[RT git pull] fixes for rt/sched

[RT git pull] fixes for rt/sched

[Gregory Haskins]

The following changes since commit cfe6498c6a03e574bc9384cc95d73dfd20a13f05:
  Steven Rostedt (1):
        rt sched: add rt overload stats

are available in the git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/ghaskins/linux-2.6-hacks.git rt/sched

Gregory Haskins (1):
      rt/sched: ensure interrupts are disabled during post-schedule() processing

 kernel/sched_rt.c |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)

---------------

rt/sched: ensure interrupts are disabled during post-schedule() processing

Impact: Fix run-time opps at boot up.

post-schedule() is required to run with interrupts disabled, but we
currently rely on the caller to have left them disabled for us.  This
has apparently changed recently such that interrupts are now on and
we thus crash.  Fix this once and for all by using the irqsave/restore
variants of spin_lock(rq). 

Signed-off-by: Gregory Haskins <ghaskins@novell.com>
CC: John Stultz <johnstul@us.ibm.com>
---

 kernel/sched_rt.c |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index 856f6fb..0cd6b07 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -1348,14 +1348,16 @@ static int needs_post_schedule_rt(struct rq *rq)
 
 static void post_schedule_rt(struct rq *rq)
 {
+	unsigned long flags;
+
 	/*
 	 * This is only called if needs_post_schedule_rt() indicates that
 	 * we need to push tasks away
 	 */
-	spin_lock(&rq->lock);
+	spin_lock_irqsave(&rq->lock, flags);
 	push_rt_tasks(rq);
 	schedstat_inc(rq, rto_schedule_tail);
-	spin_unlock(&rq->lock);
+	spin_unlock_irqrestore(&rq->lock, flags);
 }
 
 /*

Re: [RT git pull] fixes for rt/sched

[Gregory Haskins]

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[ Forgot to CC John the first time around ]

Gregory Haskins wrote:
> The following changes since commit cfe6498c6a03e574bc9384cc95d73dfd20a13f05:
>   Steven Rostedt (1):
>         rt sched: add rt overload stats
>
> are available in the git repository at:
>
>   git://git.kernel.org/pub/scm/linux/kernel/git/ghaskins/linux-2.6-hacks.git rt/sched
>
> Gregory Haskins (1):
>       rt/sched: ensure interrupts are disabled during post-schedule() processing
>
>  kernel/sched_rt.c |    6 ++++--
>  1 files changed, 4 insertions(+), 2 deletions(-)
>
> ---------------
>
> rt/sched: ensure interrupts are disabled during post-schedule() processing
>
> Impact: Fix run-time opps at boot up.
>
> post-schedule() is required to run with interrupts disabled, but we
> currently rely on the caller to have left them disabled for us.  This
> has apparently changed recently such that interrupts are now on and
> we thus crash.  Fix this once and for all by using the irqsave/restore
> variants of spin_lock(rq). 
>
> Signed-off-by: Gregory Haskins <ghaskins@novell.com>
> CC: John Stultz <johnstul@us.ibm.com>
> ---
>
>  kernel/sched_rt.c |    6 ++++--
>  1 files changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
> index 856f6fb..0cd6b07 100644
> --- a/kernel/sched_rt.c
> +++ b/kernel/sched_rt.c
> @@ -1348,14 +1348,16 @@ static int needs_post_schedule_rt(struct rq *rq)
>  
>  static void post_schedule_rt(struct rq *rq)
>  {
> +	unsigned long flags;
> +
>  	/*
>  	 * This is only called if needs_post_schedule_rt() indicates that
>  	 * we need to push tasks away
>  	 */
> -	spin_lock(&rq->lock);
> +	spin_lock_irqsave(&rq->lock, flags);
>  	push_rt_tasks(rq);
>  	schedstat_inc(rq, rto_schedule_tail);
> -	spin_unlock(&rq->lock);
> +	spin_unlock_irqrestore(&rq->lock, flags);
>  }
>  
>  /*
>
>   



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Re: [RT git pull] fixes for rt/sched

[Steven Rostedt]

On Wed, 14 Jan 2009, Gregory Haskins wrote:

> [ Forgot to CC John the first time around ]
> 
> Gregory Haskins wrote:
> > The following changes since commit cfe6498c6a03e574bc9384cc95d73dfd20a13f05:
> >   Steven Rostedt (1):
> >         rt sched: add rt overload stats
> >
> > are available in the git repository at:
> >
> >   git://git.kernel.org/pub/scm/linux/kernel/git/ghaskins/linux-2.6-hacks.git rt/sched
> >
> > Gregory Haskins (1):
> >       rt/sched: ensure interrupts are disabled during post-schedule() processing
> >
> >  kernel/sched_rt.c |    6 ++++--
> >  1 files changed, 4 insertions(+), 2 deletions(-)
> >


Thanks, applied.

(to git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-rt.git)

-- Steve