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 rmk+kernel@arm.linux.org.uk Suggested-by: Venki Pallipadi venki@google.com Signed-off-by: Dmitry Antipov dmitry.antipov@linaro.org --- Documentation/kernel-parameters.txt | 9 +++++---- 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 ++++++++++++ 8 files changed, 40 insertions(+), 18 deletions(-) create mode 100644 lib/irqtime.c
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 033d4e6..b64a13f 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1719,6 +1719,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
noautogroup Disable scheduler automatic task group creation.
+ noirqtime [X86,ARM] Used to run time disable IRQ_TIME_ACCOUNTING, + should give a negligible performance improvement. + nobats [PPC] Do not use BATs for mapping kernel lowmem on "Classic" PPC cores.
@@ -2636,10 +2639,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted. as the stability checks done at bootup. Used to enable high-resolution timer mode on older hardware, and in virtualized environment. - [x86] noirqtime: Do not use TSC to do irq accounting. - Used to run time disable IRQ_TIME_ACCOUNTING on any - platforms where RDTSC is slow and this accounting - can add overhead. + [x86] noirqtime: obsoleted by "noirqtime" generic option, + see it's documentation for details.
turbografx.map[2|3]= [HW,JOY] TurboGraFX parallel port interface 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);
-
Dmitry Antipov