tracing/ftrace: add the boot tracer (d13744cd) · Commits · 戴 / test

include/linux/ftrace.h

+19 −0

Original line number	Diff line number	Diff line
		@@ -5,6 +5,8 @@

		#include <linux/linkage.h>
		#include <linux/fs.h>
		#include <linux/init.h>
		#include <linux/types.h>

		extern int ftrace_enabled;
		extern int
		@@ -209,4 +211,21 @@ ftrace_init_module(unsigned long start, unsigned long end) { }
		#endif


		struct boot_trace {
		pid_t caller;
		initcall_t func;
		int result;
		unsigned long long duration;
		};

		#ifdef CONFIG_BOOT_TRACER
		extern void trace_boot(struct boot_trace *it);
		extern void start_boot_trace(void);
		#else
		static inline void trace_boot(struct boot_trace *it) { }
		static inline void start_boot_trace(void) { }
		#endif



		#endif /* _LINUX_FTRACE_H */

kernel/trace/trace.h

+4 −0

Original line number	Diff line number	Diff line
		@@ -6,6 +6,7 @@
		#include <linux/sched.h>
		#include <linux/clocksource.h>
		#include <linux/mmiotrace.h>
		#include <linux/ftrace.h>

		enum trace_type {
		__TRACE_FIRST_TYPE = 0,
		@@ -19,6 +20,7 @@ enum trace_type {
		TRACE_SPECIAL,
		TRACE_MMIO_RW,
		TRACE_MMIO_MAP,
		TRACE_BOOT,

		__TRACE_LAST_TYPE
		};
		@@ -30,6 +32,7 @@ struct ftrace_entry {
		unsigned long ip;
		unsigned long parent_ip;
		};
		extern struct tracer boot_tracer;

		/*
		* Context switch trace entry - which task (and prio) we switched from/to:
		@@ -108,6 +111,7 @@ struct trace_field {
		struct print_entry print;
		struct mmiotrace_rw mmiorw;
		struct mmiotrace_map mmiomap;
		struct boot_trace initcall;
		};
		};

kernel/trace/trace_boot.c

0 → 100644

+101 −0

Original line number	Diff line number	Diff line
		/*
		* ring buffer based initcalls tracer
		*
		* Copyright (C) 2008 Frederic Weisbecker <fweisbec@gmail.com>
		*
		*/

		#include <linux/init.h>
		#include <linux/debugfs.h>
		#include <linux/ftrace.h>

		#include "trace.h"

		static struct trace_array *boot_trace;
		static int trace_boot_enabled;


		/* Should be started after do_pre_smp_initcalls() in init/main.c */
		void start_boot_trace(void)
		{
		trace_boot_enabled = 1;
		}

		void stop_boot_trace(struct trace_array *tr)
		{
		trace_boot_enabled = 0;
		}

		static void boot_trace_init(struct trace_array *tr)
		{
		int cpu;
		boot_trace = tr;

		trace_boot_enabled = 0;

		for_each_cpu_mask(cpu, cpu_possible_map)
		tracing_reset(tr->data[cpu]);
		}

		static void boot_trace_ctrl_update(struct trace_array *tr)
		{
		if (tr->ctrl)
		start_boot_trace();
		else
		stop_boot_trace(tr);
		}

		static int initcall_print_line(struct trace_iterator *iter)
		{
		int ret = 1;
		struct trace_entry *entry = iter->ent;
		struct boot_trace *it = &entry->field.initcall;
		struct trace_seq *s = &iter->seq;

		if (iter->ent->type == TRACE_BOOT)
		ret = trace_seq_printf(s, "%pF called from %i "
		"returned %d after %lld msecs\n",
		it->func, it->caller, it->result,
		it->duration);
		if (ret)
		return 1;
		return 0;
		}

		struct tracer boot_tracer __read_mostly =
		{
		.name = "initcall",
		.init = boot_trace_init,
		.reset = stop_boot_trace,
		.ctrl_update = boot_trace_ctrl_update,
		.print_line = initcall_print_line,
		};


		void trace_boot(struct boot_trace *it)
		{
		struct trace_entry *entry;
		struct trace_array_cpu *data;
		unsigned long irq_flags;
		struct trace_array *tr = boot_trace;

		if (!trace_boot_enabled)
		return;

		preempt_disable();
		data = tr->data[smp_processor_id()];

		raw_local_irq_save(irq_flags);
		__raw_spin_lock(&data->lock);

		entry = tracing_get_trace_entry(tr, data);
		tracing_generic_entry_update(entry, 0);
		entry->type = TRACE_BOOT;
		entry->field.initcall = *it;

		__raw_spin_unlock(&data->lock);
		raw_local_irq_restore(irq_flags);
		trace_wake_up();

		preempt_enable();
		}

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