[PATCH 2/2] rt/threadirqs: remove pointless irq disabling on irq thread handlers

From: Frederic Weisbecker
Date: Thu Feb 12 2009 - 18:18:21 EST


The handlers called by the irq thread lock the desc->lock by
using spin_lock_irq.
But at this stage, the irqs are already disabled at the end
of both handle_IRQ_event() processing and cond_resched_hardirq_context().

A single spin_lock is sufficient.

Signed-off-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
---
kernel/irq/manage.c | 8 +++-----
1 files changed, 3 insertions(+), 5 deletions(-)

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 6e9baf8..8e963a9 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -802,7 +802,7 @@ static void thread_simple_irq(irq_desc_t *desc)
spin_unlock(&desc->lock);
action_ret = handle_IRQ_event(irq, action);
cond_resched_hardirq_context();
- spin_lock_irq(&desc->lock);
+ spin_lock(&desc->lock);
if (!noirqdebug)
note_interrupt(irq, desc, action_ret);
} while (desc->status & IRQ_PENDING);
@@ -863,7 +863,7 @@ static void thread_edge_irq(irq_desc_t *desc)
spin_unlock(&desc->lock);
action_ret = handle_IRQ_event(irq, action);
cond_resched_hardirq_context();
- spin_lock_irq(&desc->lock);
+ spin_lock(&desc->lock);
if (!noirqdebug)
note_interrupt(irq, desc, action_ret);
} while ((desc->status & IRQ_PENDING) && !desc->depth);
@@ -892,7 +892,7 @@ static void thread_do_irq(irq_desc_t *desc)
spin_unlock(&desc->lock);
action_ret = handle_IRQ_event(irq, action);
cond_resched_hardirq_context();
- spin_lock_irq(&desc->lock);
+ spin_lock(&desc->lock);
if (!noirqdebug)
note_interrupt(irq, desc, action_ret);
} while ((desc->status & IRQ_PENDING) && !desc->depth);
@@ -903,8 +903,6 @@ static void thread_do_irq(irq_desc_t *desc)

static void do_hardirq(struct irq_desc *desc)
{
- unsigned long flags;
-
spin_lock(&desc->lock);

if (!(desc->status & IRQ_INPROGRESS))
--
1.6.1


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