tracing: make sched_switch stop/start light weight
[safe/jmp/linux-2.6] / kernel / trace / trace.h
index 7b0518a..26a7a28 100644 (file)
@@ -20,6 +20,7 @@ enum trace_type {
        TRACE_WAKE,
        TRACE_STACK,
        TRACE_PRINT,
+       TRACE_BPRINT,
        TRACE_SPECIAL,
        TRACE_MMIO_RW,
        TRACE_MMIO_MAP,
@@ -30,6 +31,8 @@ enum trace_type {
        TRACE_GRAPH_ENT,
        TRACE_USER_STACK,
        TRACE_HW_BRANCHES,
+       TRACE_SYSCALL_ENTER,
+       TRACE_SYSCALL_EXIT,
        TRACE_KMEM_ALLOC,
        TRACE_KMEM_FREE,
        TRACE_POWER,
@@ -115,8 +118,16 @@ struct userstack_entry {
 };
 
 /*
- * ftrace_printk entry:
+ * trace_printk entry:
  */
+struct bprint_entry {
+       struct trace_entry      ent;
+       unsigned long           ip;
+       int                     depth;
+       const char              *fmt;
+       u32                     buf[];
+};
+
 struct print_entry {
        struct trace_entry      ent;
        unsigned long           ip;
@@ -195,7 +206,7 @@ struct kmemtrace_free_entry {
  * trace_flag_type is an enumeration that holds different
  * states when a trace occurs. These are:
  *  IRQS_OFF           - interrupts were disabled
- *  IRQS_NOSUPPORT     - arch does not support irqs_disabled_flags
+ *  IRQS_NOSUPPORT     - arch does not support irqs_disabled_flags
  *  NEED_RESCED                - reschedule is requested
  *  HARDIRQ            - inside an interrupt handler
  *  SOFTIRQ            - inside a softirq handler
@@ -217,6 +228,7 @@ enum trace_flag_type {
  */
 struct trace_array_cpu {
        atomic_t                disabled;
+       void                    *buffer_page;   /* ring buffer spare */
 
        /* these fields get copied into max-trace: */
        unsigned long           trace_idx;
@@ -284,6 +296,7 @@ extern void __ftrace_bad_type(void);
                IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);   \
                IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
                IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);   \
+               IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT); \
                IF_ASSIGN(var, ent, struct special_entry, 0);           \
                IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,          \
                          TRACE_MMIO_RW);                               \
@@ -297,7 +310,7 @@ extern void __ftrace_bad_type(void);
                IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,      \
                          TRACE_GRAPH_RET);             \
                IF_ASSIGN(var, ent, struct hw_branch_entry, TRACE_HW_BRANCHES);\
-               IF_ASSIGN(var, ent, struct trace_power, TRACE_POWER); \
+               IF_ASSIGN(var, ent, struct trace_power, TRACE_POWER); \
                IF_ASSIGN(var, ent, struct kmemtrace_alloc_entry,       \
                          TRACE_KMEM_ALLOC);    \
                IF_ASSIGN(var, ent, struct kmemtrace_free_entry,        \
@@ -320,8 +333,8 @@ enum print_line_t {
  * flags value in struct tracer_flags.
  */
 struct tracer_opt {
-       const char      *name; /* Will appear on the trace_options file */
-       u32             bit; /* Mask assigned in val field in tracer_flags */
+       const char      *name; /* Will appear on the trace_options file */
+       u32             bit; /* Mask assigned in val field in tracer_flags */
 };
 
 /*
@@ -330,29 +343,51 @@ struct tracer_opt {
  */
 struct tracer_flags {
        u32                     val;
-       struct tracer_opt       *opts;
+       struct tracer_opt       *opts;
 };
 
 /* Makes more easy to define a tracer opt */
 #define TRACER_OPT(s, b)       .name = #s, .bit = b
 
 
-/*
- * A specific tracer, represented by methods that operate on a trace array:
+/**
+ * struct tracer - a specific tracer and its callbacks to interact with debugfs
+ * @name: the name chosen to select it on the available_tracers file
+ * @init: called when one switches to this tracer (echo name > current_tracer)
+ * @reset: called when one switches to another tracer
+ * @start: called when tracing is unpaused (echo 1 > tracing_enabled)
+ * @stop: called when tracing is paused (echo 0 > tracing_enabled)
+ * @open: called when the trace file is opened
+ * @pipe_open: called when the trace_pipe file is opened
+ * @wait_pipe: override how the user waits for traces on trace_pipe
+ * @close: called when the trace file is released
+ * @read: override the default read callback on trace_pipe
+ * @splice_read: override the default splice_read callback on trace_pipe
+ * @selftest: selftest to run on boot (see trace_selftest.c)
+ * @print_headers: override the first lines that describe your columns
+ * @print_line: callback that prints a trace
+ * @set_flag: signals one of your private flags changed (trace_options file)
+ * @flags: your private flags
  */
 struct tracer {
        const char              *name;
-       /* Your tracer should raise a warning if init fails */
        int                     (*init)(struct trace_array *tr);
        void                    (*reset)(struct trace_array *tr);
        void                    (*start)(struct trace_array *tr);
        void                    (*stop)(struct trace_array *tr);
        void                    (*open)(struct trace_iterator *iter);
        void                    (*pipe_open)(struct trace_iterator *iter);
+       void                    (*wait_pipe)(struct trace_iterator *iter);
        void                    (*close)(struct trace_iterator *iter);
        ssize_t                 (*read)(struct trace_iterator *iter,
                                        struct file *filp, char __user *ubuf,
                                        size_t cnt, loff_t *ppos);
+       ssize_t                 (*splice_read)(struct trace_iterator *iter,
+                                              struct file *filp,
+                                              loff_t *ppos,
+                                              struct pipe_inode_info *pipe,
+                                              size_t len,
+                                              unsigned int flags);
 #ifdef CONFIG_FTRACE_STARTUP_TEST
        int                     (*selftest)(struct tracer *trace,
                                            struct trace_array *tr);
@@ -363,7 +398,7 @@ struct tracer {
        int                     (*set_flag)(u32 old_flags, u32 bit, int set);
        struct tracer           *next;
        int                     print_max;
-       struct tracer_flags     *flags;
+       struct tracer_flags     *flags;
        struct tracer_stat      *stats;
 };
 
@@ -373,6 +408,16 @@ struct trace_seq {
        unsigned int            readpos;
 };
 
+static inline void
+trace_seq_init(struct trace_seq *s)
+{
+       s->len = 0;
+       s->readpos = 0;
+}
+
+
+#define TRACE_PIPE_ALL_CPU     -1
+
 /*
  * Trace iterator - used by printout routines who present trace
  * results to users and which routines might sleep, etc:
@@ -381,6 +426,8 @@ struct trace_iterator {
        struct trace_array      *tr;
        struct tracer           *trace;
        void                    *private;
+       int                     cpu_file;
+       struct mutex            mutex;
        struct ring_buffer_iter *buffer_iter[NR_CPUS];
 
        /* The below is zeroed out in pipe_read */
@@ -416,6 +463,12 @@ void trace_buffer_unlock_commit(struct trace_array *tr,
                                struct ring_buffer_event *event,
                                unsigned long flags, int pc);
 
+struct ring_buffer_event *
+trace_current_buffer_lock_reserve(unsigned char type, unsigned long len,
+                                 unsigned long flags, int pc);
+void trace_current_buffer_unlock_commit(struct ring_buffer_event *event,
+                                       unsigned long flags, int pc);
+
 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
                                                struct trace_array_cpu *data);
 
@@ -426,6 +479,9 @@ void tracing_generic_entry_update(struct trace_entry *entry,
                                  unsigned long flags,
                                  int pc);
 
+void default_wait_pipe(struct trace_iterator *iter);
+void poll_wait_pipe(struct trace_iterator *iter);
+
 void ftrace(struct trace_array *tr,
                            struct trace_array_cpu *data,
                            unsigned long ip,
@@ -491,7 +547,7 @@ struct tracer_switch_ops {
 };
 #endif /* CONFIG_CONTEXT_SWITCH_TRACER */
 
-extern char *trace_find_cmdline(int pid);
+extern void trace_find_cmdline(int pid, char comm[]);
 
 #ifdef CONFIG_DYNAMIC_FTRACE
 extern unsigned long ftrace_update_tot_cnt;
@@ -525,6 +581,8 @@ extern int trace_selftest_startup_branch(struct tracer *trace,
 extern void *head_page(struct trace_array_cpu *data);
 extern long ns2usecs(cycle_t nsec);
 extern int
+trace_vbprintk(unsigned long ip, int depth, const char *fmt, va_list args);
+extern int
 trace_vprintk(unsigned long ip, int depth, const char *fmt, va_list args);
 
 extern unsigned long trace_flags;
@@ -607,7 +665,9 @@ enum trace_iterator_flags {
        TRACE_ITER_USERSTACKTRACE       = 0x4000,
        TRACE_ITER_SYM_USEROBJ          = 0x8000,
        TRACE_ITER_PRINTK_MSGONLY       = 0x10000,
-       TRACE_ITER_CONTEXT_INFO         = 0x20000 /* Print pid/cpu/time */
+       TRACE_ITER_CONTEXT_INFO         = 0x20000, /* Print pid/cpu/time */
+       TRACE_ITER_LATENCY_FMT          = 0x40000,
+       TRACE_ITER_GLOBAL_CLK           = 0x80000,
 };
 
 /*
@@ -691,4 +751,51 @@ static inline void trace_branch_disable(void)
 }
 #endif /* CONFIG_BRANCH_TRACER */
 
+/* set ring buffers to default size if not already done so */
+int tracing_update_buffers(void);
+
+/* trace event type bit fields, not numeric */
+enum {
+       TRACE_EVENT_TYPE_PRINTF         = 1,
+       TRACE_EVENT_TYPE_RAW            = 2,
+};
+
+struct ftrace_event_call {
+       char            *name;
+       char            *system;
+       struct dentry   *dir;
+       int             enabled;
+       int             (*regfunc)(void);
+       void            (*unregfunc)(void);
+       int             id;
+       int             (*raw_init)(void);
+       int             (*show_format)(struct trace_seq *s);
+};
+
+void event_trace_printk(unsigned long ip, const char *fmt, ...);
+extern struct ftrace_event_call __start_ftrace_events[];
+extern struct ftrace_event_call __stop_ftrace_events[];
+
+extern const char *__start___trace_bprintk_fmt[];
+extern const char *__stop___trace_bprintk_fmt[];
+
+/*
+ * The double __builtin_constant_p is because gcc will give us an error
+ * if we try to allocate the static variable to fmt if it is not a
+ * constant. Even with the outer if statement optimizing out.
+ */
+#define event_trace_printk(ip, fmt, args...)                           \
+do {                                                                   \
+       __trace_printk_check_format(fmt, ##args);                       \
+       tracing_record_cmdline(current);                                \
+       if (__builtin_constant_p(fmt)) {                                \
+               static const char *trace_printk_fmt                     \
+                 __attribute__((section("__trace_printk_fmt"))) =      \
+                       __builtin_constant_p(fmt) ? fmt : NULL;         \
+                                                                       \
+               __trace_bprintk(ip, trace_printk_fmt, ##args);          \
+       } else                                                          \
+               __trace_printk(ip, fmt, ##args);                        \
+} while (0)
+
 #endif /* _LINUX_KERNEL_TRACE_H */