* [PATCH 1/2] rt/threadirqs: don't need to save irqs in do_hardirq()
@ 2009-02-12 18:27 Frederic Weisbecker
2009-02-12 23:24 ` Arnaldo Carvalho de Melo
0 siblings, 1 reply; 5+ messages in thread
From: Frederic Weisbecker @ 2009-02-12 18:27 UTC (permalink / raw)
To: Steven Rostedt; +Cc: linux-kernel
do_hardirq() has only one caller do_irqd() in a path where irq are already
disabled. So we don't need to save irqs while holding desc->lock
Replace spin_lock_irqsave by spin_lock.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
---
kernel/irq/manage.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index ed7c5e3..6e9baf8 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -905,7 +905,7 @@ static void do_hardirq(struct irq_desc *desc)
{
unsigned long flags;
- spin_lock_irqsave(&desc->lock, flags);
+ spin_lock(&desc->lock);
if (!(desc->status & IRQ_INPROGRESS))
goto out;
@@ -921,7 +921,7 @@ static void do_hardirq(struct irq_desc *desc)
else
thread_do_irq(desc);
out:
- spin_unlock_irqrestore(&desc->lock, flags);
+ spin_unlock(&desc->lock);
if (waitqueue_active(&desc->wait_for_handler))
wake_up(&desc->wait_for_handler);
--
1.6.1
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH 1/2] rt/threadirqs: don't need to save irqs in do_hardirq()
2009-02-12 18:27 [PATCH 1/2] rt/threadirqs: don't need to save irqs in do_hardirq() Frederic Weisbecker
@ 2009-02-12 23:24 ` Arnaldo Carvalho de Melo
2009-02-12 23:27 ` Frederic Weisbecker
0 siblings, 1 reply; 5+ messages in thread
From: Arnaldo Carvalho de Melo @ 2009-02-12 23:24 UTC (permalink / raw)
To: Frederic Weisbecker; +Cc: Steven Rostedt, linux-kernel
Em Thu, Feb 12, 2009 at 07:27:08PM +0100, Frederic Weisbecker escreveu:
> do_hardirq() has only one caller do_irqd() in a path where irq are already
> disabled. So we don't need to save irqs while holding desc->lock
>
> Replace spin_lock_irqsave by spin_lock.
>
> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
> ---
> kernel/irq/manage.c | 4 ++--
> 1 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
> index ed7c5e3..6e9baf8 100644
> --- a/kernel/irq/manage.c
> +++ b/kernel/irq/manage.c
> @@ -905,7 +905,7 @@ static void do_hardirq(struct irq_desc *desc)
> {
> unsigned long flags;
Can flags be removed too?
> - spin_lock_irqsave(&desc->lock, flags);
> + spin_lock(&desc->lock);
>
> if (!(desc->status & IRQ_INPROGRESS))
> goto out;
> @@ -921,7 +921,7 @@ static void do_hardirq(struct irq_desc *desc)
> else
> thread_do_irq(desc);
> out:
> - spin_unlock_irqrestore(&desc->lock, flags);
> + spin_unlock(&desc->lock);
>
> if (waitqueue_active(&desc->wait_for_handler))
> wake_up(&desc->wait_for_handler);
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH 1/2] rt/threadirqs: don't need to save irqs in do_hardirq()
2009-02-12 23:24 ` Arnaldo Carvalho de Melo
@ 2009-02-12 23:27 ` Frederic Weisbecker
2009-02-12 23:37 ` Steven Rostedt
0 siblings, 1 reply; 5+ messages in thread
From: Frederic Weisbecker @ 2009-02-12 23:27 UTC (permalink / raw)
To: Arnaldo Carvalho de Melo; +Cc: Steven Rostedt, linux-kernel
On Thu, Feb 12, 2009 at 09:24:59PM -0200, Arnaldo Carvalho de Melo wrote:
> Em Thu, Feb 12, 2009 at 07:27:08PM +0100, Frederic Weisbecker escreveu:
> > do_hardirq() has only one caller do_irqd() in a path where irq are already
> > disabled. So we don't need to save irqs while holding desc->lock
> >
> > Replace spin_lock_irqsave by spin_lock.
> >
> > Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
> > ---
> > kernel/irq/manage.c | 4 ++--
> > 1 files changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
> > index ed7c5e3..6e9baf8 100644
> > --- a/kernel/irq/manage.c
> > +++ b/kernel/irq/manage.c
> > @@ -905,7 +905,7 @@ static void do_hardirq(struct irq_desc *desc)
> > {
> > unsigned long flags;
>
> Can flags be removed too?
Actually... I cheated.
Once the two patches were done, I saw the unused variable warning. So I remade the second patch
to remove flags but..yes it should be on the first patch, I must confess...
> > - spin_lock_irqsave(&desc->lock, flags);
> > + spin_lock(&desc->lock);
> >
> > if (!(desc->status & IRQ_INPROGRESS))
> > goto out;
> > @@ -921,7 +921,7 @@ static void do_hardirq(struct irq_desc *desc)
> > else
> > thread_do_irq(desc);
> > out:
> > - spin_unlock_irqrestore(&desc->lock, flags);
> > + spin_unlock(&desc->lock);
> >
> > if (waitqueue_active(&desc->wait_for_handler))
> > wake_up(&desc->wait_for_handler);
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH 1/2] rt/threadirqs: don't need to save irqs in do_hardirq()
2009-02-12 23:27 ` Frederic Weisbecker
@ 2009-02-12 23:37 ` Steven Rostedt
2009-02-12 23:43 ` Arnaldo Carvalho de Melo
0 siblings, 1 reply; 5+ messages in thread
From: Steven Rostedt @ 2009-02-12 23:37 UTC (permalink / raw)
To: Frederic Weisbecker; +Cc: Arnaldo Carvalho de Melo, linux-kernel
On Fri, 13 Feb 2009, Frederic Weisbecker wrote:
> On Thu, Feb 12, 2009 at 09:24:59PM -0200, Arnaldo Carvalho de Melo wrote:
> > Em Thu, Feb 12, 2009 at 07:27:08PM +0100, Frederic Weisbecker escreveu:
> > > do_hardirq() has only one caller do_irqd() in a path where irq are already
> > > disabled. So we don't need to save irqs while holding desc->lock
> > >
> > > Replace spin_lock_irqsave by spin_lock.
> > >
> > > Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
> > > ---
> > > kernel/irq/manage.c | 4 ++--
> > > 1 files changed, 2 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
> > > index ed7c5e3..6e9baf8 100644
> > > --- a/kernel/irq/manage.c
> > > +++ b/kernel/irq/manage.c
> > > @@ -905,7 +905,7 @@ static void do_hardirq(struct irq_desc *desc)
> > > {
> > > unsigned long flags;
> >
> > Can flags be removed too?
>
>
> Actually... I cheated.
> Once the two patches were done, I saw the unused variable warning. So I remade the second patch
> to remove flags but..yes it should be on the first patch, I must confess...
That's fine, I'll pull both of them in.
Thanks Frederic!
-- Steve
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH 1/2] rt/threadirqs: don't need to save irqs in do_hardirq()
2009-02-12 23:37 ` Steven Rostedt
@ 2009-02-12 23:43 ` Arnaldo Carvalho de Melo
0 siblings, 0 replies; 5+ messages in thread
From: Arnaldo Carvalho de Melo @ 2009-02-12 23:43 UTC (permalink / raw)
To: Steven Rostedt; +Cc: Frederic Weisbecker, linux-kernel
Em Thu, Feb 12, 2009 at 06:37:16PM -0500, Steven Rostedt escreveu:
>
> On Fri, 13 Feb 2009, Frederic Weisbecker wrote:
>
> > On Thu, Feb 12, 2009 at 09:24:59PM -0200, Arnaldo Carvalho de Melo wrote:
> > > Em Thu, Feb 12, 2009 at 07:27:08PM +0100, Frederic Weisbecker escreveu:
> > > > do_hardirq() has only one caller do_irqd() in a path where irq are already
> > > > disabled. So we don't need to save irqs while holding desc->lock
> > > >
> > > > Replace spin_lock_irqsave by spin_lock.
> > > >
> > > > Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
> > > > ---
> > > > kernel/irq/manage.c | 4 ++--
> > > > 1 files changed, 2 insertions(+), 2 deletions(-)
> > > >
> > > > diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
> > > > index ed7c5e3..6e9baf8 100644
> > > > --- a/kernel/irq/manage.c
> > > > +++ b/kernel/irq/manage.c
> > > > @@ -905,7 +905,7 @@ static void do_hardirq(struct irq_desc *desc)
> > > > {
> > > > unsigned long flags;
> > >
> > > Can flags be removed too?
> >
> >
> > Actually... I cheated.
> > Once the two patches were done, I saw the unused variable warning. So I remade the second patch
> > to remove flags but..yes it should be on the first patch, I must confess...
>
> That's fine, I'll pull both of them in.
>
> Thanks Frederic!
Ditto, that was just a follow up thingy, nothing against the change :-)
- Arnaldo
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2009-02-12 23:44 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
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2009-02-12 18:27 [PATCH 1/2] rt/threadirqs: don't need to save irqs in do_hardirq() Frederic Weisbecker
2009-02-12 23:24 ` Arnaldo Carvalho de Melo
2009-02-12 23:27 ` Frederic Weisbecker
2009-02-12 23:37 ` Steven Rostedt
2009-02-12 23:43 ` Arnaldo Carvalho de Melo
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