[tip:irq/core] genirq: Set irq thread to RT priority on creation
Commit-ID: ee23871389d51e07380d23887333622fbe7d3dd9
Gitweb: http://git.kernel.org/tip/ee23871389d51e07380d23887333622fbe7d3dd9
Author: Ivo Sieben
AuthorDate: Mon, 3 Jun 2013 12:12:02 +0200
Committer: Thomas Gleixner
CommitDate: Tue, 11 Jun 2013 16:18:50 +0200
genirq: Set irq thread to RT priority on creation
When a threaded irq handler is installed the irq thread is initially
created on normal scheduling priority. Only after the irq thread is
woken up it sets its priority to RT_FIFO MAX_USER_RT_PRIO/2 itself.
This means that interrupts that occur directly after the irq handler
is installed will be handled on a normal scheduling priority instead
of the realtime priority that one would expect.
Fix this by setting the RT priority on creation of the irq_thread.
Signed-off-by: Ivo Sieben
Cc: Sebastian Andrzej Siewior
Cc: Steven Rostedt
Link:
http://lkml.kernel.org/r/1370254322-17240-1-git-send-email-meltedpiano...@gmail.com
Signed-off-by: Thomas Gleixner
---
kernel/irq/manage.c | 11 ++-
1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index fa17855..e16caa8 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -840,9 +840,6 @@ static void irq_thread_dtor(struct callback_head *unused)
static int irq_thread(void *data)
{
struct callback_head on_exit_work;
- static const struct sched_param param = {
- .sched_priority = MAX_USER_RT_PRIO/2,
- };
struct irqaction *action = data;
struct irq_desc *desc = irq_to_desc(action->irq);
irqreturn_t (*handler_fn)(struct irq_desc *desc,
@@ -854,8 +851,6 @@ static int irq_thread(void *data)
else
handler_fn = irq_thread_fn;
- sched_setscheduler(current, SCHED_FIFO, );
-
init_task_work(_exit_work, irq_thread_dtor);
task_work_add(current, _exit_work, false);
@@ -950,6 +945,9 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct
irqaction *new)
*/
if (new->thread_fn && !nested) {
struct task_struct *t;
+ static const struct sched_param param = {
+ .sched_priority = MAX_USER_RT_PRIO/2,
+ };
t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
new->name);
@@ -957,6 +955,9 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct
irqaction *new)
ret = PTR_ERR(t);
goto out_mput;
}
+
+ sched_setscheduler(t, SCHED_FIFO, );
+
/*
* We keep the reference to the task struct even if
* the thread dies to avoid that the interrupt code
--
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[tip:irq/core] genirq: Set irq thread to RT priority on creation
Commit-ID: ee23871389d51e07380d23887333622fbe7d3dd9
Gitweb: http://git.kernel.org/tip/ee23871389d51e07380d23887333622fbe7d3dd9
Author: Ivo Sieben meltedpiano...@gmail.com
AuthorDate: Mon, 3 Jun 2013 12:12:02 +0200
Committer: Thomas Gleixner t...@linutronix.de
CommitDate: Tue, 11 Jun 2013 16:18:50 +0200
genirq: Set irq thread to RT priority on creation
When a threaded irq handler is installed the irq thread is initially
created on normal scheduling priority. Only after the irq thread is
woken up it sets its priority to RT_FIFO MAX_USER_RT_PRIO/2 itself.
This means that interrupts that occur directly after the irq handler
is installed will be handled on a normal scheduling priority instead
of the realtime priority that one would expect.
Fix this by setting the RT priority on creation of the irq_thread.
Signed-off-by: Ivo Sieben meltedpiano...@gmail.com
Cc: Sebastian Andrzej Siewior bige...@linutronix.de
Cc: Steven Rostedt rost...@goodmis.org
Link:
http://lkml.kernel.org/r/1370254322-17240-1-git-send-email-meltedpiano...@gmail.com
Signed-off-by: Thomas Gleixner t...@linutronix.de
---
kernel/irq/manage.c | 11 ++-
1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index fa17855..e16caa8 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -840,9 +840,6 @@ static void irq_thread_dtor(struct callback_head *unused)
static int irq_thread(void *data)
{
struct callback_head on_exit_work;
- static const struct sched_param param = {
- .sched_priority = MAX_USER_RT_PRIO/2,
- };
struct irqaction *action = data;
struct irq_desc *desc = irq_to_desc(action-irq);
irqreturn_t (*handler_fn)(struct irq_desc *desc,
@@ -854,8 +851,6 @@ static int irq_thread(void *data)
else
handler_fn = irq_thread_fn;
- sched_setscheduler(current, SCHED_FIFO, param);
-
init_task_work(on_exit_work, irq_thread_dtor);
task_work_add(current, on_exit_work, false);
@@ -950,6 +945,9 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct
irqaction *new)
*/
if (new-thread_fn !nested) {
struct task_struct *t;
+ static const struct sched_param param = {
+ .sched_priority = MAX_USER_RT_PRIO/2,
+ };
t = kthread_create(irq_thread, new, irq/%d-%s, irq,
new-name);
@@ -957,6 +955,9 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct
irqaction *new)
ret = PTR_ERR(t);
goto out_mput;
}
+
+ sched_setscheduler(t, SCHED_FIFO, param);
+
/*
* We keep the reference to the task struct even if
* the thread dies to avoid that the interrupt code
--
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