Commit 68e2d17c authored by Peter Zijlstra's avatar Peter Zijlstra
Browse files

trace: Add trace_ipi_send_cpu() 



Because copying cpumasks around when targeting a single CPU is a bit
daft...

Tested-and-reviewed-by: default avatarValentin Schneider <vschneid@redhat.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20230322103004.GA571242%40hirez.programming.kicks-ass.net
parent 68f4ff04

include/linux/smp.h

+3 −3
Original line number Diff line number Diff line
@@ -131,7 +131,7 @@ extern void arch_smp_send_reschedule(int cpu); 
 * callsite IP should be sufficient for root-causing IPIs sent from here.

 */

#define smp_send_reschedule(cpu) ({		  \

	trace_ipi_send_cpumask(cpumask_of(cpu), _RET_IP_, NULL);  \

	trace_ipi_send_cpu(cpu, _RET_IP_, NULL);  \

	arch_smp_send_reschedule(cpu);		  \

})

include/trace/events/ipi.h

+22 −0
Original line number Diff line number Diff line
@@ -35,6 +35,28 @@ TRACE_EVENT(ipi_raise, 
	TP_printk("target_mask=%s (%s)", __get_bitmask(target_cpus), __entry->reason)

);



TRACE_EVENT(ipi_send_cpu,



	TP_PROTO(const unsigned int cpu, unsigned long callsite, void *callback),



	TP_ARGS(cpu, callsite, callback),



	TP_STRUCT__entry(

		__field(unsigned int, cpu)

		__field(void *, callsite)

		__field(void *, callback)

	),



	TP_fast_assign(

		__entry->cpu = cpu;

		__entry->callsite = (void *)callsite;

		__entry->callback = callback;

	),



	TP_printk("cpu=%u callsite=%pS callback=%pS",

		  __entry->cpu, __entry->callsite, __entry->callback)

);



TRACE_EVENT(ipi_send_cpumask,



	TP_PROTO(const struct cpumask *cpumask, unsigned long callsite, void *callback),

kernel/irq_work.c

+2 −4
Original line number Diff line number Diff line
@@ -78,10 +78,8 @@ void __weak arch_irq_work_raise(void) 


static __always_inline void irq_work_raise(struct irq_work *work)

{

	if (trace_ipi_send_cpumask_enabled() && arch_irq_work_has_interrupt())

		trace_ipi_send_cpumask(cpumask_of(smp_processor_id()),

				       _RET_IP_,

				       work->func);

	if (trace_ipi_send_cpu_enabled() && arch_irq_work_has_interrupt())

		trace_ipi_send_cpu(smp_processor_id(), _RET_IP_, work->func);



	arch_irq_work_raise();

}

kernel/sched/core.c

+1 −0
Original line number Diff line number Diff line
@@ -96,6 +96,7 @@ 
#include "../../io_uring/io-wq.h"

#include "../smpboot.h"



EXPORT_TRACEPOINT_SYMBOL_GPL(ipi_send_cpu);

EXPORT_TRACEPOINT_SYMBOL_GPL(ipi_send_cpumask);



/*

kernel/smp.c

+2 −2
Original line number Diff line number Diff line
@@ -107,7 +107,7 @@ static __always_inline void 
send_call_function_single_ipi(int cpu, smp_call_func_t func)

{

	if (call_function_single_prep_ipi(cpu)) {

		trace_ipi_send_cpumask(cpumask_of(cpu), _RET_IP_, func);

		trace_ipi_send_cpu(cpu, _RET_IP_, func);

		arch_send_call_function_single_ipi(cpu);

	}

}
@@ -346,7 +346,7 @@ void __smp_call_single_queue(int cpu, struct llist_node *node) 
	 * even if we haven't sent the smp_call IPI yet (e.g. the stopper

	 * executes migration_cpu_stop() on the remote CPU).

	 */

	if (trace_ipi_send_cpumask_enabled()) {

	if (trace_ipi_send_cpu_enabled()) {

		call_single_data_t *csd;

		smp_call_func_t func;