NAME

libtracecmd - trace-cmd library APIs

SYNOPSIS

#include <trace-cmd.h>
Open and close trace file:


        struct tracecmd_input *tracecmd_open(const char *file, int flags);


        struct tracecmd_input *tracecmd_open_fd(int fd, int flags);


        struct tracecmd_input *tracecmd_open_head(const char *file, int flags);


        void tracecmd_close(struct tracecmd_input *handle);


        void tracecmd_set_private(struct tracecmd_input *handle, void *data);


        void *tracecmd_get_private(struct tracecmd_input *handle);
Read tracing records from a trace file:


        int tracecmd_init_data(struct tracecmd_input *handle);


        struct tep_record *tracecmd_read_cpu_first(struct tracecmd_input *handle, int cpu);


        struct tep_record *tracecmd_read_data(struct tracecmd_input *handle, int cpu);


        struct tep_record *tracecmd_read_at(struct tracecmd_input *handle, unsigned long long offset, int *cpu);


        void tracecmd_free_record(struct tep_record *record);


        struct tep_handle *tracecmd_get_tep(struct tracecmd_input *handle);
Iterating over events in a trace file:


        int tracecmd_iterate_events(struct tracecmd_input *handle,


                                    cpu_set_t *cpus, int cpu_size,


                                    int (*callback)(struct tracecmd_input *,


                                                    struct tep_record *,


                                                    int, void *),


                                    void *callback_data);


        int tracecmd_iterate_events_multi(struct tracecmd_input **handles,


                                          int nr_handles,


                                          int (*callback)(struct tracecmd_input *,


                                                                   struct tep_record *,


                                                           int, void *),


                                          void *callback_data);


        int tracecmd_iterate_events_reverse(struct tracecmd_input *handle,


                                    cpu_set_t *cpus, int cpu_size,


                                    int (*callback)(struct tracecmd_input *,


                                                    struct tep_record *,


                                                    int, void *),


                                    void *callback_data, bool cont);


        int tracecmd_follow_event(struct tracecmd_input *handle,


                                  const char *system, const char *event_name,


                                  int (*callback)(struct tracecmd_input *,


                                                  struct tep_event *,


                                                  struct tep_record *,


                                                  int, void *),


                                  void *callback_data);


        int tracecmd_follow_missed_events(struct tracecmd_input *handle,


                                           int (*callback)(struct tracecmd_input *,


                                                           struct tep_event *,


                                                           struct tep_record *,


                                                           int, void *),


                                           void *callback_data);


        struct tracecmd_filter *tracecmd_filter_add(struct tracecmd_input handle,


                                                    const char *filter_str, bool neg);


        int *tracecmd_iterate_reset(struct tracecmd_input *handle);
Read tracing instances from a trace file:


        int tracecmd_buffer_instances(struct tracecmd_input *handle);


        const char *tracecmd_buffer_instance_name(struct tracecmd_input *handle, int indx);


        struct tracecmd_input *tracecmd_buffer_instance_handle(struct tracecmd_input *handle, int indx);
Handle time stamps from a trace file:


        unsigned long long tracecmd_get_first_ts(struct tracecmd_input *handle);


        void tracecmd_add_ts_offset(struct tracecmd_input *handle, long long offset);


        int tracecmd_get_tsc2nsec(struct tracecmd_input *handle, int *mult, int pass[]shift, unsigned long long *offset);
Get traceing peer information from a trace file:


        unsigned long long *tracecmd_get_traceid(struct tracecmd_input *handle);


        int tracecmd_get_guest_cpumap(struct tracecmd_input *handle, unsigned long long trace_id, const char **name, int *vcpu_count, const int **cpu_pid);
Mapping host and guest trace files:


        int tracecmd_map_vcpus(struct tracecmd_input **handles, int nr_handles);


        struct tracecmd_cpu_map *tracecmd_get_cpu_map(struct tracecmd_input *handle, int cpu);


        struct tracecmd_cpu_map *tracecmd_map_find_by_host_pid(struct tracecmd_input *handle,


                                                      int host_pid);


        int tracecmd_map_get_host_pid(struct tracecmd_cpu_map *map);


        struct tracecmd_input *tracecmd_map_get_guest(struct tracecmd_cpu_map *map);


        void tracecmd_map_set_private(struct tracecmd_cpu_map *map, void *priv);


        void *tracecmd_map_get_private(struct tracecmd_cpu_map *map);
Control library logs:


        int tracecmd_set_loglevel(enum tep_loglevel level);

DESCRIPTION

The libtracecmd(3) library provides APIs to read, parse and write trace-cmd.dat(5) files, recorded with trace-cmd(1) application and containing tracing information from ftrace, the official Linux kernel tracer.

FILES

trace-cmd.h


        Header file to include in order to have access to the library APIs.
-ltracecmd


        Linker switch to add when building a program that uses the library.

SEE ALSO

libtraceevent(3) libtracefs(3) trace-cmd(1) trace-cmd.dat(5)

AUTHOR

Steven Rostedt <rostedt@goodmis.org[1]>
Tzvetomir Stoyanov <tz.stoyanov@gmail.com[2]>

REPORTING BUGS

Report bugs to <linux-trace-devel@vger.kernel.org[3]>

LICENSE

libtracecmd is Free Software licensed under the GNU LGPL 2.1

RESOURCES

https://git.kernel.org/pub/scm/utils/trace-cmd/trace-cmd.git/

COPYING

Copyright (C) 2020 VMware, Inc. Free use of this software is granted under the terms of the GNU Public License (GPL).

NOTES

1.

rostedt@goodmis.org

2.

tz.stoyanov@gmail.com

3.

linux-trace-devel@vger.kernel.org