6 files changed, 334 insertions, 401 deletions

diff --git a/tools/perf/Makefile b/tools/perf/Makefile
index 5a429966c995..495eb6d97fa0 100644
--- a/tools/perf/Makefile
+++ b/tools/perf/Makefile
@@ -342,6 +342,7 @@ LIB_H += util/values.h
 LIB_H += util/sort.h
 LIB_H += util/hist.h
 LIB_H += util/thread.h
+LIB_H += util/data_map.h
 
 LIB_OBJS += util/abspath.o
 LIB_OBJS += util/alias.o
@@ -378,6 +379,7 @@ LIB_OBJS += util/trace-event-info.o
 LIB_OBJS += util/svghelper.o
 LIB_OBJS += util/sort.o
 LIB_OBJS += util/hist.o
+LIB_OBJS += util/data_map.o
 
 BUILTIN_OBJS += builtin-annotate.o
 BUILTIN_OBJS += builtin-help.o
diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index 12f8c868fcd7..87c4582303bf 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -26,6 +26,7 @@
 #include "util/parse-options.h"
 #include "util/parse-events.h"
 
+#include "util/data_map.h"
 #include "util/thread.h"
 #include "util/sort.h"
 #include "util/hist.h"
@@ -37,7 +38,6 @@ static char		*dso_list_str, *comm_list_str, *sym_list_str,
 static struct strlist   *dso_list, *comm_list, *sym_list;
 
 static int              force;
-static int              input;
 
 static int              full_paths;
 static int              show_nr_samples;
@@ -48,15 +48,11 @@ static struct perf_read_values	show_threads_values;
 static char             default_pretty_printing_style[] = "normal";
 static char             *pretty_printing_style = default_pretty_printing_style;
 
-static unsigned long    page_size;
-static unsigned long    mmap_window = 32;
-
 static int              exclude_other = 1;
 
 static char             callchain_default_opt[] = "fractal,0.5";
 
-static char             __cwd[PATH_MAX];
-static char             *cwd = __cwd;
+static char             *cwd;
 static int              cwdlen;
 
 static struct rb_root   threads;
@@ -815,208 +811,71 @@ process_read_event(event_t *event, unsigned long offset, unsigned long head)
         return 0;
 }
 
-static int
-process_event(event_t *event, unsigned long offset, unsigned long head)
-{
-        trace_event(event);
-
-        switch (event->header.type) {
-        case PERF_RECORD_SAMPLE:
-                return process_sample_event(event, offset, head);
-
-        case PERF_RECORD_MMAP:
-                return process_mmap_event(event, offset, head);
-
-        case PERF_RECORD_COMM:
-                return process_comm_event(event, offset, head);
-
-        case PERF_RECORD_FORK:
-        case PERF_RECORD_EXIT:
-                return process_task_event(event, offset, head);
-
-        case PERF_RECORD_LOST:
-                return process_lost_event(event, offset, head);
-
-        case PERF_RECORD_READ:
-                return process_read_event(event, offset, head);
-
-        /*
-         * We dont process them right now but they are fine:
-         */
-
-        case PERF_RECORD_THROTTLE:
-        case PERF_RECORD_UNTHROTTLE:
-                return 0;
-
-        default:
-                return -1;
-        }
-
-        return 0;
-}
-
-static int __cmd_report(void)
+static int sample_type_check(u64 type)
 {
-        int ret, rc = EXIT_FAILURE;
-        unsigned long offset = 0;
-        unsigned long head, shift;
-        struct stat input_stat;
-        struct thread *idle;
-        event_t *event;
-        uint32_t size;
-        char *buf;
-
-        idle = register_idle_thread(&threads, &last_match);
-        thread__comm_adjust(idle);
-
-        if (show_threads)
-                perf_read_values_init(&show_threads_values);
-
-        input = open(input_name, O_RDONLY);
-        if (input < 0) {
-                fprintf(stderr, " failed to open file: %s", input_name);
-                if (!strcmp(input_name, "perf.data"))
-                        fprintf(stderr, "  (try 'perf record' first)");
-                fprintf(stderr, "\n");
-                exit(-1);
-        }
-
-        ret = fstat(input, &input_stat);
-        if (ret < 0) {
-                perror("failed to stat file");
-                exit(-1);
-        }
-
-        if (!force && input_stat.st_uid && (input_stat.st_uid != geteuid())) {
-                fprintf(stderr, "file: %s not owned by current user or root\n", input_name);
-                exit(-1);
-        }
-
-        if (!input_stat.st_size) {
-                fprintf(stderr, "zero-sized file, nothing to do!\n");
-                exit(0);
-        }
-
-        header = perf_header__read(input);
-        head = header->data_offset;
-
-        sample_type = perf_header__sample_type(header);
+        sample_type = type;
 
         if (!(sample_type & PERF_SAMPLE_CALLCHAIN)) {
                 if (sort__has_parent) {
                         fprintf(stderr, "selected --sort parent, but no"
                                         " callchain data. Did you call"
                                         " perf record without -g?\n");
-                        exit(-1);
+                        return -1;
                 }
                 if (callchain) {
                         fprintf(stderr, "selected -g but no callchain data."
                                         " Did you call perf record without"
                                         " -g?\n");
-                        exit(-1);
+                        return -1;
                 }
         } else if (callchain_param.mode != CHAIN_NONE && !callchain) {
                         callchain = 1;
                         if (register_callchain_param(&callchain_param) < 0) {
                                 fprintf(stderr, "Can't register callchain"
                                                 " params\n");
-                                exit(-1);
+                                return -1;
                         }
         }
 
-        if (load_kernel() < 0) {
-                perror("failed to load kernel symbols");
-                return EXIT_FAILURE;
-        }
-
-        if (!full_paths) {
-                if (getcwd(__cwd, sizeof(__cwd)) == NULL) {
-                        perror("failed to get the current directory");
-                        return EXIT_FAILURE;
-                }
-                cwdlen = strlen(cwd);
-        } else {
-                cwd = NULL;
-                cwdlen = 0;
-        }
-
-        shift = page_size * (head / page_size);
-        offset += shift;
-        head -= shift;
-
-remap:
-        buf = (char *)mmap(NULL, page_size * mmap_window, PROT_READ,
-                           MAP_SHARED, input, offset);
-        if (buf == MAP_FAILED) {
-                perror("failed to mmap file");
-                exit(-1);
-        }
-
-more:
-        event = (event_t *)(buf + head);
-
-        size = event->header.size;
-        if (!size)
-                size = 8;
-
-        if (head + event->header.size >= page_size * mmap_window) {
-                int munmap_ret;
-
-                shift = page_size * (head / page_size);
-
-                munmap_ret = munmap(buf, page_size * mmap_window);
-                assert(munmap_ret == 0);
-
-                offset += shift;
-                head -= shift;
-                goto remap;
-        }
-
-        size = event->header.size;
-
-        dump_printf("\n%p [%p]: event: %d\n",
-                        (void *)(offset + head),
-                        (void *)(long)event->header.size,
-                        event->header.type);
-
-        if (!size || process_event(event, offset, head) < 0) {
-
-                dump_printf("%p [%p]: skipping unknown header type: %d\n",
-                        (void *)(offset + head),
-                        (void *)(long)(event->header.size),
-                        event->header.type);
-
-                total_unknown++;
+        return 0;
+}
 
-                /*
-                 * assume we lost track of the stream, check alignment, and
-                 * increment a single u64 in the hope to catch on again 'soon'.
-                 */
+static struct perf_file_handler file_handler = {
+        .process_sample_event   = process_sample_event,
+        .process_mmap_event     = process_mmap_event,
+        .process_comm_event     = process_comm_event,
+        .process_exit_event     = process_task_event,
+        .process_fork_event     = process_task_event,
+        .process_lost_event     = process_lost_event,
+        .process_read_event     = process_read_event,
+        .sample_type_check      = sample_type_check,
+};
 
-                if (unlikely(head & 7))
-                        head &= ~7ULL;
 
-                size = 8;
-        }
+static int __cmd_report(void)
+{
+        struct thread *idle;
+        int ret;
 
-        head += size;
+        idle = register_idle_thread(&threads, &last_match);
+        thread__comm_adjust(idle);
 
-        if (offset + head >= header->data_offset + header->data_size)
-                goto done;
+        if (show_threads)
+                perf_read_values_init(&show_threads_values);
 
-        if (offset + head < (unsigned long)input_stat.st_size)
-                goto more;
+        register_perf_file_handler(&file_handler);
 
-done:
-        rc = EXIT_SUCCESS;
-        close(input);
+        ret = mmap_dispatch_perf_file(&header, input_name, force, full_paths,
+                                      &cwdlen, &cwd);
+        if (ret)
+                return ret;
 
         dump_printf("      IP events: %10ld\n", total);
         dump_printf("    mmap events: %10ld\n", total_mmap);
         dump_printf("    comm events: %10ld\n", total_comm);
         dump_printf("    fork events: %10ld\n", total_fork);
         dump_printf("    lost events: %10ld\n", total_lost);
-        dump_printf(" unknown events: %10ld\n", total_unknown);
+        dump_printf(" unknown events: %10ld\n", file_handler.total_unknown);
 
         if (dump_trace)
                 return 0;
@@ -1034,7 +893,7 @@ done:
         if (show_threads)
                 perf_read_values_destroy(&show_threads_values);
 
-        return rc;
+        return ret;
 }
 
 static int
@@ -1177,8 +1036,6 @@ int cmd_report(int argc, const char **argv, const char *prefix __used)
 {
         symbol__init();
 
-        page_size = getpagesize();
-
         argc = parse_options(argc, argv, options, report_usage, 0);
 
         setup_sorting();
diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
index 18871380b015..e1df7055ab82 100644
--- a/tools/perf/builtin-sched.c
+++ b/tools/perf/builtin-sched.c
@@ -11,6 +11,7 @@
 #include "util/trace-event.h"
 
 #include "util/debug.h"
+#include "util/data_map.h"
 
 #include <sys/types.h>
 #include <sys/prctl.h>
@@ -20,9 +21,6 @@
 #include <math.h>
 
 static char                     const *input_name = "perf.data";
-static int                      input;
-static unsigned long            page_size;
-static unsigned long            mmap_window = 32;
 
 static unsigned long            total_comm = 0;
 
@@ -35,6 +33,9 @@ static u64			sample_type;
 static char                     default_sort_order[] = "avg, max, switch, runtime";
 static char                     *sort_order = default_sort_order;
 
+static char                     *cwd;
+static int                      cwdlen;
+
 #define PR_SET_NAME             15               /* Set process name */
 #define MAX_CPUS                4096
 
@@ -1594,129 +1595,43 @@ process_sample_event(event_t *event, unsigned long offset, unsigned long head)
 }
 
 static int
-process_event(event_t *event, unsigned long offset, unsigned long head)
+process_lost_event(event_t *event __used,
+                   unsigned long offset __used,
+                   unsigned long head __used)
 {
-        trace_event(event);
-
-        nr_events++;
-        switch (event->header.type) {
-        case PERF_RECORD_MMAP:
-                return 0;
-        case PERF_RECORD_LOST:
-                nr_lost_chunks++;
-                nr_lost_events += event->lost.lost;
-                return 0;
-
-        case PERF_RECORD_COMM:
-                return process_comm_event(event, offset, head);
+        nr_lost_chunks++;
+        nr_lost_events += event->lost.lost;
 
-        case PERF_RECORD_EXIT ... PERF_RECORD_READ:
-                return 0;
+        return 0;
+}
 
-        case PERF_RECORD_SAMPLE:
-                return process_sample_event(event, offset, head);
+static int sample_type_check(u64 type)
+{
+        sample_type = type;
 
-        case PERF_RECORD_MAX:
-        default:
+        if (!(sample_type & PERF_SAMPLE_RAW)) {
+                fprintf(stderr,
+                        "No trace sample to read. Did you call perf record "
+                        "without -R?");
                 return -1;
         }
 
         return 0;
 }
 
+static struct perf_file_handler file_handler = {
+        .process_sample_event   = process_sample_event,
+        .process_comm_event     = process_comm_event,
+        .process_lost_event     = process_lost_event,
+        .sample_type_check      = sample_type_check,
+};
+
 static int read_events(void)
 {
-        int ret, rc = EXIT_FAILURE;
-        unsigned long offset = 0;
-        unsigned long head = 0;
-        struct stat perf_stat;
-        event_t *event;
-        uint32_t size;
-        char *buf;
-
         register_idle_thread(&threads, &last_match);
+        register_perf_file_handler(&file_handler);
 
-        input = open(input_name, O_RDONLY);
-        if (input < 0) {
-                perror("failed to open file");
-                exit(-1);
-        }
-
-        ret = fstat(input, &perf_stat);
-        if (ret < 0) {
-                perror("failed to stat file");
-                exit(-1);
-        }
-
-        if (!perf_stat.st_size) {
-                fprintf(stderr, "zero-sized file, nothing to do!\n");
-                exit(0);
-        }
-        header = perf_header__read(input);
-        head = header->data_offset;
-        sample_type = perf_header__sample_type(header);
-
-        if (!(sample_type & PERF_SAMPLE_RAW))
-                die("No trace sample to read. Did you call perf record "
-                    "without -R?");
-
-        if (load_kernel() < 0) {
-                perror("failed to load kernel symbols");
-                return EXIT_FAILURE;
-        }
-
-remap:
-        buf = (char *)mmap(NULL, page_size * mmap_window, PROT_READ,
-                           MAP_SHARED, input, offset);
-        if (buf == MAP_FAILED) {
-                perror("failed to mmap file");
-                exit(-1);
-        }
-
-more:
-        event = (event_t *)(buf + head);
-
-        size = event->header.size;
-        if (!size)
-                size = 8;
-
-        if (head + event->header.size >= page_size * mmap_window) {
-                unsigned long shift = page_size * (head / page_size);
-                int res;
-
-                res = munmap(buf, page_size * mmap_window);
-                assert(res == 0);
-
-                offset += shift;
-                head -= shift;
-                goto remap;
-        }
-
-        size = event->header.size;
-
-
-        if (!size || process_event(event, offset, head) < 0) {
-
-                /*
-                 * assume we lost track of the stream, check alignment, and
-                 * increment a single u64 in the hope to catch on again 'soon'.
-                 */
-
-                if (unlikely(head & 7))
-                        head &= ~7ULL;
-
-                size = 8;
-        }
-
-        head += size;
-
-        if (offset + head < (unsigned long)perf_stat.st_size)
-                goto more;
-
-        rc = EXIT_SUCCESS;
-        close(input);
-
-        return rc;
+        return mmap_dispatch_perf_file(&header, input_name, 0, 0, &cwdlen, &cwd);
 }
 
 static void print_bad_events(void)
@@ -1934,7 +1849,6 @@ static int __cmd_record(int argc, const char **argv)
 int cmd_sched(int argc, const char **argv, const char *prefix __used)
 {
         symbol__init();
-        page_size = getpagesize();
 
         argc = parse_options(argc, argv, sched_options, sched_usage,
                              PARSE_OPT_STOP_AT_NON_OPTION);
diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index d9abb4ae5f79..fb3f3c220211 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -12,11 +12,9 @@
 #include "util/debug.h"
 
 #include "util/trace-event.h"
+#include "util/data_map.h"
 
 static char             const *input_name = "perf.data";
-static int              input;
-static unsigned long    page_size;
-static unsigned long    mmap_window = 32;
 
 static unsigned long    total = 0;
 static unsigned long    total_comm = 0;
@@ -27,6 +25,9 @@ static struct thread	*last_match;
 static struct perf_header *header;
 static u64              sample_type;
 
+static char             *cwd;
+static int              cwdlen;
+
 
 static int
 process_comm_event(event_t *event, unsigned long offset, unsigned long head)
@@ -112,125 +113,32 @@ process_sample_event(event_t *event, unsigned long offset, unsigned long head)
         return 0;
 }
 
-static int
-process_event(event_t *event, unsigned long offset, unsigned long head)
+static int sample_type_check(u64 type)
 {
-        trace_event(event);
-
-        switch (event->header.type) {
-        case PERF_RECORD_MMAP ... PERF_RECORD_LOST:
-                return 0;
-
-        case PERF_RECORD_COMM:
-                return process_comm_event(event, offset, head);
-
-        case PERF_RECORD_EXIT ... PERF_RECORD_READ:
-                return 0;
+        sample_type = type;
 
-        case PERF_RECORD_SAMPLE:
-                return process_sample_event(event, offset, head);
-
-        case PERF_RECORD_MAX:
-        default:
+        if (!(sample_type & PERF_SAMPLE_RAW)) {
+                fprintf(stderr,
+                        "No trace sample to read. Did you call perf record "
+                        "without -R?");
                 return -1;
         }
 
         return 0;
 }
 
+static struct perf_file_handler file_handler = {
+        .process_sample_event   = process_sample_event,
+        .process_comm_event     = process_comm_event,
+        .sample_type_check      = sample_type_check,
+};
+
 static int __cmd_trace(void)
 {
-        int ret, rc = EXIT_FAILURE;
-        unsigned long offset = 0;
-        unsigned long head = 0;
-        unsigned long shift;
-        struct stat perf_stat;
-        event_t *event;
-        uint32_t size;
-        char *buf;
-
         register_idle_thread(&threads, &last_match);
+        register_perf_file_handler(&file_handler);
 
-        input = open(input_name, O_RDONLY);
-        if (input < 0) {
-                perror("failed to open file");
-                exit(-1);
-        }
-
-        ret = fstat(input, &perf_stat);
-        if (ret < 0) {
-                perror("failed to stat file");
-                exit(-1);
-        }
-
-        if (!perf_stat.st_size) {
-                fprintf(stderr, "zero-sized file, nothing to do!\n");
-                exit(0);
-        }
-        header = perf_header__read(input);
-        head = header->data_offset;
-        sample_type = perf_header__sample_type(header);
-
-        if (!(sample_type & PERF_SAMPLE_RAW))
-                die("No trace sample to read. Did you call perf record "
-                    "without -R?");
-
-        if (load_kernel() < 0) {
-                perror("failed to load kernel symbols");
-                return EXIT_FAILURE;
-        }
-
-        shift = page_size * (head / page_size);
-        offset += shift;
-        head -= shift;
-
-remap:
-        buf = (char *)mmap(NULL, page_size * mmap_window, PROT_READ,
-                           MAP_SHARED, input, offset);
-        if (buf == MAP_FAILED) {
-                perror("failed to mmap file");
-                exit(-1);
-        }
-
-more:
-        event = (event_t *)(buf + head);
-
-        if (head + event->header.size >= page_size * mmap_window) {
-                int res;
-
-                shift = page_size * (head / page_size);
-                res = munmap(buf, page_size * mmap_window);
-                assert(res == 0);
-
-                offset += shift;
-                head -= shift;
-                goto remap;
-        }
-
-        size = event->header.size;
-
-        if (!size || process_event(event, offset, head) < 0) {
-
-                /*
-                 * assume we lost track of the stream, check alignment, and
-                 * increment a single u64 in the hope to catch on again 'soon'.
-                 */
-
-                if (unlikely(head & 7))
-                        head &= ~7ULL;
-
-                size = 8;
-        }
-
-        head += size;
-
-        if (offset + head < (unsigned long)perf_stat.st_size)
-                goto more;
-
-        rc = EXIT_SUCCESS;
-        close(input);
-
-        return rc;
+        return mmap_dispatch_perf_file(&header, input_name, 0, 0, &cwdlen, &cwd);
 }
 
 static const char * const annotate_usage[] = {
@@ -249,7 +157,6 @@ static const struct option options[] = {
 int cmd_trace(int argc, const char **argv, const char *prefix __used)
 {
         symbol__init();
-        page_size = getpagesize();
 
         argc = parse_options(argc, argv, options, annotate_usage, 0);
         if (argc) {
diff --git a/tools/perf/util/data_map.c b/tools/perf/util/data_map.c
new file mode 100644
index 000000000000..242b0555ab91
--- /dev/null
+++ b/tools/perf/util/data_map.c
@@ -0,0 +1,222 @@
+#include "data_map.h"
+#include "symbol.h"
+#include "util.h"
+#include "debug.h"
+
+
+static struct perf_file_handler *curr_handler;
+static unsigned long    mmap_window = 32;
+static char             __cwd[PATH_MAX];
+
+static int
+process_event_stub(event_t *event __used,
+                   unsigned long offset __used,
+                   unsigned long head __used)
+{
+        return 0;
+}
+
+void register_perf_file_handler(struct perf_file_handler *handler)
+{
+        if (!handler->process_sample_event)
+                handler->process_sample_event = process_event_stub;
+        if (!handler->process_mmap_event)
+                handler->process_mmap_event = process_event_stub;
+        if (!handler->process_comm_event)
+                handler->process_comm_event = process_event_stub;
+        if (!handler->process_fork_event)
+                handler->process_fork_event = process_event_stub;
+        if (!handler->process_exit_event)
+                handler->process_exit_event = process_event_stub;
+        if (!handler->process_lost_event)
+                handler->process_lost_event = process_event_stub;
+        if (!handler->process_read_event)
+                handler->process_read_event = process_event_stub;
+        if (!handler->process_throttle_event)
+                handler->process_throttle_event = process_event_stub;
+        if (!handler->process_unthrottle_event)
+                handler->process_unthrottle_event = process_event_stub;
+
+        curr_handler = handler;
+}
+
+static int
+process_event(event_t *event, unsigned long offset, unsigned long head)
+{
+        trace_event(event);
+
+        switch (event->header.type) {
+        case PERF_RECORD_SAMPLE:
+                return curr_handler->process_sample_event(event, offset, head);
+        case PERF_RECORD_MMAP:
+                return curr_handler->process_mmap_event(event, offset, head);
+        case PERF_RECORD_COMM:
+                return curr_handler->process_comm_event(event, offset, head);
+        case PERF_RECORD_FORK:
+                return curr_handler->process_fork_event(event, offset, head);
+        case PERF_RECORD_EXIT:
+                return curr_handler->process_exit_event(event, offset, head);
+        case PERF_RECORD_LOST:
+                return curr_handler->process_lost_event(event, offset, head);
+        case PERF_RECORD_READ:
+                return curr_handler->process_read_event(event, offset, head);
+        case PERF_RECORD_THROTTLE:
+                return curr_handler->process_throttle_event(event, offset, head);
+        case PERF_RECORD_UNTHROTTLE:
+                return curr_handler->process_unthrottle_event(event, offset, head);
+        default:
+                curr_handler->total_unknown++;
+                return -1;
+        }
+}
+
+int mmap_dispatch_perf_file(struct perf_header **pheader,
+                            const char *input_name,
+                            int force,
+                            int full_paths,
+                            int *cwdlen,
+                            char **cwd)
+{
+        int ret, rc = EXIT_FAILURE;
+        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)
+                die("Forgot to register perf file handler");
+
+        page_size = getpagesize();
+
+        input = open(input_name, O_RDONLY);
+        if (input < 0) {
+                fprintf(stderr, " failed to open file: %s", input_name);
+                if (!strcmp(input_name, "perf.data"))
+                        fprintf(stderr, "  (try 'perf record' first)");
+                fprintf(stderr, "\n");
+                exit(-1);
+        }
+
+        ret = fstat(input, &input_stat);
+        if (ret < 0) {
+                perror("failed to stat file");
+                exit(-1);
+        }
+
+        if (!force && input_stat.st_uid && (input_stat.st_uid != geteuid())) {
+                fprintf(stderr, "file: %s not owned by current user or root\n",
+                        input_name);
+                exit(-1);
+        }
+
+        if (!input_stat.st_size) {
+                fprintf(stderr, "zero-sized file, nothing to do!\n");
+                exit(0);
+        }
+
+        *pheader = perf_header__read(input);
+        header = *pheader;
+        head = header->data_offset;
+
+        sample_type = perf_header__sample_type(header);
+
+        if (curr_handler->sample_type_check)
+                if (curr_handler->sample_type_check(sample_type) < 0)
+                        exit(-1);
+
+        if (load_kernel() < 0) {
+                perror("failed to load kernel symbols");
+                return EXIT_FAILURE;
+        }
+
+        if (!full_paths) {
+                if (getcwd(__cwd, sizeof(__cwd)) == NULL) {
+                        perror("failed to get the current directory");
+                        return EXIT_FAILURE;
+                }
+                *cwd = __cwd;
+                *cwdlen = strlen(*cwd);
+        } else {
+                *cwd = NULL;
+                *cwdlen = 0;
+        }
+
+        shift = page_size * (head / page_size);
+        offset += shift;
+        head -= shift;
+
+remap:
+        buf = (char *)mmap(NULL, page_size * mmap_window, PROT_READ,
+                           MAP_SHARED, input, offset);
+        if (buf == MAP_FAILED) {
+                perror("failed to mmap file");
+                exit(-1);
+        }
+
+more:
+        event = (event_t *)(buf + head);
+
+        size = event->header.size;
+        if (!size)
+                size = 8;
+
+        if (head + event->header.size >= page_size * mmap_window) {
+                int munmap_ret;
+
+                shift = page_size * (head / page_size);
+
+                munmap_ret = munmap(buf, page_size * mmap_window);
+                assert(munmap_ret == 0);
+
+                offset += shift;
+                head -= shift;
+                goto remap;
+        }
+
+        size = event->header.size;
+
+        dump_printf("\n%p [%p]: event: %d\n",
+                        (void *)(offset + head),
+                        (void *)(long)event->header.size,
+                        event->header.type);
+
+        if (!size || process_event(event, offset, head) < 0) {
+
+                dump_printf("%p [%p]: skipping unknown header type: %d\n",
+                        (void *)(offset + head),
+                        (void *)(long)(event->header.size),
+                        event->header.type);
+
+                /*
+                 * assume we lost track of the stream, check alignment, and
+                 * increment a single u64 in the hope to catch on again 'soon'.
+                 */
+
+                if (unlikely(head & 7))
+                        head &= ~7ULL;
+
+                size = 8;
+        }
+
+        head += size;
+
+        if (offset + head >= header->data_offset + header->data_size)
+                goto done;
+
+        if (offset + head < (unsigned long)input_stat.st_size)
+                goto more;
+
+done:
+        rc = EXIT_SUCCESS;
+        close(input);
+
+        return rc;
+}
+
+
diff --git a/tools/perf/util/data_map.h b/tools/perf/util/data_map.h
new file mode 100644
index 000000000000..716d1053b074
--- /dev/null
+++ b/tools/perf/util/data_map.h
@@ -0,0 +1,31 @@
+#ifndef __PERF_DATAMAP_H
+#define __PERF_DATAMAP_H
+
+#include "event.h"
+#include "header.h"
+
+typedef int (*event_type_handler_t)(event_t *, unsigned long, unsigned long);
+
+struct perf_file_handler {
+        event_type_handler_t    process_sample_event;
+        event_type_handler_t    process_mmap_event;
+        event_type_handler_t    process_comm_event;
+        event_type_handler_t    process_fork_event;
+        event_type_handler_t    process_exit_event;
+        event_type_handler_t    process_lost_event;
+        event_type_handler_t    process_read_event;
+        event_type_handler_t    process_throttle_event;
+        event_type_handler_t    process_unthrottle_event;
+        int                     (*sample_type_check)(u64 sample_type);
+        unsigned long           total_unknown;
+};
+
+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);
+
+#endif