linux/include/trace/events/irq.h
Lingutla Chandrasekhar f4bf3ca2e5 softirq: Add trace points for tasklet entry/exit
Tasklets are supposed to finish their work quickly and should not block the
current running process, but it is not guaranteed that they do so.

Currently softirq_entry/exit can be used to analyse the total tasklets
execution time, but that's not helpful to track individual tasklets
execution time. That makes it hard to identify tasklet functions, which
take more time than expected.

Add tasklet_entry/exit trace point support to track individual tasklet
execution.

Trivial usage example:
   # echo 1 > /sys/kernel/debug/tracing/events/irq/tasklet_entry/enable
   # echo 1 > /sys/kernel/debug/tracing/events/irq/tasklet_exit/enable
   # cat /sys/kernel/debug/tracing/trace
 # tracer: nop
 #
 # entries-in-buffer/entries-written: 4/4   #P:4
 #
 #                                _-----=> irqs-off/BH-disabled
 #                               / _----=> need-resched
 #                              | / _---=> hardirq/softirq
 #                              || / _--=> preempt-depth
 #                              ||| / _-=> migrate-disable
 #                              |||| /     delay
 #           TASK-PID     CPU#  |||||  TIMESTAMP  FUNCTION
 #              | |         |   |||||     |         |
           <idle>-0       [003] ..s1.   314.011428: tasklet_entry: tasklet=0xffffa01ef8db2740 function=tcp_tasklet_func
           <idle>-0       [003] ..s1.   314.011432: tasklet_exit: tasklet=0xffffa01ef8db2740 function=tcp_tasklet_func
           <idle>-0       [003] ..s1.   314.017369: tasklet_entry: tasklet=0xffffa01ef8db2740 function=tcp_tasklet_func
           <idle>-0       [003] ..s1.   314.017371: tasklet_exit: tasklet=0xffffa01ef8db2740 function=tcp_tasklet_func

Signed-off-by: Lingutla Chandrasekhar <clingutla@codeaurora.org>
Signed-off-by: J. Avila <elavila@google.com>
Signed-off-by: John Stultz <jstultz@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20230407230526.1685443-1-jstultz@google.com

[elavila: Port to android-mainline]
[jstultz: Rebased to upstream, cut unused trace points, added
 comments for the tracepoints, reworded commit]
2023-04-15 10:17:16 +02:00

214 lines
4.7 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#undef TRACE_SYSTEM
#define TRACE_SYSTEM irq
#if !defined(_TRACE_IRQ_H) || defined(TRACE_HEADER_MULTI_READ)
#define _TRACE_IRQ_H
#include <linux/tracepoint.h>
struct irqaction;
struct softirq_action;
#define SOFTIRQ_NAME_LIST \
softirq_name(HI) \
softirq_name(TIMER) \
softirq_name(NET_TX) \
softirq_name(NET_RX) \
softirq_name(BLOCK) \
softirq_name(IRQ_POLL) \
softirq_name(TASKLET) \
softirq_name(SCHED) \
softirq_name(HRTIMER) \
softirq_name_end(RCU)
#undef softirq_name
#undef softirq_name_end
#define softirq_name(sirq) TRACE_DEFINE_ENUM(sirq##_SOFTIRQ);
#define softirq_name_end(sirq) TRACE_DEFINE_ENUM(sirq##_SOFTIRQ);
SOFTIRQ_NAME_LIST
#undef softirq_name
#undef softirq_name_end
#define softirq_name(sirq) { sirq##_SOFTIRQ, #sirq },
#define softirq_name_end(sirq) { sirq##_SOFTIRQ, #sirq }
#define show_softirq_name(val) \
__print_symbolic(val, SOFTIRQ_NAME_LIST)
/**
* irq_handler_entry - called immediately before the irq action handler
* @irq: irq number
* @action: pointer to struct irqaction
*
* The struct irqaction pointed to by @action contains various
* information about the handler, including the device name,
* @action->name, and the device id, @action->dev_id. When used in
* conjunction with the irq_handler_exit tracepoint, we can figure
* out irq handler latencies.
*/
TRACE_EVENT(irq_handler_entry,
TP_PROTO(int irq, struct irqaction *action),
TP_ARGS(irq, action),
TP_STRUCT__entry(
__field( int, irq )
__string( name, action->name )
),
TP_fast_assign(
__entry->irq = irq;
__assign_str(name, action->name);
),
TP_printk("irq=%d name=%s", __entry->irq, __get_str(name))
);
/**
* irq_handler_exit - called immediately after the irq action handler returns
* @irq: irq number
* @action: pointer to struct irqaction
* @ret: return value
*
* If the @ret value is set to IRQ_HANDLED, then we know that the corresponding
* @action->handler successfully handled this irq. Otherwise, the irq might be
* a shared irq line, or the irq was not handled successfully. Can be used in
* conjunction with the irq_handler_entry to understand irq handler latencies.
*/
TRACE_EVENT(irq_handler_exit,
TP_PROTO(int irq, struct irqaction *action, int ret),
TP_ARGS(irq, action, ret),
TP_STRUCT__entry(
__field( int, irq )
__field( int, ret )
),
TP_fast_assign(
__entry->irq = irq;
__entry->ret = ret;
),
TP_printk("irq=%d ret=%s",
__entry->irq, __entry->ret ? "handled" : "unhandled")
);
DECLARE_EVENT_CLASS(softirq,
TP_PROTO(unsigned int vec_nr),
TP_ARGS(vec_nr),
TP_STRUCT__entry(
__field( unsigned int, vec )
),
TP_fast_assign(
__entry->vec = vec_nr;
),
TP_printk("vec=%u [action=%s]", __entry->vec,
show_softirq_name(__entry->vec))
);
/**
* softirq_entry - called immediately before the softirq handler
* @vec_nr: softirq vector number
*
* When used in combination with the softirq_exit tracepoint
* we can determine the softirq handler routine.
*/
DEFINE_EVENT(softirq, softirq_entry,
TP_PROTO(unsigned int vec_nr),
TP_ARGS(vec_nr)
);
/**
* softirq_exit - called immediately after the softirq handler returns
* @vec_nr: softirq vector number
*
* When used in combination with the softirq_entry tracepoint
* we can determine the softirq handler routine.
*/
DEFINE_EVENT(softirq, softirq_exit,
TP_PROTO(unsigned int vec_nr),
TP_ARGS(vec_nr)
);
/**
* softirq_raise - called immediately when a softirq is raised
* @vec_nr: softirq vector number
*
* When used in combination with the softirq_entry tracepoint
* we can determine the softirq raise to run latency.
*/
DEFINE_EVENT(softirq, softirq_raise,
TP_PROTO(unsigned int vec_nr),
TP_ARGS(vec_nr)
);
DECLARE_EVENT_CLASS(tasklet,
TP_PROTO(struct tasklet_struct *t, void *func),
TP_ARGS(t, func),
TP_STRUCT__entry(
__field( void *, tasklet)
__field( void *, func)
),
TP_fast_assign(
__entry->tasklet = t;
__entry->func = func;
),
TP_printk("tasklet=%ps function=%ps", __entry->tasklet, __entry->func)
);
/**
* tasklet_entry - called immediately before the tasklet is run
* @t: tasklet pointer
* @func: tasklet callback or function being run
*
* Used to find individual tasklet execution time
*/
DEFINE_EVENT(tasklet, tasklet_entry,
TP_PROTO(struct tasklet_struct *t, void *func),
TP_ARGS(t, func)
);
/**
* tasklet_exit - called immediately after the tasklet is run
* @t: tasklet pointer
* @func: tasklet callback or function being run
*
* Used to find individual tasklet execution time
*/
DEFINE_EVENT(tasklet, tasklet_exit,
TP_PROTO(struct tasklet_struct *t, void *func),
TP_ARGS(t, func)
);
#endif /* _TRACE_IRQ_H */
/* This part must be outside protection */
#include <trace/define_trace.h>