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authorZhao Yakui <yakui.zhao@intel.com>2011-01-10 16:35:44 +0800
committerLen Brown <len.brown@intel.com>2011-01-10 12:35:04 -0500
commitdaef1f35ea1e2cca125eecd5f078f40b55eb9105 (patch)
treeba3cfad2743cbd70a6d36dfe645c427a1634eeb1 /drivers/acpi/processor_throttling.c
parent3c0eee3fe6a3a1c745379547c7e7c904aa64f6d5 (diff)
ACPI: Check the returned value of set_cpus_allowed_ptr before T-state operation
Now before it executes the T-state operation on one CPU, it will try to migrate to the target CPU. Especially this is required on the system that uses the MSR_IA32_THERMAL_CONTROL register to switch T-state. But unfortunately it doesn't check whether the migration is successful or not. In such case we will get/set the incorrect T-state on the offline CPU as it fails in the migration to the offline CPU. Signed-off-by: Zhao Yakui <yakui.zhao@intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'drivers/acpi/processor_throttling.c')
-rw-r--r--drivers/acpi/processor_throttling.c24
1 files changed, 21 insertions, 3 deletions
diff --git a/drivers/acpi/processor_throttling.c b/drivers/acpi/processor_throttling.c
index ff3632717c51..ffc859c61393 100644
--- a/drivers/acpi/processor_throttling.c
+++ b/drivers/acpi/processor_throttling.c
@@ -876,7 +876,11 @@ static int acpi_processor_get_throttling(struct acpi_processor *pr)
*/
cpumask_copy(saved_mask, &current->cpus_allowed);
/* FIXME: use work_on_cpu() */
- set_cpus_allowed_ptr(current, cpumask_of(pr->id));
+ if (set_cpus_allowed_ptr(current, cpumask_of(pr->id))) {
+ /* Can't migrate to the target pr->id CPU. Exit */
+ free_cpumask_var(saved_mask);
+ return -ENODEV;
+ }
ret = pr->throttling.acpi_processor_get_throttling(pr);
/* restore the previous state */
set_cpus_allowed_ptr(current, saved_mask);
@@ -1051,6 +1055,14 @@ int acpi_processor_set_throttling(struct acpi_processor *pr,
return -ENOMEM;
}
+ if (cpu_is_offline(pr->id)) {
+ /*
+ * the cpu pointed by pr->id is offline. Unnecessary to change
+ * the throttling state any more.
+ */
+ return -ENODEV;
+ }
+
cpumask_copy(saved_mask, &current->cpus_allowed);
t_state.target_state = state;
p_throttling = &(pr->throttling);
@@ -1074,7 +1086,11 @@ int acpi_processor_set_throttling(struct acpi_processor *pr,
*/
if (p_throttling->shared_type == DOMAIN_COORD_TYPE_SW_ANY) {
/* FIXME: use work_on_cpu() */
- set_cpus_allowed_ptr(current, cpumask_of(pr->id));
+ if (set_cpus_allowed_ptr(current, cpumask_of(pr->id))) {
+ /* Can't migrate to the pr->id CPU. Exit */
+ ret = -ENODEV;
+ goto exit;
+ }
ret = p_throttling->acpi_processor_set_throttling(pr,
t_state.target_state, force);
} else {
@@ -1106,7 +1122,8 @@ int acpi_processor_set_throttling(struct acpi_processor *pr,
}
t_state.cpu = i;
/* FIXME: use work_on_cpu() */
- set_cpus_allowed_ptr(current, cpumask_of(i));
+ if (set_cpus_allowed_ptr(current, cpumask_of(i)))
+ continue;
ret = match_pr->throttling.
acpi_processor_set_throttling(
match_pr, t_state.target_state, force);
@@ -1126,6 +1143,7 @@ int acpi_processor_set_throttling(struct acpi_processor *pr,
/* restore the previous state */
/* FIXME: use work_on_cpu() */
set_cpus_allowed_ptr(current, saved_mask);
+exit:
free_cpumask_var(online_throttling_cpus);
free_cpumask_var(saved_mask);
return ret;