[PATCH -rt] use SA_NODELAY for XScale PMU interrupts

[PATCH -rt] use SA_NODELAY for XScale PMU interrupts

[Kevin Hilman]

In the XScale oprofile support, the performance monitoring unit (PMU)
triggers interrupts and the ISR reads out the performance data.  These
ISRs are currently set to SA_INTERRUPT.  In order to get accurate
performance and profiling data under PREEMPT_RT, these should use
SA_NODELAY.  The functions called by this ISR are limited to
drivers/oprofile functions.

Patch against 2.6.18-rt8

Signed-off-by: Kevin Hilman <khilman@mvista.com>

Index: dev/arch/arm/oprofile/op_model_xscale.c
===================================================================
--- dev.orig/arch/arm/oprofile/op_model_xscale.c
+++ dev/arch/arm/oprofile/op_model_xscale.c
@@ -14,12 +14,14 @@
  * @author Zwane Mwaikambo
  */

-/* #define DEBUG */
+#define DEBUG
 #include <linux/types.h>
 #include <linux/errno.h>
 #include <linux/sched.h>
 #include <linux/oprofile.h>
 #include <linux/interrupt.h>
+#include <linux/irq.h>
+
 #include <asm/irq.h>
 #include <asm/system.h>

@@ -383,8 +385,9 @@ static int xscale_pmu_start(void)
 {
 	int ret;
 	u32 pmnc = read_pmnc();
+	int irq_flags = SA_INTERRUPT | SA_NODELAY;

-	ret = request_irq(XSCALE_PMU_IRQ, xscale_pmu_interrupt, SA_INTERRUPT,
+	ret = request_irq(XSCALE_PMU_IRQ, xscale_pmu_interrupt, irq_flags,
 			"XScale PMU", (void *)results);

 	if (ret < 0) {

Re: [PATCH -rt] use SA_NODELAY for XScale PMU interrupts

[Kevin Hilman]

Kevin Hilman wrote:
> In the XScale oprofile support, the performance monitoring unit (PMU)
> triggers interrupts and the ISR reads out the performance data.  These
> ISRs are currently set to SA_INTERRUPT.  In order to get accurate
> performance and profiling data under PREEMPT_RT, these should use
> SA_NODELAY.  The functions called by this ISR are limited to
> drivers/oprofile functions.
> 
> Patch against 2.6.18-rt8
> 
> Signed-off-by: Kevin Hilman <khilman@mvista.com>

Resend, without the #define DEBUG.

Index: dev/arch/arm/oprofile/op_model_xscale.c
===================================================================
--- dev.orig/arch/arm/oprofile/op_model_xscale.c
+++ dev/arch/arm/oprofile/op_model_xscale.c
@@ -20,6 +20,8 @@
 #include <linux/sched.h>
 #include <linux/oprofile.h>
 #include <linux/interrupt.h>
+#include <linux/irq.h>
+
 #include <asm/irq.h>
 #include <asm/system.h>

@@ -383,8 +385,9 @@ static int xscale_pmu_start(void)
 {
 	int ret;
 	u32 pmnc = read_pmnc();
+	int irq_flags = SA_INTERRUPT | SA_NODELAY;

-	ret = request_irq(XSCALE_PMU_IRQ, xscale_pmu_interrupt, SA_INTERRUPT,
+	ret = request_irq(XSCALE_PMU_IRQ, xscale_pmu_interrupt, irq_flags,
 			"XScale PMU", (void *)results);

 	if (ret < 0) {

Re: [PATCH -rt] use SA_NODELAY for XScale PMU interrupts

[Arjan van de Ven]

On Fri, 2006-09-08 at 12:22 -0700, Kevin Hilman wrote:
> In the XScale oprofile support, the performance monitoring unit (PMU)
> triggers interrupts and the ISR reads out the performance data.  These
> ISRs are currently set to SA_INTERRUPT.  In order to get accurate
> performance and profiling data under PREEMPT_RT, these should use
> SA_NODELAY.  The functions called by this ISR are limited to
> drivers/oprofile functions.
> 
> Patch against 2.6.18-rt8


hmm I thought the SA_ flags were deprecated ???

Re: [PATCH -rt] use SA_NODELAY for XScale PMU interrupts

[Kevin Hilman]

Arjan van de Ven wrote:
> On Fri, 2006-09-08 at 12:22 -0700, Kevin Hilman wrote:
>> In the XScale oprofile support, the performance monitoring unit (PMU)
>> triggers interrupts and the ISR reads out the performance data.  These
>> ISRs are currently set to SA_INTERRUPT.  In order to get accurate
>> performance and profiling data under PREEMPT_RT, these should use
>> SA_NODELAY.  The functions called by this ISR are limited to
>> drivers/oprofile functions.
>>
>> Patch against 2.6.18-rt8
> 
> hmm I thought the SA_ flags were deprecated ???
> 

Sorry, although I said 2.6.18-rt8, the patch is against 2.6.17-rt8,
where the SA_ flags are still used.

Kevin