* Re: [PATCH] softirq: Avoid stack switch from ksoftirqd
2011-02-02 16:10 [PATCH] softirq: Avoid stack switch from ksoftirqd Thomas Gleixner
@ 2011-02-02 16:24 ` Peter Zijlstra
2011-02-02 21:51 ` David Miller
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: Peter Zijlstra @ 2011-02-02 16:24 UTC (permalink / raw)
To: Thomas Gleixner
Cc: LKML, Ingo Molnar, Benjamin Herrenschmidt, Heiko Carstens,
David Miller, Paul Mundt
On Wed, 2011-02-02 at 17:10 +0100, Thomas Gleixner wrote:
> ksoftirqd() calls do_softirq() which switches stacks on several
> architectures. That makes no sense at all. ksoftirqd's stack is
> sufficient.
>
> Call __do_softirq() directly.
>
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
> ---
> kernel/softirq.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> Index: linux-2.6-tip/kernel/softirq.c
> ===================================================================
> --- linux-2.6-tip.orig/kernel/softirq.c
> +++ linux-2.6-tip/kernel/softirq.c
> @@ -738,7 +738,10 @@ static int run_ksoftirqd(void * __bind_c
> don't process */
> if (cpu_is_offline((long)__bind_cpu))
> goto wait_to_die;
> - do_softirq();
> + local_irq_disable();
> + if (local_softirq_pending())
> + __do_softirq();
> + local_irq_enable();
> preempt_enable_no_resched();
> cond_resched();
> preempt_disable();
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH] softirq: Avoid stack switch from ksoftirqd
2011-02-02 16:10 [PATCH] softirq: Avoid stack switch from ksoftirqd Thomas Gleixner
2011-02-02 16:24 ` Peter Zijlstra
@ 2011-02-02 21:51 ` David Miller
2011-02-02 23:32 ` Frank Rowand
2011-02-08 18:39 ` [tip:irq/core] " tip-bot for Thomas Gleixner
3 siblings, 0 replies; 5+ messages in thread
From: David Miller @ 2011-02-02 21:51 UTC (permalink / raw)
To: tglx; +Cc: linux-kernel, peterz, mingo, benh, heiko.carstens, lethal
From: Thomas Gleixner <tglx@linutronix.de>
Date: Wed, 2 Feb 2011 17:10:48 +0100 (CET)
> ksoftirqd() calls do_softirq() which switches stacks on several
> architectures. That makes no sense at all. ksoftirqd's stack is
> sufficient.
>
> Call __do_softirq() directly.
>
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: David S. Miller <davem@davemloft.net>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] softirq: Avoid stack switch from ksoftirqd
2011-02-02 16:10 [PATCH] softirq: Avoid stack switch from ksoftirqd Thomas Gleixner
2011-02-02 16:24 ` Peter Zijlstra
2011-02-02 21:51 ` David Miller
@ 2011-02-02 23:32 ` Frank Rowand
2011-02-08 18:39 ` [tip:irq/core] " tip-bot for Thomas Gleixner
3 siblings, 0 replies; 5+ messages in thread
From: Frank Rowand @ 2011-02-02 23:32 UTC (permalink / raw)
To: Thomas Gleixner
Cc: LKML, Peter Zijlstra, Ingo Molnar, Benjamin Herrenschmidt,
Heiko Carstens, David Miller, Paul Mundt
On 02/02/11 08:10, Thomas Gleixner wrote:
> ksoftirqd() calls do_softirq() which switches stacks on several
> architectures. That makes no sense at all. ksoftirqd's stack is
> sufficient.
>
> Call __do_softirq() directly.
>
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frank Rowand <frank.rowand@am.sony.com>
> ---
> kernel/softirq.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> Index: linux-2.6-tip/kernel/softirq.c
> ===================================================================
> --- linux-2.6-tip.orig/kernel/softirq.c
> +++ linux-2.6-tip/kernel/softirq.c
> @@ -738,7 +738,10 @@ static int run_ksoftirqd(void * __bind_c
> don't process */
> if (cpu_is_offline((long)__bind_cpu))
> goto wait_to_die;
> - do_softirq();
> + local_irq_disable();
> + if (local_softirq_pending())
> + __do_softirq();
> + local_irq_enable();
> preempt_enable_no_resched();
> cond_resched();
> preempt_disable();
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
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> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* [tip:irq/core] softirq: Avoid stack switch from ksoftirqd
2011-02-02 16:10 [PATCH] softirq: Avoid stack switch from ksoftirqd Thomas Gleixner
` (2 preceding siblings ...)
2011-02-02 23:32 ` Frank Rowand
@ 2011-02-08 18:39 ` tip-bot for Thomas Gleixner
3 siblings, 0 replies; 5+ messages in thread
From: tip-bot for Thomas Gleixner @ 2011-02-08 18:39 UTC (permalink / raw)
To: linux-tip-commits
Cc: linux-kernel, hpa, mingo, peterz, lethal, davem, benh,
heiko.carstens, frank.rowand, tglx
Commit-ID: c305d524e5dd3c3c7a6035083e30950bea1b52dc
Gitweb: http://git.kernel.org/tip/c305d524e5dd3c3c7a6035083e30950bea1b52dc
Author: Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Wed, 2 Feb 2011 17:10:48 +0100
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitDate: Tue, 8 Feb 2011 19:37:12 +0100
softirq: Avoid stack switch from ksoftirqd
ksoftirqd() calls do_softirq() which switches stacks on several
architectures. That makes no sense at all. ksoftirqd's stack is
sufficient.
Call __do_softirq() directly.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: David Miller <davem@davemloft.net>
Cc: Paul Mundt <lethal@linux-sh.org>
Reviewed-by: Frank Rowand <frank.rowand@am.sony.com>
LKML-Reference: <alpine.LFD.2.00.1102021704530.31804@localhost6.localdomain6>
---
kernel/softirq.c | 5 ++++-
1 files changed, 4 insertions(+), 1 deletions(-)
diff --git a/kernel/softirq.c b/kernel/softirq.c
index 68eb5ef..c049046 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -738,7 +738,10 @@ static int run_ksoftirqd(void * __bind_cpu)
don't process */
if (cpu_is_offline((long)__bind_cpu))
goto wait_to_die;
- do_softirq();
+ local_irq_disable();
+ if (local_softirq_pending())
+ __do_softirq();
+ local_irq_enable();
preempt_enable_no_resched();
cond_resched();
preempt_disable();
^ permalink raw reply related [flat|nested] 5+ messages in thread