Generalize CONFIG_IRQ_TIME_ACCOUNTING between X86 and
ARM, move "noirqtime=" option to common debugging code.
For a bit of backward compatibility, X86-specific option
"tsc=noirqtime" is preserved, but issues a warning.
Suggested-by: Russell King <[email protected]>
Suggested-by: Venki Pallipadi <[email protected]>
Signed-off-by: Dmitry Antipov <[email protected]>
---
arch/arm/kernel/sched_clock.c | 3 +++
arch/x86/Kconfig | 11 -----------
arch/x86/kernel/tsc.c | 7 ++++---
include/linux/sched.h | 2 ++
lib/Kconfig.debug | 12 ++++++++++++
lib/Makefile | 2 ++
lib/irqtime.c | 12 ++++++++++++
7 files changed, 35 insertions(+), 14 deletions(-)
create mode 100644 lib/irqtime.c
diff --git a/arch/arm/kernel/sched_clock.c b/arch/arm/kernel/sched_clock.c
index 5416c7c..961bd2d 100644
--- a/arch/arm/kernel/sched_clock.c
+++ b/arch/arm/kernel/sched_clock.c
@@ -144,6 +144,9 @@ void __init setup_sched_clock(u32 (*read)(void), int bits, unsigned long rate)
*/
cd.epoch_ns = 0;
+ if (!no_sched_irq_time)
+ enable_sched_clock_irqtime();
+
pr_debug("Registered %pF as sched_clock source\n", read);
}
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 5bed94e..4759676 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -805,17 +805,6 @@ config SCHED_MC
making when dealing with multi-core CPU chips at a cost of slightly
increased overhead in some places. If unsure say N here.
-config IRQ_TIME_ACCOUNTING
- bool "Fine granularity task level IRQ time accounting"
- default n
- ---help---
- Select this option to enable fine granularity task irq time
- accounting. This is done by reading a timestamp on each
- transitions between softirq and hardirq state, so there can be a
- small performance impact.
-
- If in doubt, say N here.
-
source "kernel/Kconfig.preempt"
config X86_UP_APIC
diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index a62c201..70510a3 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -103,14 +103,15 @@ int __init notsc_setup(char *str)
__setup("notsc", notsc_setup);
-static int no_sched_irq_time;
-
static int __init tsc_setup(char *str)
{
if (!strcmp(str, "reliable"))
tsc_clocksource_reliable = 1;
- if (!strncmp(str, "noirqtime", 9))
+ if (!strncmp(str, "noirqtime", 9)) {
+ printk(KERN_WARNING "tsc: tsc=noirqtime is "
+ "obsolete, use noirqtime instead\n");
no_sched_irq_time = 1;
+ }
return 1;
}
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 7d379a6..b3575b5 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1966,9 +1966,11 @@ extern void sched_clock_idle_wakeup_event(u64 delta_ns);
* The reason for this explicit opt-in is not to have perf penalty with
* slow sched_clocks.
*/
+extern int no_sched_irq_time;
extern void enable_sched_clock_irqtime(void);
extern void disable_sched_clock_irqtime(void);
#else
+#define no_sched_irq_time 1
static inline void enable_sched_clock_irqtime(void) {}
static inline void disable_sched_clock_irqtime(void) {}
#endif
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 8745ac7..236e814 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -299,6 +299,18 @@ config SCHEDSTATS
application, you can say N to avoid the very slight overhead
this adds.
+config IRQ_TIME_ACCOUNTING
+ bool "Fine granularity task level IRQ time accounting"
+ depends on X86 || ARM
+ default n
+ ---help---
+ Select this option to enable fine granularity task irq time
+ accounting. This is done by reading a timestamp on each
+ transitions between softirq and hardirq state, so there can be a
+ small performance impact.
+
+ If in doubt, say N here.
+
config TIMER_STATS
bool "Collect kernel timers statistics"
depends on DEBUG_KERNEL && PROC_FS
diff --git a/lib/Makefile b/lib/Makefile
index 18515f0..44d67d4 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -49,6 +49,8 @@ obj-$(CONFIG_DEBUG_PREEMPT) += smp_processor_id.o
obj-$(CONFIG_DEBUG_LIST) += list_debug.o
obj-$(CONFIG_DEBUG_OBJECTS) += debugobjects.o
+obj-$(CONFIG_IRQ_TIME_ACCOUNTING) += irqtime.o
+
ifneq ($(CONFIG_HAVE_DEC_LOCK),y)
lib-y += dec_and_lock.o
endif
diff --git a/lib/irqtime.c b/lib/irqtime.c
new file mode 100644
index 0000000..10d440d
--- /dev/null
+++ b/lib/irqtime.c
@@ -0,0 +1,12 @@
+#include <linux/kernel.h>
+#include <linux/sched.h>
+
+int no_sched_irq_time;
+
+static int __init irqtime_setup(char *str)
+{
+ no_sched_irq_time = 1;
+ return 1;
+}
+
+__setup("noirqtime", irqtime_setup);
--
1.7.7.6
On Wed, Feb 8, 2012 at 8:08 AM, Dmitry Antipov
<[email protected]> wrote:
> Generalize CONFIG_IRQ_TIME_ACCOUNTING ?between X86 and
> ARM, move "noirqtime=" option to common debugging code.
> For a bit of backward compatibility, X86-specific option
> "tsc=noirqtime" is preserved, but issues a warning.
>
> Suggested-by: Russell King <[email protected]>
> Suggested-by: Venki Pallipadi <[email protected]>
> Signed-off-by: Dmitry Antipov <[email protected]>
> ---
> ?arch/arm/kernel/sched_clock.c | ? ?3 +++
> ?arch/x86/Kconfig ? ? ? ? ? ? ?| ? 11 -----------
> ?arch/x86/kernel/tsc.c ? ? ? ? | ? ?7 ++++---
> ?include/linux/sched.h ? ? ? ? | ? ?2 ++
> ?lib/Kconfig.debug ? ? ? ? ? ? | ? 12 ++++++++++++
> ?lib/Makefile ? ? ? ? ? ? ? ? ?| ? ?2 ++
> ?lib/irqtime.c ? ? ? ? ? ? ? ? | ? 12 ++++++++++++
> ?7 files changed, 35 insertions(+), 14 deletions(-)
> ?create mode 100644 lib/irqtime.c
>
> diff --git a/arch/arm/kernel/sched_clock.c b/arch/arm/kernel/sched_clock.c
> index 5416c7c..961bd2d 100644
> --- a/arch/arm/kernel/sched_clock.c
> +++ b/arch/arm/kernel/sched_clock.c
> @@ -144,6 +144,9 @@ void __init setup_sched_clock(u32 (*read)(void), int bits, unsigned long rate)
> ? ? ? ? */
> ? ? ? ?cd.epoch_ns = 0;
>
> + ? ? ? if (!no_sched_irq_time)
> + ? ? ? ? ? ? ? enable_sched_clock_irqtime();
> +
> ? ? ? ?pr_debug("Registered %pF as sched_clock source\n", read);
> ?}
>
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index 5bed94e..4759676 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -805,17 +805,6 @@ config SCHED_MC
> ? ? ? ? ?making when dealing with multi-core CPU chips at a cost of slightly
> ? ? ? ? ?increased overhead in some places. If unsure say N here.
>
> -config IRQ_TIME_ACCOUNTING
> - ? ? ? bool "Fine granularity task level IRQ time accounting"
> - ? ? ? default n
> - ? ? ? ---help---
> - ? ? ? ? Select this option to enable fine granularity task irq time
> - ? ? ? ? accounting. This is done by reading a timestamp on each
> - ? ? ? ? transitions between softirq and hardirq state, so there can be a
> - ? ? ? ? small performance impact.
> -
> - ? ? ? ? If in doubt, say N here.
> -
> ?source "kernel/Kconfig.preempt"
>
> ?config X86_UP_APIC
> diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
> index a62c201..70510a3 100644
> --- a/arch/x86/kernel/tsc.c
> +++ b/arch/x86/kernel/tsc.c
> @@ -103,14 +103,15 @@ int __init notsc_setup(char *str)
>
> ?__setup("notsc", notsc_setup);
>
> -static int no_sched_irq_time;
> -
> ?static int __init tsc_setup(char *str)
> ?{
> ? ? ? ?if (!strcmp(str, "reliable"))
> ? ? ? ? ? ? ? ?tsc_clocksource_reliable = 1;
> - ? ? ? if (!strncmp(str, "noirqtime", 9))
> + ? ? ? if (!strncmp(str, "noirqtime", 9)) {
> + ? ? ? ? ? ? ? printk(KERN_WARNING "tsc: tsc=noirqtime is "
> + ? ? ? ? ? ? ? ? ? ? ?"obsolete, use noirqtime instead\n");
> ? ? ? ? ? ? ? ?no_sched_irq_time = 1;
> + ? ? ? }
> ? ? ? ?return 1;
> ?}
>
> diff --git a/include/linux/sched.h b/include/linux/sched.h
> index 7d379a6..b3575b5 100644
> --- a/include/linux/sched.h
> +++ b/include/linux/sched.h
> @@ -1966,9 +1966,11 @@ extern void sched_clock_idle_wakeup_event(u64 delta_ns);
> ?* The reason for this explicit opt-in is not to have perf penalty with
> ?* slow sched_clocks.
> ?*/
> +extern int no_sched_irq_time;
> ?extern void enable_sched_clock_irqtime(void);
> ?extern void disable_sched_clock_irqtime(void);
> ?#else
> +#define no_sched_irq_time 1
> ?static inline void enable_sched_clock_irqtime(void) {}
> ?static inline void disable_sched_clock_irqtime(void) {}
> ?#endif
> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
> index 8745ac7..236e814 100644
> --- a/lib/Kconfig.debug
> +++ b/lib/Kconfig.debug
> @@ -299,6 +299,18 @@ config SCHEDSTATS
> ? ? ? ? ?application, you can say N to avoid the very slight overhead
> ? ? ? ? ?this adds.
>
> +config IRQ_TIME_ACCOUNTING
> + ? ? ? bool "Fine granularity task level IRQ time accounting"
> + ? ? ? depends on X86 || ARM
> + ? ? ? default n
> + ? ? ? ---help---
> + ? ? ? ? Select this option to enable fine granularity task irq time
> + ? ? ? ? accounting. This is done by reading a timestamp on each
> + ? ? ? ? transitions between softirq and hardirq state, so there can be a
> + ? ? ? ? small performance impact.
> +
> + ? ? ? ? If in doubt, say N here.
> +
> ?config TIMER_STATS
> ? ? ? ?bool "Collect kernel timers statistics"
> ? ? ? ?depends on DEBUG_KERNEL && PROC_FS
> diff --git a/lib/Makefile b/lib/Makefile
> index 18515f0..44d67d4 100644
> --- a/lib/Makefile
> +++ b/lib/Makefile
> @@ -49,6 +49,8 @@ obj-$(CONFIG_DEBUG_PREEMPT) += smp_processor_id.o
> ?obj-$(CONFIG_DEBUG_LIST) += list_debug.o
> ?obj-$(CONFIG_DEBUG_OBJECTS) += debugobjects.o
>
> +obj-$(CONFIG_IRQ_TIME_ACCOUNTING) += irqtime.o
> +
> ?ifneq ($(CONFIG_HAVE_DEC_LOCK),y)
> ? lib-y += dec_and_lock.o
> ?endif
> diff --git a/lib/irqtime.c b/lib/irqtime.c
> new file mode 100644
> index 0000000..10d440d
> --- /dev/null
> +++ b/lib/irqtime.c
> @@ -0,0 +1,12 @@
> +#include <linux/kernel.h>
> +#include <linux/sched.h>
> +
> +int no_sched_irq_time;
> +
> +static int __init irqtime_setup(char *str)
> +{
> + ? ? ? no_sched_irq_time = 1;
> + ? ? ? return 1;
> +}
> +
> +__setup("noirqtime", irqtime_setup);
> --
One more nit-pick. We need corresponding change in
Documentation/kernel-parameters.txt to deprecate tsc=irqtime and add
this new param.
> 1.7.7.6
>