diff options
| author | Zhao Yakui <yakui.zhao@intel.com> | 2011-01-10 09:35:44 +0100 |
|---|---|---|
| committer | Len Brown <len.brown@intel.com> | 2011-01-10 18:35:04 +0100 |
| commit | daef1f35ea1e2cca125eecd5f078f40b55eb9105 (patch) | |
| tree | ba3cfad2743cbd70a6d36dfe645c427a1634eeb1 /drivers/acpi | |
| parent | Linux 2.6.37 (diff) | |
| download | linux-daef1f35ea1e2cca125eecd5f078f40b55eb9105.tar.xz linux-daef1f35ea1e2cca125eecd5f078f40b55eb9105.zip | |
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')
| -rw-r--r-- | drivers/acpi/processor_throttling.c | 24 |
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, ¤t->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, ¤t->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; |