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Subject[PATCH 1/3] genirq: Get rid of unneeded force parameter in irq_finalize_oneshot()
The only place irq_finalize_oneshot() is called with force parameter set
is the threaded handler error exit path. But IRQTF_RUNTHREAD is dropped
at this point and irq_wake_thread() is not going to reset it again,
since PF_EXITING is set for this thread already. So we will drop the
thread's bit in threads_oneshot anyway and the force parameter is
superfluous.

Also, the orded or checking PF_EXITING and IRQTF_RUNTHREAD flags in
irq_wake_thread() is important now, so escalate it more visibly in the
source code.
---
kernel/irq/handle.c | 16 ++++++++++------
kernel/irq/manage.c | 10 +++++-----
2 files changed, 15 insertions(+), 11 deletions(-)
diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index 6ff84e6..bdb1803 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -54,14 +54,18 @@ static void warn_no_thread(unsigned int irq, struct irqaction *action)
static void irq_wake_thread(struct irq_desc *desc, struct irqaction *action)
{
/*
- * Wake up the handler thread for this action. In case the
- * thread crashed and was killed we just pretend that we
- * handled the interrupt. The hardirq handler has disabled the
- * device interrupt, so no irq storm is lurking. If the
+ * In case the thread crashed and was killed we just pretend that
+ * we handled the interrupt. The hardirq handler has disabled the
+ * device interrupt, so no irq storm is lurking.
+ */
+ if (action->thread->flags & PF_EXITING)
+ return;
+
+ /*
+ * Wake up the handler thread for this action. If the
* RUNTHREAD bit is already set, nothing to do.
*/
- if ((action->thread->flags & PF_EXITING) ||
- test_and_set_bit(IRQTF_RUNTHREAD, &action->thread_flags))
+ if (test_and_set_bit(IRQTF_RUNTHREAD, &action->thread_flags))
return;

/*
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index b0ccd1a..bf606a5 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -645,7 +645,7 @@ static int irq_wait_for_interrupt(struct irqaction *action)
* is marked MASKED.
*/
static void irq_finalize_oneshot(struct irq_desc *desc,
- struct irqaction *action, bool force)
+ struct irqaction *action)
{
if (!(desc->istate & IRQS_ONESHOT))
return;
@@ -679,7 +679,7 @@ again:
* we would clear the threads_oneshot bit of this thread which
* was just set.
*/
- if (!force && test_bit(IRQTF_RUNTHREAD, &action->thread_flags))
+ if (test_bit(IRQTF_RUNTHREAD, &action->thread_flags))
goto out_unlock;

desc->threads_oneshot &= ~action->thread_mask;
@@ -739,7 +739,7 @@ irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)

local_bh_disable();
ret = action->thread_fn(action->irq, action->dev_id);
- irq_finalize_oneshot(desc, action, false);
+ irq_finalize_oneshot(desc, action);
local_bh_enable();
return ret;
}
@@ -755,7 +755,7 @@ static irqreturn_t irq_thread_fn(struct irq_desc *desc,
irqreturn_t ret;

ret = action->thread_fn(action->irq, action->dev_id);
- irq_finalize_oneshot(desc, action, false);
+ irq_finalize_oneshot(desc, action);
return ret;
}

@@ -844,7 +844,7 @@ void exit_irq_thread(void)
wake_threads_waitq(desc);

/* Prevent a stale desc->threads_oneshot */
- irq_finalize_oneshot(desc, action, true);
+ irq_finalize_oneshot(desc, action);
}

static void irq_setup_forced_threading(struct irqaction *new)
--
1.7.7.6


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