Message-ID: <A5ED84D3BB3A384992CBB9C77DEDA4D41384F5FD@USINDEM103.corp.hds.com>
Date:	Wed, 12 Sep 2012 00:00:19 +0000
From:	Seiji Aguchi <seiji.aguchi@....com>
To:	"Thomas Gleixner (tglx@...utronix.de)" <tglx@...utronix.de>
CC:	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"rostedt@...dmis.org" <rostedt@...dmis.org>,
	"'mingo@...e.hu' (mingo@...e.hu)" <mingo@...e.hu>,
	"x86@...nel.org" <x86@...nel.org>,
	"dle-develop@...ts.sourceforge.net" 
	<dle-develop@...ts.sourceforge.net>,
	Satoru Moriya <satoru.moriya@....com>
Subject: RE: [Resend][PATCH V3] trace,x86: add x86 irq vector tracepoints

Thomas,

Please review my patch as we talked in Plumbers.

Seiji

> -----Original Message-----
> From: Seiji Aguchi
> Sent: Friday, August 24, 2012 11:22 AM
> To: Thomas Gleixner (tglx@...utronix.de)
> Cc: linux-kernel@...r.kernel.org; rostedt@...dmis.org; 'mingo@...e.hu' (mingo@...e.hu); x86@...nel.org; dle-
> develop@...ts.sourceforge.net; Satoru Moriya
> Subject: [Resend][PATCH V3] trace,x86: add x86 irq vector tracepoints
> 
> Tomas,
> 
> It is helpful if you can review this patch.
> 
> Change log
>  v2 -> v3
>  - Remove an invalidate_tlb_vector event because it was replaced by a call function vector
>    in a following commit.
>    http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commit;h=52aec3308db85f4e9f5c8b9f5dc4fbd0138c6fa4
> 
>  v1 -> v2
>  - Modify variable name from irq to vector.
>  - Merge arch-specific tracepoints below to an arch_irq_vector_entry/exit.
>    - error_apic_vector
>    - thermal_apic_vector
>    - threshold_apic_vector
>    - spurious_apic_vector
>    - x86_platform_ipi_vector
> 
> As Vaibhav explained in the thread below, tracepoints for irq vectors are useful.
> 
> http://www.spinics.net/lists/mm-commits/msg85707.html
> 
> <snip>
> The current interrupt traces from irq_handler_entry and irq_handler_exit provide when an interrupt is handled.  They provide good
> data about when the system has switched to kernel space and how it affects the currently running processes.
> 
> There are some IRQ vectors which trigger the system into kernel space, which are not handled in generic IRQ handlers.  Tracing such
> events gives us the information about IRQ interaction with other system events.
> 
> The trace also tells where the system is spending its time.  We want to know which cores are handling interrupts and how they are
> affecting other processes in the system.  Also, the trace provides information about when the cores are idle and which interrupts are
> changing that state.
> <snip>
> 
> On the other hand, my usecase is tracing just local timer event and getting a value of instruction pointer.
> 
>   I suggested to add an argument local timer event to get instruction pointer before.
>   But there is another way to get it with external module like systemtap.
>   So, I don't need to add any argument to irq vector tracepoints now.
> 
> Vaibhav's patch shared a trace point ,irq_vector_entry/irq_vector_exit, in all events.
> But there is an above use case to trace specific irq_vector rather than tracing all events.
> In this case, we are concerned about overhead due to unwanted events.
> 
> This patch modifies Vaibhav's one as follows.
>  - Separate generic, and across-architecture tracepoints to enable independently.
>    - nmi_vector
>    - local_timer_vector
>    - reschedule_vector
>    - call_function_vector
>    - call_function_single_vector
>    - irq_work_entry_vector
> 
>  - Rename architecture-specific tracepoints from irq_vector_entry/exit to
>    arch_irq_vector_entry/exit.
>    - error_apic_vector
>    - thermal_apic_vector
>    - threshold_apic_vector
>    - spurious_apic_vector
>    - x86_platform_ipi_vector
> 
>    Those x86 specific ones are not really frequently raised vectors, so
>    enabling them all won't affect performance and readability of the
>    traces too much.
> 
>  Signed-off-by: Seiji Aguchi <seiji.aguchi@....com>
> 
> ---
>  arch/x86/include/asm/irq_vectors.h       |    9 ++
>  arch/x86/kernel/apic/apic.c              |    7 +
>  arch/x86/kernel/cpu/mcheck/therm_throt.c |    3 +
>  arch/x86/kernel/cpu/mcheck/threshold.c   |    3 +
>  arch/x86/kernel/irq.c                    |    5 +
>  arch/x86/kernel/irq_work.c               |    3 +
>  arch/x86/kernel/nmi.c                    |    3 +
>  arch/x86/kernel/smp.c                    |    7 +
>  include/trace/events/irq_vectors.h       |  209 ++++++++++++++++++++++++++++++
>  9 files changed, 249 insertions(+), 0 deletions(-)  create mode 100644 include/trace/events/irq_vectors.h
> 
> diff --git a/arch/x86/include/asm/irq_vectors.h b/arch/x86/include/asm/irq_vectors.h
> index 1508e51..510ced5 100644
> --- a/arch/x86/include/asm/irq_vectors.h
> +++ b/arch/x86/include/asm/irq_vectors.h
> @@ -158,4 +158,13 @@ static inline int invalid_vm86_irq(int irq)
>  # define NR_IRQS			NR_IRQS_LEGACY
>  #endif
> 
> +#define irq_vector_name(vector) { vector, #vector }
> +
> +#define irq_vector_name_table						\
> +			irq_vector_name(ERROR_APIC_VECTOR),		\
> +			irq_vector_name(THERMAL_APIC_VECTOR),		\
> +			irq_vector_name(THRESHOLD_APIC_VECTOR),		\
> +			irq_vector_name(SPURIOUS_APIC_VECTOR),		\
> +			irq_vector_name(X86_PLATFORM_IPI_VECTOR)
> +
>  #endif /* _ASM_X86_IRQ_VECTORS_H */
> diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index 24deb30..b9cdd8f 100644
> --- a/arch/x86/kernel/apic/apic.c
> +++ b/arch/x86/kernel/apic/apic.c
> @@ -34,6 +34,7 @@
>  #include <linux/dmi.h>
>  #include <linux/smp.h>
>  #include <linux/mm.h>
> +#include <trace/events/irq_vectors.h>
> 
>  #include <asm/irq_remapping.h>
>  #include <asm/perf_event.h>
> @@ -895,7 +896,9 @@ void __irq_entry smp_apic_timer_interrupt(struct pt_regs *regs)
>  	 */
>  	irq_enter();
>  	exit_idle();
> +	trace_local_timer_entry(LOCAL_TIMER_VECTOR);
>  	local_apic_timer_interrupt();
> +	trace_local_timer_exit(LOCAL_TIMER_VECTOR);
>  	irq_exit();
> 
>  	set_irq_regs(old_regs);
> @@ -1881,6 +1884,7 @@ void smp_spurious_interrupt(struct pt_regs *regs)
> 
>  	irq_enter();
>  	exit_idle();
> +	trace_arch_irq_vector_entry(SPURIOUS_APIC_VECTOR);
>  	/*
>  	 * Check if this really is a spurious interrupt and ACK it
>  	 * if it is a vectored one.  Just in case...
> @@ -1895,6 +1899,7 @@ void smp_spurious_interrupt(struct pt_regs *regs)
>  	/* see sw-dev-man vol 3, chapter 7.4.13.5 */
>  	pr_info("spurious APIC interrupt on CPU#%d, "
>  		"should never happen.\n", smp_processor_id());
> +	trace_arch_irq_vector_exit(SPURIOUS_APIC_VECTOR);
>  	irq_exit();
>  }
> 
> @@ -1918,6 +1923,7 @@ void smp_error_interrupt(struct pt_regs *regs)
> 
>  	irq_enter();
>  	exit_idle();
> +	trace_arch_irq_vector_entry(ERROR_APIC_VECTOR);
>  	/* First tickle the hardware, only then report what went on. -- REW */
>  	v0 = apic_read(APIC_ESR);
>  	apic_write(APIC_ESR, 0);
> @@ -1938,6 +1944,7 @@ void smp_error_interrupt(struct pt_regs *regs)
> 
>  	apic_printk(APIC_DEBUG, KERN_CONT "\n");
> 
> +	trace_arch_irq_vector_exit(ERROR_APIC_VECTOR);
>  	irq_exit();
>  }
> 
> diff --git a/arch/x86/kernel/cpu/mcheck/therm_throt.c b/arch/x86/kernel/cpu/mcheck/therm_throt.c
> index 47a1870..63c2cc8 100644
> --- a/arch/x86/kernel/cpu/mcheck/therm_throt.c
> +++ b/arch/x86/kernel/cpu/mcheck/therm_throt.c
> @@ -23,6 +23,7 @@
>  #include <linux/init.h>
>  #include <linux/smp.h>
>  #include <linux/cpu.h>
> +#include <trace/events/irq_vectors.h>
> 
>  #include <asm/processor.h>
>  #include <asm/apic.h>
> @@ -382,8 +383,10 @@ asmlinkage void smp_thermal_interrupt(struct pt_regs *regs)  {
>  	irq_enter();
>  	exit_idle();
> +	trace_arch_irq_vector_entry(THERMAL_APIC_VECTOR);
>  	inc_irq_stat(irq_thermal_count);
>  	smp_thermal_vector();
> +	trace_arch_irq_vector_exit(THERMAL_APIC_VECTOR);
>  	irq_exit();
>  	/* Ack only at the end to avoid potential reentry */
>  	ack_APIC_irq();
> diff --git a/arch/x86/kernel/cpu/mcheck/threshold.c b/arch/x86/kernel/cpu/mcheck/threshold.c
> index aa578ca..de74768 100644
> --- a/arch/x86/kernel/cpu/mcheck/threshold.c
> +++ b/arch/x86/kernel/cpu/mcheck/threshold.c
> @@ -3,6 +3,7 @@
>   */
>  #include <linux/interrupt.h>
>  #include <linux/kernel.h>
> +#include <trace/events/irq_vectors.h>
> 
>  #include <asm/irq_vectors.h>
>  #include <asm/apic.h>
> @@ -21,8 +22,10 @@ asmlinkage void smp_threshold_interrupt(void)  {
>  	irq_enter();
>  	exit_idle();
> +	trace_arch_irq_vector_entry(THRESHOLD_APIC_VECTOR);
>  	inc_irq_stat(irq_threshold_count);
>  	mce_threshold_vector();
> +	trace_arch_irq_vector_exit(THRESHOLD_APIC_VECTOR);
>  	irq_exit();
>  	/* Ack only at the end to avoid potential reentry */
>  	ack_APIC_irq();
> diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c index 1f5f1d5..f4d7344 100644
> --- a/arch/x86/kernel/irq.c
> +++ b/arch/x86/kernel/irq.c
> @@ -18,6 +18,9 @@
>  #include <asm/mce.h>
>  #include <asm/hw_irq.h>
> 
> +#define CREATE_TRACE_POINTS
> +#include <trace/events/irq_vectors.h>
> +
>  atomic_t irq_err_count;
> 
>  /* Function pointer for generic interrupt vector handling */ @@ -218,11 +221,13 @@ void smp_x86_platform_ipi(struct pt_regs *regs)
> 
>  	exit_idle();
> 
> +	trace_arch_irq_vector_entry(X86_PLATFORM_IPI_VECTOR);
>  	inc_irq_stat(x86_platform_ipis);
> 
>  	if (x86_platform_ipi_callback)
>  		x86_platform_ipi_callback();
> 
> +	trace_arch_irq_vector_exit(X86_PLATFORM_IPI_VECTOR);
>  	irq_exit();
> 
>  	set_irq_regs(old_regs);
> diff --git a/arch/x86/kernel/irq_work.c b/arch/x86/kernel/irq_work.c index ca8f703..2cf7505 100644
> --- a/arch/x86/kernel/irq_work.c
> +++ b/arch/x86/kernel/irq_work.c
> @@ -8,13 +8,16 @@
>  #include <linux/irq_work.h>
>  #include <linux/hardirq.h>
>  #include <asm/apic.h>
> +#include <trace/events/irq_vectors.h>
> 
>  void smp_irq_work_interrupt(struct pt_regs *regs)  {
>  	irq_enter();
>  	ack_APIC_irq();
> +	trace_irq_work_entry(IRQ_WORK_VECTOR);
>  	inc_irq_stat(apic_irq_work_irqs);
>  	irq_work_run();
> +	trace_irq_work_exit(IRQ_WORK_VECTOR);
>  	irq_exit();
>  }
> 
> diff --git a/arch/x86/kernel/nmi.c b/arch/x86/kernel/nmi.c index f84f5c5..cc57aba 100644
> --- a/arch/x86/kernel/nmi.c
> +++ b/arch/x86/kernel/nmi.c
> @@ -28,6 +28,7 @@
>  #include <asm/mach_traps.h>
>  #include <asm/nmi.h>
>  #include <asm/x86_init.h>
> +#include <trace/events/irq_vectors.h>
> 
>  struct nmi_desc {
>  	spinlock_t lock;
> @@ -482,12 +483,14 @@ do_nmi(struct pt_regs *regs, long error_code)
>  	nmi_nesting_preprocess(regs);
> 
>  	nmi_enter();
> +	trace_nmi_entry(NMI_VECTOR);
> 
>  	inc_irq_stat(__nmi_count);
> 
>  	if (!ignore_nmis)
>  		default_do_nmi(regs);
> 
> +	trace_nmi_exit(NMI_VECTOR);
>  	nmi_exit();
> 
>  	/* On i386, may loop back to preprocess */ diff --git a/arch/x86/kernel/smp.c b/arch/x86/kernel/smp.c index
> 48d2b7d..5b2d6de 100644
> --- a/arch/x86/kernel/smp.c
> +++ b/arch/x86/kernel/smp.c
> @@ -23,6 +23,7 @@
>  #include <linux/interrupt.h>
>  #include <linux/cpu.h>
>  #include <linux/gfp.h>
> +#include <trace/events/irq_vectors.h>
> 
>  #include <asm/mtrr.h>
>  #include <asm/tlbflush.h>
> @@ -252,8 +253,10 @@ finish:
>  void smp_reschedule_interrupt(struct pt_regs *regs)  {
>  	ack_APIC_irq();
> +	trace_reschedule_entry(RESCHEDULE_VECTOR);
>  	inc_irq_stat(irq_resched_count);
>  	scheduler_ipi();
> +	trace_reschedule_exit(RESCHEDULE_VECTOR);
>  	/*
>  	 * KVM uses this interrupt to force a cpu out of guest mode
>  	 */
> @@ -263,8 +266,10 @@ void smp_call_function_interrupt(struct pt_regs *regs)  {
>  	ack_APIC_irq();
>  	irq_enter();
> +	trace_call_function_entry(CALL_FUNCTION_VECTOR);
>  	generic_smp_call_function_interrupt();
>  	inc_irq_stat(irq_call_count);
> +	trace_call_function_exit(CALL_FUNCTION_VECTOR);
>  	irq_exit();
>  }
> 
> @@ -272,8 +277,10 @@ void smp_call_function_single_interrupt(struct pt_regs *regs)  {
>  	ack_APIC_irq();
>  	irq_enter();
> +	trace_call_function_single_entry(CALL_FUNCTION_SINGLE_VECTOR);
>  	generic_smp_call_function_single_interrupt();
>  	inc_irq_stat(irq_call_count);
> +	trace_call_function_single_exit(CALL_FUNCTION_SINGLE_VECTOR);
>  	irq_exit();
>  }
> 
> diff --git a/include/trace/events/irq_vectors.h b/include/trace/events/irq_vectors.h
> new file mode 100644
> index 0000000..fffe0c0
> --- /dev/null
> +++ b/include/trace/events/irq_vectors.h
> @@ -0,0 +1,209 @@
> +#undef TRACE_SYSTEM
> +#define TRACE_SYSTEM irq_vectors
> +
> +#if !defined(_TRACE_IRQ_VECTORS_H) || defined(TRACE_HEADER_MULTI_READ)
> +#define _TRACE_IRQ_VECTORS_H
> +
> +#include <linux/tracepoint.h>
> +#include <asm/irq.h>
> +
> +#ifndef irq_vector_name_table
> +#define irq_vector_name_table { -1, NULL } #endif
> +
> +
> +/*
> + * This class is used by generic ,cross-architecture tracepoints.
> + */
> +DECLARE_EVENT_CLASS(irq_vector,
> +
> +	TP_PROTO(int vector),
> +
> +	TP_ARGS(vector),
> +
> +	TP_STRUCT__entry(
> +		__field(	int,	vector	)
> +	),
> +
> +	TP_fast_assign(
> +		__entry->vector = vector;
> +	),
> +
> +	TP_printk("vector=%d", __entry->vector) );
> +
> +/*
> + * nmi_entry - called before enterring a nmi vector handler  */
> +DEFINE_EVENT(irq_vector, nmi_entry,
> +
> +	TP_PROTO(int vector),
> +
> +	TP_ARGS(vector)
> +);
> +
> +/*
> + * nmi_exit - called immediately after the interrupt vector
> + * handler returns
> + */
> +DEFINE_EVENT(irq_vector, nmi_exit,
> +
> +	TP_PROTO(int vector),
> +
> +	TP_ARGS(vector)
> +);
> +
> +/*
> + * local_timer_entry - called before enterring a local timer interrupt
> + * vector handler
> + */
> +DEFINE_EVENT(irq_vector, local_timer_entry,
> +
> +	TP_PROTO(int vector),
> +
> +	TP_ARGS(vector)
> +);
> +
> +/*
> + * local_timer_exit - called immediately after the interrupt vector
> + * handler returns
> + */
> +DEFINE_EVENT(irq_vector, local_timer_exit,
> +
> +	TP_PROTO(int vector),
> +
> +	TP_ARGS(vector)
> +);
> +
> +/*
> + * reschedule_entry - called before enterring a reschedule vector
> +handler  */ DEFINE_EVENT(irq_vector, reschedule_entry,
> +
> +	TP_PROTO(int vector),
> +
> +	TP_ARGS(vector)
> +);
> +
> +/*
> + * reschedule_exit - called immediately after the interrupt vector
> + * handler returns
> + */
> +DEFINE_EVENT(irq_vector, reschedule_exit,
> +
> +	TP_PROTO(int vector),
> +
> +	TP_ARGS(vector)
> +);
> +
> +/*
> + * call_function_entry - called before enterring a call function
> + *			 vector handler
> + */
> +DEFINE_EVENT(irq_vector, call_function_entry,
> +
> +	TP_PROTO(int vector),
> +
> +	TP_ARGS(vector)
> +);
> +
> +/*
> + * call_function_exit - called immediately after the interrupt vector
> + * handler returns
> + */
> +DEFINE_EVENT(irq_vector, call_function_exit,
> +
> +	TP_PROTO(int vector),
> +
> +	TP_ARGS(vector)
> +);
> +
> +/*
> + * call_function_single_entry - called before enterring a call function
> + * single vector handler
> + */
> +DEFINE_EVENT(irq_vector, call_function_single_entry,
> +
> +	TP_PROTO(int vector),
> +
> +	TP_ARGS(vector)
> +);
> +
> +/*
> + * call_function_single_exit - called immediately after the interrupt
> +vector
> + * handler returns
> + */
> +DEFINE_EVENT(irq_vector, call_function_single_exit,
> +
> +	TP_PROTO(int vector),
> +
> +	TP_ARGS(vector)
> +);
> +
> +/*
> + * irq_work_entry - called before enterring an irq work vector handler
> +*/ DEFINE_EVENT(irq_vector, irq_work_entry,
> +
> +	TP_PROTO(int vector),
> +
> +	TP_ARGS(vector)
> +);
> +
> +/*
> + * irq_work_exit - called immediately after the interrupt vector
> + * handler returns
> + */
> +DEFINE_EVENT(irq_vector, irq_work_exit,
> +
> +	TP_PROTO(int vector),
> +
> +	TP_ARGS(vector)
> +);
> +
> +/*
> + * This class is used by arch-specific tracepoints.
> + */
> +DECLARE_EVENT_CLASS(arch_irq_vector,
> +
> +	TP_PROTO(int vector),
> +
> +	TP_ARGS(vector),
> +
> +	TP_STRUCT__entry(
> +		__field(	int,	vector	)
> +	),
> +
> +	TP_fast_assign(
> +		__entry->vector = vector;
> +	),
> +
> +	TP_printk("vector=%d name=%s", __entry->vector,
> +		__print_symbolic(__entry->vector, irq_vector_name_table)) );
> +
> +/*
> + * arch_irq_vector_entry - called before enterring a interrupt vector
> +handler  */ DEFINE_EVENT(arch_irq_vector, arch_irq_vector_entry,
> +
> +	TP_PROTO(int vector),
> +
> +	TP_ARGS(vector)
> +);
> +
> +/*
> + * arch_irq_vector_exit - called immediately after the interrupt vector
> + * handler returns
> + */
> +DEFINE_EVENT(arch_irq_vector, arch_irq_vector_exit,
> +
> +	TP_PROTO(int vector),
> +
> +	TP_ARGS(vector)
> +);
> +
> +#endif /*  _TRACE_IRQ_VECTORS_H */
> +
> +/* This part must be outside protection */ #include
> +<trace/define_trace.h>
> -- 1.7.1
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Powered by blists - more mailing lists