filp) mutex_lock(&pm_mutex); - if (!atomic_add_unless(&snapshot_device_available, -1, 0)) { + if (!atomic_dec_not_zero(&snapshot_device_available)) { error = -EBUSY; goto Unlock; }
atomic_dec_not_zero is defined for each architecture through <linux/atomic.h> to provide the functionality of atomic_add_unless(x, -1, 0). Signed-off-by: Sven Eckelmann <sven@narfation.org> Cc: Len Brown <len.brown@intel.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: linux-pm@lists.linux-foundation.org --- drivers/base/power/runtime.c | 4 ++-- include/linux/pm_runtime.h | 2 +- kernel/power/hibernate.c | 4 ++-- kernel/power/user.c | 2 +- 4 files changed, 6 insertions(+), 6 deletions(-)