15 files changed, 206 insertions, 181 deletions

diff --git a/tools/perf/Makefile b/tools/perf/Makefile
index e2ee3b589af7..406999668cab 100644
--- a/tools/perf/Makefile
+++ b/tools/perf/Makefile
@@ -356,7 +356,9 @@ LIB_H += util/parse-options.h
 LIB_H += util/parse-events.h
 LIB_H += util/quote.h
 LIB_H += util/util.h
+LIB_H += util/header.h
 LIB_H += util/help.h
+LIB_H += util/session.h
 LIB_H += util/strbuf.h
 LIB_H += util/string.h
 LIB_H += util/strlist.h
@@ -405,6 +407,7 @@ LIB_OBJS += util/callchain.o
 LIB_OBJS += util/values.o
 LIB_OBJS += util/debug.o
 LIB_OBJS += util/map.o
+LIB_OBJS += util/session.o
 LIB_OBJS += util/thread.o
 LIB_OBJS += util/trace-event-parse.o
 LIB_OBJS += util/trace-event-read.o
diff --git a/tools/perf/builtin-annotate.c b/tools/perf/builtin-annotate.c
index 0bf2e8f9af57..21a78d30d53d 100644
--- a/tools/perf/builtin-annotate.c
+++ b/tools/perf/builtin-annotate.c
@@ -25,6 +25,7 @@
 #include "util/thread.h"
 #include "util/sort.h"
 #include "util/hist.h"
+#include "util/session.h"
 #include "util/data_map.h"
 
 static char             const *input_name = "perf.data";
@@ -462,21 +463,23 @@ static struct perf_file_handler file_handler = {
 
 static int __cmd_annotate(void)
 {
-        struct perf_header *header;
+        struct perf_session *session = perf_session__new(input_name, O_RDONLY, force);
         struct thread *idle;
         int ret;
 
+        if (session == NULL)
+                return -ENOMEM;
+
         idle = register_idle_thread();
         register_perf_file_handler(&file_handler);
 
-        ret = mmap_dispatch_perf_file(&header, input_name, 0, 0,
-                                      &event__cwdlen, &event__cwd);
+        ret = perf_session__process_events(session, 0, &event__cwdlen, &event__cwd);
         if (ret)
-                return ret;
+                goto out_delete;
 
         if (dump_trace) {
                 event__print_totals();
-                return 0;
+                goto out_delete;
         }
 
         if (verbose > 3)
@@ -489,6 +492,8 @@ static int __cmd_annotate(void)
         output__resort(event__total[0]);
 
         find_annotations();
+out_delete:
+        perf_session__delete(session);
 
         return ret;
 }
diff --git a/tools/perf/builtin-buildid-list.c b/tools/perf/builtin-buildid-list.c
index dcb6143a0002..bfd16a1594e4 100644
--- a/tools/perf/builtin-buildid-list.c
+++ b/tools/perf/builtin-buildid-list.c
@@ -11,8 +11,8 @@
 #include "util/cache.h"
 #include "util/data_map.h"
 #include "util/debug.h"
-#include "util/header.h"
 #include "util/parse-options.h"
+#include "util/session.h"
 #include "util/symbol.h"
 
 static char const *input_name = "perf.data";
@@ -55,56 +55,17 @@ static int perf_file_section__process_buildids(struct perf_file_section *self,
 static int __cmd_buildid_list(void)
 {
         int err = -1;
-        struct perf_header *header;
-        struct perf_file_header f_header;
-        struct stat input_stat;
-        int input = open(input_name, O_RDONLY);
+        struct perf_session *session = perf_session__new(input_name, O_RDONLY, force);
 
-        if (input < 0) {
-                pr_err("failed to open file: %s", input_name);
-                if (!strcmp(input_name, "perf.data"))
-                        pr_err("  (try 'perf record' first)");
-                pr_err("\n");
-                goto out;
-        }
-
-        err = fstat(input, &input_stat);
-        if (err < 0) {
-                perror("failed to stat file");
-                goto out_close;
-        }
-
-        if (!force && input_stat.st_uid && (input_stat.st_uid != geteuid())) {
-                pr_err("file %s not owned by current user or root\n",
-                       input_name);
-                goto out_close;
-        }
-
-        if (!input_stat.st_size) {
-                pr_info("zero-sized file, nothing to do!\n");
-                goto out_close;
-        }
-
-        err = -1;
-        header = perf_header__new();
-        if (header == NULL)
-                goto out_close;
-
-        if (perf_file_header__read(&f_header, header, input) < 0) {
-                pr_warning("incompatible file format");
-                goto out_close;
-        }
+        if (session == NULL)
+                return -1;
 
-        err = perf_header__process_sections(header, input,
+        err = perf_header__process_sections(&session->header, session->fd,
                                          perf_file_section__process_buildids);
+        if (err >= 0)
+                dsos__fprintf_buildid(stdout);
 
-        if (err < 0)
-                goto out_close;
-
-        dsos__fprintf_buildid(stdout);
-out_close:
-        close(input);
-out:
+        perf_session__delete(session);
         return err;
 }
 
diff --git a/tools/perf/builtin-kmem.c b/tools/perf/builtin-kmem.c
index fe73435192b3..2071d2485913 100644
--- a/tools/perf/builtin-kmem.c
+++ b/tools/perf/builtin-kmem.c
@@ -6,6 +6,7 @@
 #include "util/symbol.h"
 #include "util/thread.h"
 #include "util/header.h"
+#include "util/session.h"
 
 #include "util/parse-options.h"
 #include "util/trace-event.h"
@@ -20,7 +21,6 @@ typedef int (*sort_fn_t)(struct alloc_stat *, struct alloc_stat *);
 
 static char const               *input_name = "perf.data";
 
-static struct perf_header       *header;
 static u64                      sample_type;
 
 static int                      alloc_flag;
@@ -367,11 +367,18 @@ static struct perf_file_handler file_handler = {
 
 static int read_events(void)
 {
+        int err;
+        struct perf_session *session = perf_session__new(input_name, O_RDONLY, 0);
+
+        if (session == NULL)
+                return -ENOMEM;
+
         register_idle_thread();
         register_perf_file_handler(&file_handler);
 
-        return mmap_dispatch_perf_file(&header, input_name, 0, 0,
-                                       &event__cwdlen, &event__cwd);
+        err = perf_session__process_events(session, 0, &event__cwdlen, &event__cwd);
+        perf_session__delete(session);
+        return err;
 }
 
 static double fragmentation(unsigned long n_req, unsigned long n_alloc)
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 0e519c667e3a..4decbd14eaed 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -17,6 +17,7 @@
 #include "util/header.h"
 #include "util/event.h"
 #include "util/debug.h"
+#include "util/session.h"
 #include "util/symbol.h"
 
 #include <unistd.h>
@@ -62,7 +63,7 @@ static int			nr_cpu				=      0;
 
 static int                      file_new                        =      1;
 
-struct perf_header              *header                         =   NULL;
+static struct perf_session      *session;
 
 struct mmap_data {
         int                     counter;
@@ -216,12 +217,12 @@ static struct perf_header_attr *get_header_attr(struct perf_event_attr *a, int n
 {
         struct perf_header_attr *h_attr;
 
-        if (nr < header->attrs) {
-                h_attr = header->attr[nr];
+        if (nr < session->header.attrs) {
+                h_attr = session->header.attr[nr];
         } else {
                 h_attr = perf_header_attr__new(a);
                 if (h_attr != NULL)
-                        if (perf_header__add_attr(header, h_attr) < 0) {
+                        if (perf_header__add_attr(&session->header, h_attr) < 0) {
                                 perf_header_attr__delete(h_attr);
                                 h_attr = NULL;
                         }
@@ -395,9 +396,9 @@ static void open_counters(int cpu, pid_t pid)
 
 static void atexit_header(void)
 {
-        header->data_size += bytes_written;
+        session->header.data_size += bytes_written;
 
-        perf_header__write(header, output, true);
+        perf_header__write(&session->header, output, true);
 }
 
 static int __cmd_record(int argc, const char **argv)
@@ -440,24 +441,24 @@ static int __cmd_record(int argc, const char **argv)
                 exit(-1);
         }
 
-        header = perf_header__new();
-        if (header == NULL) {
+        session = perf_session__new(output_name, O_WRONLY, force);
+        if (session == NULL) {
                 pr_err("Not enough memory for reading perf file header\n");
                 return -1;
         }
 
         if (!file_new) {
-                err = perf_header__read(header, output);
+                err = perf_header__read(&session->header, output);
                 if (err < 0)
                         return err;
         }
 
         if (raw_samples) {
-                perf_header__set_feat(header, HEADER_TRACE_INFO);
+                perf_header__set_feat(&session->header, HEADER_TRACE_INFO);
         } else {
                 for (i = 0; i < nr_counters; i++) {
                         if (attrs[i].sample_type & PERF_SAMPLE_RAW) {
-                                perf_header__set_feat(header, HEADER_TRACE_INFO);
+                                perf_header__set_feat(&session->header, HEADER_TRACE_INFO);
                                 break;
                         }
                 }
@@ -481,7 +482,7 @@ static int __cmd_record(int argc, const char **argv)
         }
 
         if (file_new) {
-                err = perf_header__write(header, output, false);
+                err = perf_header__write(&session->header, output, false);
                 if (err < 0)
                         return err;
         }
diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index 2b9eb3a553ed..e2ec49a9b731 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -22,6 +22,7 @@
 #include "perf.h"
 #include "util/debug.h"
 #include "util/header.h"
+#include "util/session.h"
 
 #include "util/parse-options.h"
 #include "util/parse-events.h"
@@ -52,7 +53,7 @@ static int		exclude_other = 1;
 
 static char             callchain_default_opt[] = "fractal,0.5";
 
-static struct perf_header *header;
+static struct perf_session *session;
 
 static u64              sample_type;
 
@@ -701,7 +702,7 @@ static int process_read_event(event_t *event)
 {
         struct perf_event_attr *attr;
 
-        attr = perf_header__find_attr(event->read.id, header);
+        attr = perf_header__find_attr(event->read.id, &session->header);
 
         if (show_threads) {
                 const char *name = attr ? __event_name(attr->type, attr->config)
@@ -766,6 +767,10 @@ static int __cmd_report(void)
         struct thread *idle;
         int ret;
 
+        session = perf_session__new(input_name, O_RDONLY, force);
+        if (session == NULL)
+                return -ENOMEM;
+
         idle = register_idle_thread();
         thread__comm_adjust(idle);
 
@@ -774,14 +779,14 @@ static int __cmd_report(void)
 
         register_perf_file_handler(&file_handler);
 
-        ret = mmap_dispatch_perf_file(&header, input_name, force,
-                                      full_paths, &event__cwdlen, &event__cwd);
+        ret = perf_session__process_events(session, full_paths,
+                                           &event__cwdlen, &event__cwd);
         if (ret)
-                return ret;
+                goto out_delete;
 
         if (dump_trace) {
                 event__print_totals();
-                return 0;
+                goto out_delete;
         }
 
         if (verbose > 3)
@@ -796,7 +801,8 @@ static int __cmd_report(void)
 
         if (show_threads)
                 perf_read_values_destroy(&show_threads_values);
-
+out_delete:
+        perf_session__delete(session);
         return ret;
 }
 
diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
index 7cca7c15b40a..65021fe1361e 100644
--- a/tools/perf/builtin-sched.c
+++ b/tools/perf/builtin-sched.c
@@ -6,6 +6,7 @@
 #include "util/symbol.h"
 #include "util/thread.h"
 #include "util/header.h"
+#include "util/session.h"
 
 #include "util/parse-options.h"
 #include "util/trace-event.h"
@@ -21,7 +22,6 @@
 
 static char                     const *input_name = "perf.data";
 
-static struct perf_header       *header;
 static u64                      sample_type;
 
 static char                     default_sort_order[] = "avg, max, switch, runtime";
@@ -1663,11 +1663,18 @@ static struct perf_file_handler file_handler = {
 
 static int read_events(void)
 {
+        int err;
+        struct perf_session *session = perf_session__new(input_name, O_RDONLY, 0);
+
+        if (session == NULL)
+                return -ENOMEM;
+
         register_idle_thread();
         register_perf_file_handler(&file_handler);
 
-        return mmap_dispatch_perf_file(&header, input_name, 0, 0,
-                                       &event__cwdlen, &event__cwd);
+        err = perf_session__process_events(session, 0, &event__cwdlen, &event__cwd);
+        perf_session__delete(session);
+        return err;
 }
 
 static void print_bad_events(void)
diff --git a/tools/perf/builtin-timechart.c b/tools/perf/builtin-timechart.c
index f472df9561ee..759dd2b35fdb 100644
--- a/tools/perf/builtin-timechart.c
+++ b/tools/perf/builtin-timechart.c
@@ -1059,15 +1059,17 @@ static struct perf_file_handler file_handler = {
 
 static int __cmd_timechart(void)
 {
-        struct perf_header *header;
+        struct perf_session *session = perf_session__new(input_name, O_RDONLY, 0);
         int ret;
 
+        if (session == NULL)
+                return -ENOMEM;
+
         register_perf_file_handler(&file_handler);
 
-        ret = mmap_dispatch_perf_file(&header, input_name, 0, 0,
-                                      &event__cwdlen, &event__cwd);
+        ret = perf_session__process_events(session, 0, &event__cwdlen, &event__cwd);
         if (ret)
-                return EXIT_FAILURE;
+                goto out_delete;
 
         process_samples();
 
@@ -1079,8 +1081,9 @@ static int __cmd_timechart(void)
 
         pr_info("Written %2.1f seconds of trace to %s.\n",
                 (last_time - first_time) / 1000000000.0, output_name);
-
-        return EXIT_SUCCESS;
+out_delete:
+        perf_session__delete(session);
+        return ret;
 }
 
 static const char * const timechart_usage[] = {
diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index c2fcc34486f5..0756664666f1 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -7,6 +7,7 @@
 #include "util/header.h"
 #include "util/exec_cmd.h"
 #include "util/trace-event.h"
+#include "util/session.h"
 
 static char const               *script_name;
 static char const               *generate_script_lang;
@@ -61,7 +62,7 @@ static int cleanup_scripting(void)
 
 static char const               *input_name = "perf.data";
 
-static struct perf_header       *header;
+static struct perf_session      *session;
 static u64                      sample_type;
 
 static int process_sample_event(event_t *event)
@@ -126,11 +127,18 @@ static struct perf_file_handler file_handler = {
 
 static int __cmd_trace(void)
 {
+        int err;
+
+        session = perf_session__new(input_name, O_RDONLY, 0);
+        if (session == NULL)
+                return -ENOMEM;
+
         register_idle_thread();
         register_perf_file_handler(&file_handler);
 
-        return mmap_dispatch_perf_file(&header, input_name,
-                                       0, 0, &event__cwdlen, &event__cwd);
+        err = perf_session__process_events(session, 0, &event__cwdlen, &event__cwd);
+        perf_session__delete(session);
+        return err;
 }
 
 struct script_spec {
@@ -348,11 +356,7 @@ int cmd_trace(int argc, const char **argv, const char *prefix __used)
                         return -1;
                 }
 
-                header = perf_header__new();
-                if (header == NULL)
-                        return -1;
-
-                perf_header__read(header, input);
+                perf_header__read(&session->header, input);
                 err = scripting_ops->generate_script("perf-trace");
                 goto out;
         }
diff --git a/tools/perf/util/data_map.c b/tools/perf/util/data_map.c
index 59b65d0bd7c1..6d46dda53a29 100644
--- a/tools/perf/util/data_map.c
+++ b/tools/perf/util/data_map.c
@@ -129,23 +129,16 @@ out:
         return err;
 }
 
-int mmap_dispatch_perf_file(struct perf_header **pheader,
-                            const char *input_name,
-                            int force,
-                            int full_paths,
-                            int *cwdlen,
-                            char **cwd)
+int perf_session__process_events(struct perf_session *self,
+                                 int full_paths, int *cwdlen, char **cwd)
 {
         int err;
-        struct perf_header *header;
         unsigned long head, shift;
         unsigned long offset = 0;
-        struct stat input_stat;
         size_t  page_size;
         u64 sample_type;
         event_t *event;
         uint32_t size;
-        int input;
         char *buf;
 
         if (curr_handler == NULL) {
@@ -155,56 +148,19 @@ int mmap_dispatch_perf_file(struct perf_header **pheader,
 
         page_size = getpagesize();
 
-        input = open(input_name, O_RDONLY);
-        if (input < 0) {
-                pr_err("Failed to open file: %s", input_name);
-                if (!strcmp(input_name, "perf.data"))
-                        pr_err("  (try 'perf record' first)");
-                pr_err("\n");
-                return -errno;
-        }
-
-        if (fstat(input, &input_stat) < 0) {
-                pr_err("failed to stat file");
-                err = -errno;
-                goto out_close;
-        }
-
-        err = -EACCES;
-        if (!force && input_stat.st_uid && (input_stat.st_uid != geteuid())) {
-                pr_err("file: %s not owned by current user or root\n",
-                        input_name);
-                goto out_close;
-        }
-
-        if (input_stat.st_size == 0) {
-                pr_info("zero-sized file, nothing to do!\n");
-                goto done;
-        }
-
-        err = -ENOMEM;
-        header = perf_header__new();
-        if (header == NULL)
-                goto out_close;
-
-        err = perf_header__read(header, input);
-        if (err < 0)
-                goto out_delete;
-        *pheader = header;
-        head = header->data_offset;
-
-        sample_type = perf_header__sample_type(header);
+        head = self->header.data_offset;
+        sample_type = perf_header__sample_type(&self->header);
 
         err = -EINVAL;
         if (curr_handler->sample_type_check &&
             curr_handler->sample_type_check(sample_type) < 0)
-                goto out_delete;
+                goto out_err;
 
         if (!full_paths) {
                 if (getcwd(__cwd, sizeof(__cwd)) == NULL) {
                         pr_err("failed to get the current directory\n");
                         err = -errno;
-                        goto out_delete;
+                        goto out_err;
                 }
                 *cwd = __cwd;
                 *cwdlen = strlen(*cwd);
@@ -219,11 +175,11 @@ int mmap_dispatch_perf_file(struct perf_header **pheader,
 
 remap:
         buf = mmap(NULL, page_size * mmap_window, PROT_READ,
-                   MAP_SHARED, input, offset);
+                   MAP_SHARED, self->fd, offset);
         if (buf == MAP_FAILED) {
                 pr_err("failed to mmap file\n");
                 err = -errno;
-                goto out_delete;
+                goto out_err;
         }
 
 more:
@@ -273,19 +229,14 @@ more:
 
         head += size;
 
-        if (offset + head >= header->data_offset + header->data_size)
+        if (offset + head >= self->header.data_offset + self->header.data_size)
                 goto done;
 
-        if (offset + head < (unsigned long)input_stat.st_size)
+        if (offset + head < self->size)
                 goto more;
 
 done:
         err = 0;
-out_close:
-        close(input);
-
+out_err:
         return err;
-out_delete:
-        perf_header__delete(header);
-        goto out_close;
 }
diff --git a/tools/perf/util/data_map.h b/tools/perf/util/data_map.h
index 258a87bcc4fb..98c5b823388c 100644
--- a/tools/perf/util/data_map.h
+++ b/tools/perf/util/data_map.h
@@ -3,6 +3,7 @@
 
 #include "event.h"
 #include "header.h"
+#include "session.h"
 
 typedef int (*event_type_handler_t)(event_t *);
 
@@ -21,12 +22,8 @@ struct perf_file_handler {
 };
 
 void register_perf_file_handler(struct perf_file_handler *handler);
-int mmap_dispatch_perf_file(struct perf_header **pheader,
-                            const char *input_name,
-                            int force,
-                            int full_paths,
-                            int *cwdlen,
-                            char **cwd);
+int perf_session__process_events(struct perf_session *self,
+                                 int full_paths, int *cwdlen, char **cwd);
 int perf_header__read_build_ids(int input, u64 offset, u64 file_size);
 
 #endif
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 59a9c0b3033e..f2e8d8715111 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -58,35 +58,19 @@ int perf_header_attr__add_id(struct perf_header_attr *self, u64 id)
         return 0;
 }
 
-/*
- * Create new perf.data header:
- */
-struct perf_header *perf_header__new(void)
+int perf_header__init(struct perf_header *self)
 {
-        struct perf_header *self = zalloc(sizeof(*self));
-
-        if (self != NULL) {
-                self->size = 1;
-                self->attr = malloc(sizeof(void *));
-
-                if (self->attr == NULL) {
-                        free(self);
-                        self = NULL;
-                }
-        }
-
-        return self;
+        self->size = 1;
+        self->attr = malloc(sizeof(void *));
+        return self->attr == NULL ? -ENOMEM : 0;
 }
 
-void perf_header__delete(struct perf_header *self)
+void perf_header__exit(struct perf_header *self)
 {
         int i;
-
         for (i = 0; i < self->attrs; ++i)
-                perf_header_attr__delete(self->attr[i]);
-
+                perf_header_attr__delete(self->attr[i]);
         free(self->attr);
-        free(self);
 }
 
 int perf_header__add_attr(struct perf_header *self,
diff --git a/tools/perf/util/header.h b/tools/perf/util/header.h
index d1dbe2b79c42..d118d05d3abe 100644
--- a/tools/perf/util/header.h
+++ b/tools/perf/util/header.h
@@ -55,8 +55,8 @@ struct perf_header {
         DECLARE_BITMAP(adds_features, HEADER_FEAT_BITS);
 };
 
-struct perf_header *perf_header__new(void);
-void perf_header__delete(struct perf_header *self);
+int perf_header__init(struct perf_header *self);
+void perf_header__exit(struct perf_header *self);
 
 int perf_header__read(struct perf_header *self, int fd);
 int perf_header__write(struct perf_header *self, int fd, bool at_exit);
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
new file mode 100644
index 000000000000..707ce1cb1621
--- /dev/null
+++ b/tools/perf/util/session.c
@@ -0,0 +1,80 @@
+#include <linux/kernel.h>
+
+#include <unistd.h>
+#include <sys/types.h>
+
+#include "session.h"
+#include "util.h"
+
+static int perf_session__open(struct perf_session *self, bool force)
+{
+        struct stat input_stat;
+
+        self->fd = open(self->filename, O_RDONLY);
+        if (self->fd < 0) {
+                pr_err("failed to open file: %s", self->filename);
+                if (!strcmp(self->filename, "perf.data"))
+                        pr_err("  (try 'perf record' first)");
+                pr_err("\n");
+                return -errno;
+        }
+
+        if (fstat(self->fd, &input_stat) < 0)
+                goto out_close;
+
+        if (!force && input_stat.st_uid && (input_stat.st_uid != geteuid())) {
+                pr_err("file %s not owned by current user or root\n",
+                       self->filename);
+                goto out_close;
+        }
+
+        if (!input_stat.st_size) {
+                pr_info("zero-sized file (%s), nothing to do!\n",
+                        self->filename);
+                goto out_close;
+        }
+
+        if (perf_header__read(&self->header, self->fd) < 0) {
+                pr_err("incompatible file format");
+                goto out_close;
+        }
+
+        self->size = input_stat.st_size;
+        return 0;
+
+out_close:
+        close(self->fd);
+        self->fd = -1;
+        return -1;
+}
+
+struct perf_session *perf_session__new(const char *filename, int mode, bool force)
+{
+        size_t len = strlen(filename) + 1;
+        struct perf_session *self = zalloc(sizeof(*self) + len);
+
+        if (self == NULL)
+                goto out;
+
+        if (perf_header__init(&self->header) < 0)
+                goto out_delete;
+
+        memcpy(self->filename, filename, len);
+
+        if (mode == O_RDONLY && perf_session__open(self, force) < 0) {
+                perf_session__delete(self);
+                self = NULL;
+        }
+out:
+        return self;
+out_delete:
+        free(self);
+        return NULL;
+}
+
+void perf_session__delete(struct perf_session *self)
+{
+        perf_header__exit(&self->header);
+        close(self->fd);
+        free(self);
+}
diff --git a/tools/perf/util/session.h b/tools/perf/util/session.h
new file mode 100644
index 000000000000..f3699c8c8ed4
--- /dev/null
+++ b/tools/perf/util/session.h
@@ -0,0 +1,16 @@
+#ifndef __PERF_SESSION_H
+#define __PERF_SESSION_H
+
+#include "header.h"
+
+struct perf_session {
+        struct perf_header      header;
+        unsigned long           size;
+        int                     fd;
+        char filename[0];
+};
+
+struct perf_session *perf_session__new(const char *filename, int mode, bool force);
+void perf_session__delete(struct perf_session *self);
+
+#endif /* __PERF_SESSION_H */