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From: arm-kernel@ml•breakpoint.cc (Sebastian Andrzej Siewior)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 2/2 v2] arm: Allow forced irq threading
Date: Mon, 12 Aug 2013 22:03:01 +0200	[thread overview]
Message-ID: <20130812200301.GB4181@breakpoint.cc> (raw)
In-Reply-To: <alpine.LFD.2.02.1302142256520.22263@ionos>

From: Thomas Gleixner <tglx@linutronix•de>

All timer interrupts and the perf interrupt are marked NO_THREAD, so
its safe to allow forced interrupt threading.

Signed-off-by: Thomas Gleixner <tglx@linutronix•de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix•de>
---
On Thu, Feb 14, 2013 at 11:04:48PM +0100, Thomas Gleixner wrote:
> On Thu, 14 Feb 2013, Russell King - ARM Linux wrote:
> 
> > What effect does this have on IRQ latency, particularly on the slower CPUs?
> 
> It does not affect anything unless you add "threadirqs" to the kernel
> command line. This command line argument puts the kernel into forced
> irq threading mode. Otherwise it just works as now.

I reposted the patch since it no longer applies clean on v3.11-rc5. From what
tglx explained, I don't think there are any outstanding issues, are there?

 arch/arm/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 43594d5..405e4c0 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -20,6 +20,7 @@ config ARM
 	select GENERIC_STRNCPY_FROM_USER
 	select GENERIC_STRNLEN_USER
 	select HARDIRQS_SW_RESEND
+	select IRQ_FORCED_THREADING
 	select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL
 	select HAVE_ARCH_KGDB
 	select HAVE_ARCH_SECCOMP_FILTER
-- 
1.8.4.rc1

  reply	other threads:[~2013-08-12 20:03 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-02-14 20:53 [patch 0/2] ARM: Allow forced irq threading Thomas Gleixner
2013-02-14 20:53 ` [patch 1/2] arm: Mark pmu interupt IRQF_NO_THREAD Thomas Gleixner
2013-02-15  9:51   ` Will Deacon
2013-08-12 19:52     ` Sebastian Andrzej Siewior
2013-08-13 11:11       ` Will Deacon
2013-08-14  9:52         ` Sebastian Andrzej Siewior
2013-02-14 20:53 ` [patch 2/2] arm: Allow forced irq threading Thomas Gleixner
2013-02-14 21:49   ` Russell King - ARM Linux
2013-02-14 22:04     ` Thomas Gleixner
2013-08-12 20:03       ` Sebastian Andrzej Siewior [this message]
2013-08-14 10:08         ` [PATCH 2/2 v2] " Sekhar Nori
2013-08-14 14:43           ` [PATCH 2/2 v3] " Sebastian Andrzej Siewior

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