On 02/19/2014 06:49 AM, Tejun Heo wrote:
Hello,
On Mon, Feb 17, 2014 at 06:19:00PM +0100, Oleg Nesterov wrote:
acpi_processor_set_throttling() plays with set_cpus_allowed_ptr(current),
this is obviously wrong, and the worker is bound.
Umm... yeah, anything running on workqueues shouldn't be diddling with
cpu affinity. The function even has /* FIXME: use work_on_cpu() */ in
it. I suppose it's about time to actually implement that?
Thanks.
Hi Jiri:
Could you try this patch which reworks ACPI processor throttling with
work_on_cpu()?
diff --git a/drivers/acpi/processor_throttling.c
b/drivers/acpi/processor_throttling.c
index 28baa05..9122d64 100644
--- a/drivers/acpi/processor_throttling.c
+++ b/drivers/acpi/processor_throttling.c
@@ -1060,6 +1060,23 @@ static int
acpi_processor_set_throttling_ptc(struct acpi_processor *pr,
return 0;
}
+struct acpi_processor_throttling_arg {
+ struct acpi_processor *pr;
+ int target_state;
+ bool force;
+};
+
+static long acpi_processor_throttling_fn(void *data)
+{
+ struct acpi_processor_throttling_arg *arg = data;
+ struct acpi_processor *pr = arg->pr;
+ struct acpi_processor_throttling *p_throttling = &pr->throttling;
+
+ return p_throttling->acpi_processor_set_throttling(pr,
+ arg->target_state, arg->force);
+}
+
+
int acpi_processor_set_throttling(struct acpi_processor *pr,
int state, bool force)
{
@@ -1068,7 +1085,8 @@ int acpi_processor_set_throttling(struct
acpi_processor *pr,
unsigned int i;
struct acpi_processor *match_pr;
struct acpi_processor_throttling *p_throttling;
- struct throttling_tstate t_state;
+ struct acpi_processor_throttling_arg arg;
+ struct throttling_tstate t_state;
cpumask_var_t online_throttling_cpus;
if (!pr)
@@ -1083,10 +1101,8 @@ int acpi_processor_set_throttling(struct
acpi_processor *pr,
if (!alloc_cpumask_var(&saved_mask, GFP_KERNEL))
return -ENOMEM;
- if (!alloc_cpumask_var(&online_throttling_cpus, GFP_KERNEL)) {
- free_cpumask_var(saved_mask);
+ if (!alloc_cpumask_var(&online_throttling_cpus, GFP_KERNEL))
return -ENOMEM;
- }
if (cpu_is_offline(pr->id)) {
/*
@@ -1096,7 +1112,6 @@ int acpi_processor_set_throttling(struct
acpi_processor *pr,
return -ENODEV;
}
- cpumask_copy(saved_mask, ¤t->cpus_allowed);
t_state.target_state = state;
p_throttling = &(pr->throttling);
cpumask_and(online_throttling_cpus, cpu_online_mask,
@@ -1118,14 +1133,10 @@ int acpi_processor_set_throttling(struct
acpi_processor *pr,
* it can be called only for the cpu pointed by pr.
*/
if (p_throttling->shared_type == DOMAIN_COORD_TYPE_SW_ANY) {
- /* FIXME: use work_on_cpu() */
- 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);
+ arg.pr = pr;
+ arg.target_state = state;
+ arg.force = force;
+ ret = work_on_cpu(pr->id, acpi_processor_throttling_fn, &arg);
} else {
/*
* When the T-state coordination is SW_ALL or HW_ALL,
@@ -1153,13 +1164,11 @@ int acpi_processor_set_throttling(struct
acpi_processor *pr,
"on CPU %d\n", i));
continue;
}
- t_state.cpu = i;
- /* FIXME: use work_on_cpu() */
- 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);
+
+ arg.pr = match_pr;
+ arg.target_state = state;
+ arg.force = force;
+ ret = work_on_cpu(pr->id, acpi_processor_throttling_fn, &arg);
}
}
/*
@@ -1173,12 +1182,8 @@ int acpi_processor_set_throttling(struct
acpi_processor *pr,
acpi_processor_throttling_notifier(THROTTLING_POSTCHANGE,
&t_state);
}
- /* 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;
}
--
Best Regards
Tianyu Lan
diff --git a/drivers/acpi/processor_throttling.c b/drivers/acpi/processor_throttling.c
index 28baa05..9122d64 100644
--- a/drivers/acpi/processor_throttling.c
+++ b/drivers/acpi/processor_throttling.c
@@ -1060,6 +1060,23 @@ static int acpi_processor_set_throttling_ptc(struct acpi_processor *pr,
return 0;
}
+struct acpi_processor_throttling_arg {
+ struct acpi_processor *pr;
+ int target_state;
+ bool force;
+};
+
+static long acpi_processor_throttling_fn(void *data)
+{
+ struct acpi_processor_throttling_arg *arg = data;
+ struct acpi_processor *pr = arg->pr;
+ struct acpi_processor_throttling *p_throttling = &pr->throttling;
+
+ return p_throttling->acpi_processor_set_throttling(pr,
+ arg->target_state, arg->force);
+}
+
+
int acpi_processor_set_throttling(struct acpi_processor *pr,
int state, bool force)
{
@@ -1068,7 +1085,8 @@ int acpi_processor_set_throttling(struct acpi_processor *pr,
unsigned int i;
struct acpi_processor *match_pr;
struct acpi_processor_throttling *p_throttling;
- struct throttling_tstate t_state;
+ struct acpi_processor_throttling_arg arg;
+ struct throttling_tstate t_state;
cpumask_var_t online_throttling_cpus;
if (!pr)
@@ -1083,10 +1101,8 @@ int acpi_processor_set_throttling(struct acpi_processor *pr,
if (!alloc_cpumask_var(&saved_mask, GFP_KERNEL))
return -ENOMEM;
- if (!alloc_cpumask_var(&online_throttling_cpus, GFP_KERNEL)) {
- free_cpumask_var(saved_mask);
+ if (!alloc_cpumask_var(&online_throttling_cpus, GFP_KERNEL))
return -ENOMEM;
- }
if (cpu_is_offline(pr->id)) {
/*
@@ -1096,7 +1112,6 @@ int acpi_processor_set_throttling(struct acpi_processor *pr,
return -ENODEV;
}
- cpumask_copy(saved_mask, ¤t->cpus_allowed);
t_state.target_state = state;
p_throttling = &(pr->throttling);
cpumask_and(online_throttling_cpus, cpu_online_mask,
@@ -1118,14 +1133,10 @@ int acpi_processor_set_throttling(struct acpi_processor *pr,
* it can be called only for the cpu pointed by pr.
*/
if (p_throttling->shared_type == DOMAIN_COORD_TYPE_SW_ANY) {
- /* FIXME: use work_on_cpu() */
- 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);
+ arg.pr = pr;
+ arg.target_state = state;
+ arg.force = force;
+ ret = work_on_cpu(pr->id, acpi_processor_throttling_fn, &arg);
} else {
/*
* When the T-state coordination is SW_ALL or HW_ALL,
@@ -1153,13 +1164,11 @@ int acpi_processor_set_throttling(struct acpi_processor *pr,
"on CPU %d\n", i));
continue;
}
- t_state.cpu = i;
- /* FIXME: use work_on_cpu() */
- 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);
+
+ arg.pr = match_pr;
+ arg.target_state = state;
+ arg.force = force;
+ ret = work_on_cpu(pr->id, acpi_processor_throttling_fn, &arg);
}
}
/*
@@ -1173,12 +1182,8 @@ int acpi_processor_set_throttling(struct acpi_processor *pr,
acpi_processor_throttling_notifier(THROTTLING_POSTCHANGE,
&t_state);
}
- /* 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;
}
