| Message ID | 1570927586-12023-1-git-send-email-zhenzhong.duan@oracle.com (mailing list archive) |
|---|---|
| State | Changes Requested, archived |
| Headers | show |
| Series | cpuidle: not unset the driver if it already exist | expand |
On Mon, Oct 14, 2019 at 2:43 AM Zhenzhong Duan <zhenzhong.duan@oracle.com> wrote: > > __cpuidle_set_driver() check if there is an already exist driver and > unset it before return with -EBUSY. The next call will succeed as it's > just unset. This is strange as we should either keep old driver and > return -EBUSY or unset and set new driver and return 0. > > Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com> > --- > drivers/cpuidle/driver.c | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/drivers/cpuidle/driver.c b/drivers/cpuidle/driver.c > index 80c1a83..a200304 100644 > --- a/drivers/cpuidle/driver.c > +++ b/drivers/cpuidle/driver.c > @@ -74,7 +74,6 @@ static inline int __cpuidle_set_driver(struct cpuidle_driver *drv) > for_each_cpu(cpu, drv->cpumask) { > > if (__cpuidle_get_cpu_driver(cpu)) { > - __cpuidle_unset_driver(drv); > return -EBUSY; > } There is a bug here, but it needs to be fixed differently. The function should check if any of the CPUs in the mask have a driver (which is different from drv) already and if so return -EBUSY before updating any cpuidle_drivers per-CPU pointers.
diff --git a/drivers/cpuidle/driver.c b/drivers/cpuidle/driver.c index 80c1a83..a200304 100644 --- a/drivers/cpuidle/driver.c +++ b/drivers/cpuidle/driver.c @@ -74,7 +74,6 @@ static inline int __cpuidle_set_driver(struct cpuidle_driver *drv) for_each_cpu(cpu, drv->cpumask) { if (__cpuidle_get_cpu_driver(cpu)) { - __cpuidle_unset_driver(drv); return -EBUSY; }
__cpuidle_set_driver() check if there is an already exist driver and unset it before return with -EBUSY. The next call will succeed as it's just unset. This is strange as we should either keep old driver and return -EBUSY or unset and set new driver and return 0. Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com> --- drivers/cpuidle/driver.c | 1 - 1 file changed, 1 deletion(-)