On Mon, 14 Oct 2013 15:53:27 +0200 Daniel Lezcano <[email protected]> wrote:
> The Inter Processor Interrupt is used on ARM to tell another processor to do > a specific action. This is mainly used to emulate a timer interrupt on an idle > cpu, force a cpu to reschedule or run a function on another processor context. > > Add a tracepoint when raising an IPI and in the entry/exit handler function. > > Signed-off-by: Daniel Lezcano <[email protected]> > --- > arch/arm/include/asm/smp.h | 9 ++++ > arch/arm/kernel/smp.c | 34 ++++++++------ > arch/arm64/include/asm/smp.h | 7 +++ > arch/arm64/kernel/smp.c | 21 +++++++-- > include/trace/events/ipi.h | 106 > ++++++++++++++++++++++++++++++++++++++++++ > 5 files changed, 158 insertions(+), 19 deletions(-) > create mode 100644 include/trace/events/ipi.h > > diff --git a/arch/arm/include/asm/smp.h b/arch/arm/include/asm/smp.h > index a8cae71c..788706c 100644 > --- a/arch/arm/include/asm/smp.h > +++ b/arch/arm/include/asm/smp.h > @@ -18,6 +18,15 @@ > # error "<asm/smp.h> included in non-SMP build" > #endif > > +enum ipi_msg_type { > + IPI_WAKEUP, > + IPI_TIMER, > + IPI_RESCHEDULE, > + IPI_CALL_FUNC, > + IPI_CALL_FUNC_SINGLE, > + IPI_CPU_STOP, > +}; > + > #define raw_smp_processor_id() (current_thread_info()->cpu) > > struct seq_file; > diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c > index 72024ea..9ca8ce8 100644 > --- a/arch/arm/kernel/smp.c > +++ b/arch/arm/kernel/smp.c > @@ -46,6 +46,9 @@ > #include <asm/mach/arch.h> > #include <asm/mpu.h> > > +#define CREATE_TRACE_POINTS > +#include <trace/events/ipi.h> > + > /* > * as from 2.5, kernels no longer have an init_tasks structure > * so we need some other way of telling a new secondary core > @@ -59,15 +62,6 @@ struct secondary_data secondary_data; > */ > volatile int pen_release = -1; > > -enum ipi_msg_type { > - IPI_WAKEUP, > - IPI_TIMER, > - IPI_RESCHEDULE, > - IPI_CALL_FUNC, > - IPI_CALL_FUNC_SINGLE, > - IPI_CPU_STOP, > -}; > - > static DECLARE_COMPLETION(cpu_running); > > static struct smp_operations smp_ops; > @@ -433,19 +427,25 @@ void __init set_smp_cross_call(void (*fn)(const struct > cpumask *, unsigned int)) > smp_cross_call = fn; > } > > +static void ipi_raise(const struct cpumask *mask, int ipinr) > +{ > + trace_ipi_raise(mask, ipinr); > + smp_cross_call(mask, ipinr); > +} > + > void arch_send_call_function_ipi_mask(const struct cpumask *mask) > { > - smp_cross_call(mask, IPI_CALL_FUNC); > + ipi_raise(mask, IPI_CALL_FUNC); > } > > void arch_send_wakeup_ipi_mask(const struct cpumask *mask) > { > - smp_cross_call(mask, IPI_WAKEUP); > + ipi_raise(mask, IPI_WAKEUP); > } > > void arch_send_call_function_single_ipi(int cpu) > { > - smp_cross_call(cpumask_of(cpu), IPI_CALL_FUNC_SINGLE); > + ipi_raise(cpumask_of(cpu), IPI_CALL_FUNC_SINGLE); > } > > static const char *ipi_types[NR_IPI] = { > @@ -487,7 +487,7 @@ u64 smp_irq_stat_cpu(unsigned int cpu) > #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST > void tick_broadcast(const struct cpumask *mask) > { > - smp_cross_call(mask, IPI_TIMER); > + ipi_raise(mask, IPI_TIMER); > } > #endif > > @@ -528,6 +528,8 @@ void handle_IPI(int ipinr, struct pt_regs *regs) > unsigned int cpu = smp_processor_id(); > struct pt_regs *old_regs = set_irq_regs(regs); > > + trace_ipi_handler_entry(ipinr); > + > if (ipinr < NR_IPI) > __inc_irq_stat(cpu, ipi_irqs[ipinr]); > > @@ -571,11 +573,13 @@ void handle_IPI(int ipinr, struct pt_regs *regs) > break; > } > set_irq_regs(old_regs); > + > + trace_ipi_handler_exit(ipinr); > } > > void smp_send_reschedule(int cpu) > { > - smp_cross_call(cpumask_of(cpu), IPI_RESCHEDULE); > + ipi_raise(cpumask_of(cpu), IPI_RESCHEDULE); > } > > void smp_send_stop(void) > @@ -586,7 +590,7 @@ void smp_send_stop(void) > cpumask_copy(&mask, cpu_online_mask); > cpumask_clear_cpu(smp_processor_id(), &mask); > if (!cpumask_empty(&mask)) > - smp_cross_call(&mask, IPI_CPU_STOP); > + ipi_raise(&mask, IPI_CPU_STOP); > > /* Wait up to one second for other CPUs to stop */ > timeout = USEC_PER_SEC; > diff --git a/arch/arm64/include/asm/smp.h b/arch/arm64/include/asm/smp.h > index 4b8023c..7ebaa3a 100644 > --- a/arch/arm64/include/asm/smp.h > +++ b/arch/arm64/include/asm/smp.h > @@ -24,6 +24,13 @@ > # error "<asm/smp.h> included in non-SMP build" > #endif > > +enum ipi_msg_type { > + IPI_RESCHEDULE, > + IPI_CALL_FUNC, > + IPI_CALL_FUNC_SINGLE, > + IPI_CPU_STOP, > +}; > + > #define raw_smp_processor_id() (current_thread_info()->cpu) > > struct seq_file; > diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c > index 78db90d..c987b9f 100644 > --- a/arch/arm64/kernel/smp.c > +++ b/arch/arm64/kernel/smp.c > @@ -48,6 +48,9 @@ > #include <asm/tlbflush.h> > #include <asm/ptrace.h> > > +#define CREATE_TRACE_POINTS > +#include <trace/events/ipi.h> > + > /* > * as from 2.5, kernels no longer have an init_tasks structure > * so we need some other way of telling a new secondary core > @@ -426,14 +429,20 @@ void __init set_smp_cross_call(void (*fn)(const struct > cpumask *, unsigned int)) > smp_cross_call = fn; > } > > +static void ipi_raise(const struct cpumask *mask, int ipinr) > +{ > + trace_ipi_raise(mask, ipinr); > + smp_cross_call(mask, ipinr); > +} > + > void arch_send_call_function_ipi_mask(const struct cpumask *mask) > { > - smp_cross_call(mask, IPI_CALL_FUNC); > + ipi_raise(mask, IPI_CALL_FUNC); > } > > void arch_send_call_function_single_ipi(int cpu) > { > - smp_cross_call(cpumask_of(cpu), IPI_CALL_FUNC_SINGLE); > + ipi_raise(cpumask_of(cpu), IPI_CALL_FUNC_SINGLE); > } > > static const char *ipi_types[NR_IPI] = { > @@ -501,6 +510,8 @@ void handle_IPI(int ipinr, struct pt_regs *regs) > unsigned int cpu = smp_processor_id(); > struct pt_regs *old_regs = set_irq_regs(regs); > > + trace_ipi_handler_entry(ipinr); > + > if (ipinr >= IPI_RESCHEDULE && ipinr < IPI_RESCHEDULE + NR_IPI) > __inc_irq_stat(cpu, ipi_irqs[ipinr - IPI_RESCHEDULE]); > > @@ -532,11 +543,13 @@ void handle_IPI(int ipinr, struct pt_regs *regs) > break; > } > set_irq_regs(old_regs); > + > + trace_ipi_handler_exit(ipinr); > } > > void smp_send_reschedule(int cpu) > { > - smp_cross_call(cpumask_of(cpu), IPI_RESCHEDULE); > + ipi_raise(cpumask_of(cpu), IPI_RESCHEDULE); > } > > void smp_send_stop(void) > @@ -549,7 +562,7 @@ void smp_send_stop(void) > cpumask_copy(&mask, cpu_online_mask); > cpu_clear(smp_processor_id(), mask); > > - smp_cross_call(&mask, IPI_CPU_STOP); > + ipi_raise(&mask, IPI_CPU_STOP); > } > > /* Wait up to one second for other CPUs to stop */ > diff --git a/include/trace/events/ipi.h b/include/trace/events/ipi.h > new file mode 100644 > index 0000000..4d6648a > --- /dev/null > +++ b/include/trace/events/ipi.h > @@ -0,0 +1,106 @@ > +#undef TRACE_SYSTEM > +#define TRACE_SYSTEM ipi > + > +#if !defined(_TRACE_IPI_H) || defined(TRACE_HEADER_MULTI_READ) > +#define _TRACE_IPI_H > + > +#include <linux/tracepoint.h> > + > +struct cpumask; > + > +#define ipi_name(ipinr) { IPI_##ipinr, #ipinr } > +#define show_ipi_name(val) \ > + __print_symbolic(val, \ > + ipi_name(WAKEUP), \ > + ipi_name(TIMER), \ > + ipi_name(RESCHEDULE), \ > + ipi_name(CALL_FUNC), \ > + ipi_name(CALL_FUNC_SINGLE), \ > + ipi_name(CPU_STOP)) > + > +/** > + * ipi_handle_entry - called right before the IPI handler > + * @ipinr: the IPI number > + * > + * The @ipinr value must be valid and the action name associated with > + * the IPI value is given in the trace. > + */ > +TRACE_EVENT_CONDITION(ipi_handler_entry, > + > + TP_PROTO(int ipinr), > + > + TP_ARGS(ipinr), > + > + TP_CONDITION(ipinr < NR_IPI && ipinr >= 0), > + > + TP_STRUCT__entry( > + __field(unsigned int, ipinr) > + ), > + > + TP_fast_assign( > + __entry->ipinr = ipinr; > + ), > + > + TP_printk("ipi=%d, name=%s", __entry->ipinr, > + show_ipi_name(__entry->ipinr)) > +); > + > +/** > + * ipi_handle_exit - called right after the IPI handler > + * @ipinr: the IPI number > + * > + * The @ipinr value must be valid and the action name associated with > + * the IPI value is given in the trace. > + */ > +TRACE_EVENT_CONDITION(ipi_handler_exit, > + > + TP_PROTO(int ipinr), > + > + TP_ARGS(ipinr), > + > + TP_CONDITION(ipinr < NR_IPI && ipinr >= 0), > + > + TP_STRUCT__entry( > + __field(int, ipinr) Here you have "int" and above for the "*_entry" you have unsigned int. Is there a difference? If not, you should combine these two into a DECLARE_EVENT_CLASS() and then use DEFINE_EVENT_CONDITION() for the two tracepoints. > + ), > + > + TP_fast_assign( > + __entry->ipinr = ipinr; > + ), > + > + TP_printk("ipi=%d, name=%s", __entry->ipinr, > + show_ipi_name(__entry->ipinr)) > +); > + > +/** > + * ipi_raise - called when a smp cross call is made > + * @ipinr: the IPI number > + * @cpumask: the recipients for the IPI > + * > + * The @ipinr value must be valid and the action name associated with > + * the IPI value is given in the trace. > + */ > +TRACE_EVENT_CONDITION(ipi_raise, > + > + TP_PROTO(const struct cpumask *cpumask, int ipinr), > + > + TP_ARGS(cpumask, ipinr), Why pass in the cpumask if it isn't used? Do you expect to hook something else to the tracepoint? -- Steve > + > + TP_CONDITION(ipinr < NR_IPI && ipinr >= 0), > + > + TP_STRUCT__entry( > + __field(int, ipinr) > + ), > + > + TP_fast_assign( > + __entry->ipinr = ipinr; > + ), > + > + TP_printk("ipi=%d, name=%s", __entry->ipinr, > + show_ipi_name(__entry->ipinr)) > +); > + > +#endif /* _TRACE_IPI_H */ > + > +/* This part must be outside protection */ > +#include <trace/define_trace.h> -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
