LIB_H += util/debug.h
 LIB_H += util/debugfs.h
 LIB_H += util/event.h
+LIB_H += util/evsel.h
 LIB_H += util/exec_cmd.h
 LIB_H += util/types.h
 LIB_H += util/levenshtein.h
 LIB_H += util/parse-events.h
 LIB_H += util/quote.h
 LIB_H += util/util.h
+LIB_H += util/xyarray.h
 LIB_H += util/header.h
 LIB_H += util/help.h
 LIB_H += util/session.h
 LIB_OBJS += $(OUTPUT)util/debugfs.o
 LIB_OBJS += $(OUTPUT)util/environment.o
 LIB_OBJS += $(OUTPUT)util/event.o
+LIB_OBJS += $(OUTPUT)util/evsel.o
 LIB_OBJS += $(OUTPUT)util/exec_cmd.o
 LIB_OBJS += $(OUTPUT)util/help.o
 LIB_OBJS += $(OUTPUT)util/levenshtein.o
 LIB_OBJS += $(OUTPUT)util/hist.o
 LIB_OBJS += $(OUTPUT)util/probe-event.o
 LIB_OBJS += $(OUTPUT)util/util.o
+LIB_OBJS += $(OUTPUT)util/xyarray.o
 LIB_OBJS += $(OUTPUT)util/cpumap.o
 
 BUILTIN_OBJS += $(OUTPUT)builtin-annotate.o
 
 
 #include "util/header.h"
 #include "util/event.h"
+#include "util/evsel.h"
 #include "util/debug.h"
 #include "util/session.h"
 #include "util/symbol.h"
 #include <sched.h>
 #include <sys/mman.h>
 
+#define FD(e, x, y) (*(int *)xyarray__entry(e->fd, x, y))
+
 enum write_mode_t {
        WRITE_FORCE,
        WRITE_APPEND
 };
 
-static int                     *fd[MAX_NR_CPUS][MAX_COUNTERS];
-
 static u64                     user_interval                   = ULLONG_MAX;
 static u64                     default_interval                =      0;
 static u64                     sample_type;
 static const char              *cpu_list;
 
 struct mmap_data {
-       int                     counter;
        void                    *base;
        unsigned int            mask;
        unsigned int            prev;
        return h_attr;
 }
 
-static void create_counter(int counter, int cpu)
+static void create_counter(struct perf_evsel *evsel, int cpu)
 {
-       char *filter = filters[counter];
-       struct perf_event_attr *attr = attrs + counter;
+       char *filter = evsel->filter;
+       struct perf_event_attr *attr = &evsel->attr;
        struct perf_header_attr *h_attr;
-       int track = !counter; /* only the first counter needs these */
+       int track = !evsel->idx; /* only the first counter needs these */
        int thread_index;
        int ret;
        struct {
 
        for (thread_index = 0; thread_index < thread_num; thread_index++) {
 try_again:
-               fd[nr_cpu][counter][thread_index] = sys_perf_event_open(attr,
-                               all_tids[thread_index], cpu, group_fd, 0);
+               FD(evsel, nr_cpu, thread_index) = sys_perf_event_open(attr, all_tids[thread_index], cpu, group_fd, 0);
 
-               if (fd[nr_cpu][counter][thread_index] < 0) {
+               if (FD(evsel, nr_cpu, thread_index) < 0) {
                        int err = errno;
 
                        if (err == EPERM || err == EACCES)
                        }
                        printf("\n");
                        error("sys_perf_event_open() syscall returned with %d (%s).  /bin/dmesg may provide additional information.\n",
-                                       fd[nr_cpu][counter][thread_index], strerror(err));
+                             FD(evsel, nr_cpu, thread_index), strerror(err));
 
 #if defined(__i386__) || defined(__x86_64__)
                        if (attr->type == PERF_TYPE_HARDWARE && err == EOPNOTSUPP)
                        exit(-1);
                }
 
-               h_attr = get_header_attr(attr, counter);
+               h_attr = get_header_attr(attr, evsel->idx);
                if (h_attr == NULL)
                        die("nomem\n");
 
                        }
                }
 
-               if (read(fd[nr_cpu][counter][thread_index], &read_data, sizeof(read_data)) == -1) {
+               if (read(FD(evsel, nr_cpu, thread_index), &read_data, sizeof(read_data)) == -1) {
                        perror("Unable to read perf file descriptor");
                        exit(-1);
                }
                        exit(-1);
                }
 
-               assert(fd[nr_cpu][counter][thread_index] >= 0);
-               fcntl(fd[nr_cpu][counter][thread_index], F_SETFL, O_NONBLOCK);
+               assert(FD(evsel, nr_cpu, thread_index) >= 0);
+               fcntl(FD(evsel, nr_cpu, thread_index), F_SETFL, O_NONBLOCK);
 
                /*
                 * First counter acts as the group leader:
                 */
                if (group && group_fd == -1)
-                       group_fd = fd[nr_cpu][counter][thread_index];
-
-               if (counter || thread_index) {
-                       ret = ioctl(fd[nr_cpu][counter][thread_index],
-                                       PERF_EVENT_IOC_SET_OUTPUT,
-                                       fd[nr_cpu][0][0]);
+                       group_fd = FD(evsel, nr_cpu, thread_index);
+
+               if (evsel->idx || thread_index) {
+                       struct perf_evsel *first;
+                       first = list_entry(evsel_list.next, struct perf_evsel, node);
+                       ret = ioctl(FD(evsel, nr_cpu, thread_index),
+                                   PERF_EVENT_IOC_SET_OUTPUT,
+                                   FD(first, nr_cpu, 0));
                        if (ret) {
                                error("failed to set output: %d (%s)\n", errno,
                                                strerror(errno));
                                exit(-1);
                        }
                } else {
-                       mmap_array[nr_cpu].counter = counter;
                        mmap_array[nr_cpu].prev = 0;
                        mmap_array[nr_cpu].mask = mmap_pages*page_size - 1;
                        mmap_array[nr_cpu].base = mmap(NULL, (mmap_pages+1)*page_size,
-                               PROT_READ|PROT_WRITE, MAP_SHARED, fd[nr_cpu][counter][thread_index], 0);
+                               PROT_READ | PROT_WRITE, MAP_SHARED, FD(evsel, nr_cpu, thread_index), 0);
                        if (mmap_array[nr_cpu].base == MAP_FAILED) {
                                error("failed to mmap with %d (%s)\n", errno, strerror(errno));
                                exit(-1);
                        }
 
-                       event_array[nr_poll].fd = fd[nr_cpu][counter][thread_index];
+                       event_array[nr_poll].fd = FD(evsel, nr_cpu, thread_index);
                        event_array[nr_poll].events = POLLIN;
                        nr_poll++;
                }
 
                if (filter != NULL) {
-                       ret = ioctl(fd[nr_cpu][counter][thread_index],
-                                       PERF_EVENT_IOC_SET_FILTER, filter);
+                       ret = ioctl(FD(evsel, nr_cpu, thread_index),
+                                   PERF_EVENT_IOC_SET_FILTER, filter);
                        if (ret) {
                                error("failed to set filter with %d (%s)\n", errno,
                                                strerror(errno));
 
 static void open_counters(int cpu)
 {
-       int counter;
+       struct perf_evsel *pos;
 
        group_fd = -1;
-       for (counter = 0; counter < nr_counters; counter++)
-               create_counter(counter, cpu);
+
+       list_for_each_entry(pos, &evsel_list, node)
+               create_counter(pos, cpu);
 
        nr_cpu++;
 }
 
 static int __cmd_record(int argc, const char **argv)
 {
-       int i, counter;
+       int i;
        struct stat st;
        int flags;
        int err;
                        goto out_delete_session;
        }
 
-       if (have_tracepoints(attrs, nr_counters))
+       if (have_tracepoints(&evsel_list))
                perf_header__set_feat(&session->header, HEADER_TRACE_INFO);
 
        /*
                close(child_ready_pipe[0]);
        }
 
-       nr_cpus = read_cpu_map(cpu_list);
-       if (nr_cpus < 1) {
-               perror("failed to collect number of CPUs");
-               return -1;
-       }
-
        if (!system_wide && no_inherit && !cpu_list) {
                open_counters(-1);
        } else {
                        return err;
                }
 
-               if (have_tracepoints(attrs, nr_counters)) {
+               if (have_tracepoints(&evsel_list)) {
                        /*
                         * FIXME err <= 0 here actually means that
                         * there were no tracepoints so its not really
                         * return this more properly and also
                         * propagate errors that now are calling die()
                         */
-                       err = event__synthesize_tracing_data(output, attrs,
-                                                            nr_counters,
+                       err = event__synthesize_tracing_data(output, &evsel_list,
                                                             process_synthesized_event,
                                                             session);
                        if (err <= 0) {
 
                if (done) {
                        for (i = 0; i < nr_cpu; i++) {
-                               for (counter = 0;
-                                       counter < nr_counters;
-                                       counter++) {
+                               struct perf_evsel *pos;
+
+                               list_for_each_entry(pos, &evsel_list, node) {
                                        for (thread = 0;
                                                thread < thread_num;
                                                thread++)
-                                               ioctl(fd[i][counter][thread],
+                                               ioctl(FD(pos, i, thread),
                                                        PERF_EVENT_IOC_DISABLE);
                                }
                        }
 
 int cmd_record(int argc, const char **argv, const char *prefix __used)
 {
-       int i, j, err = -ENOMEM;
+       int err = -ENOMEM;
+       struct perf_evsel *pos;
 
        argc = parse_options(argc, argv, record_options, record_usage,
                            PARSE_OPT_STOP_AT_NON_OPTION);
        if (no_buildid_cache || no_buildid)
                disable_buildid_cache();
 
-       if (!nr_counters) {
-               nr_counters     = 1;
-               attrs[0].type   = PERF_TYPE_HARDWARE;
-               attrs[0].config = PERF_COUNT_HW_CPU_CYCLES;
+       if (list_empty(&evsel_list) && perf_evsel_list__create_default() < 0) {
+               pr_err("Not enough memory for event selector list\n");
+               goto out_symbol_exit;
        }
 
        if (target_pid != -1) {
                thread_num = 1;
        }
 
-       for (i = 0; i < MAX_NR_CPUS; i++) {
-               for (j = 0; j < MAX_COUNTERS; j++) {
-                       fd[i][j] = malloc(sizeof(int)*thread_num);
-                       if (!fd[i][j])
-                               goto out_free_fd;
-               }
+       nr_cpus = read_cpu_map(cpu_list);
+       if (nr_cpus < 1) {
+               perror("failed to collect number of CPUs");
+               return -1;
+       }
+
+       list_for_each_entry(pos, &evsel_list, node) {
+               if (perf_evsel__alloc_fd(pos, nr_cpus, thread_num) < 0)
+                       goto out_free_fd;
        }
        event_array = malloc(
                sizeof(struct pollfd)*MAX_NR_CPUS*MAX_COUNTERS*thread_num);
 out_free_event_array:
        free(event_array);
 out_free_fd:
-       for (i = 0; i < MAX_NR_CPUS; i++) {
-               for (j = 0; j < MAX_COUNTERS; j++)
-                       free(fd[i][j]);
-       }
+       list_for_each_entry(pos, &evsel_list, node)
+               perf_evsel__free_fd(pos);
        free(all_tids);
        all_tids = NULL;
 out_symbol_exit:
 
 #include "util/parse-options.h"
 #include "util/parse-events.h"
 #include "util/event.h"
+#include "util/evsel.h"
 #include "util/debug.h"
 #include "util/header.h"
 #include "util/cpumap.h"
 #include <math.h>
 #include <locale.h>
 
+#define FD(e, x, y) (*(int *)xyarray__entry(e->fd, x, y))
+
 #define DEFAULT_SEPARATOR      " "
 
 static struct perf_event_attr default_attrs[] = {
 static const char              *csv_sep                        = NULL;
 static bool                    csv_output                      = false;
 
-
-static int                     *fd[MAX_NR_CPUS][MAX_COUNTERS];
-
-static int                     event_scaled[MAX_COUNTERS];
-
-static struct {
+struct cpu_counts {
        u64 val;
        u64 ena;
        u64 run;
-} cpu_counts[MAX_NR_CPUS][MAX_COUNTERS];
+};
 
 static volatile int done = 0;
 
        double n, mean, M2;
 };
 
+struct perf_stat {
+       struct stats      res_stats[3];
+       int               scaled;
+       struct cpu_counts cpu_counts[];
+};
+
+static int perf_evsel__alloc_stat_priv(struct perf_evsel *evsel, int ncpus)
+{
+       size_t priv_size = (sizeof(struct perf_stat) +
+                           (ncpus * sizeof(struct cpu_counts)));
+       evsel->priv = zalloc(priv_size);
+       return evsel->priv == NULL ? -ENOMEM : 0;
+}
+
+static void perf_evsel__free_stat_priv(struct perf_evsel *evsel)
+{
+       free(evsel->priv);
+       evsel->priv = NULL;
+}
+
 static void update_stats(struct stats *stats, u64 val)
 {
        double delta;
        return sqrt(variance_mean);
 }
 
-struct stats                   event_res_stats[MAX_COUNTERS][3];
 struct stats                   runtime_nsecs_stats[MAX_NR_CPUS];
 struct stats                   runtime_cycles_stats[MAX_NR_CPUS];
 struct stats                   runtime_branches_stats[MAX_NR_CPUS];
 struct stats                   walltime_nsecs_stats;
 
-#define MATCH_EVENT(t, c, counter)                     \
-       (attrs[counter].type == PERF_TYPE_##t &&        \
-        attrs[counter].config == PERF_COUNT_##c)
+#define MATCH_EVENT(t, c, evsel)                       \
+       (evsel->attr.type == PERF_TYPE_##t &&   \
+        evsel->attr.config == PERF_COUNT_##c)
 
 #define ERR_PERF_OPEN \
 "counter %d, sys_perf_event_open() syscall returned with %d (%s).  /bin/dmesg may provide additional information."
 
-static int create_perf_stat_counter(int counter, bool *perm_err)
+static int create_perf_stat_counter(struct perf_evsel *evsel, bool *perm_err)
 {
-       struct perf_event_attr *attr = attrs + counter;
+       struct perf_event_attr *attr = &evsel->attr;
        int thread;
        int ncreated = 0;
 
                int cpu;
 
                for (cpu = 0; cpu < nr_cpus; cpu++) {
-                       fd[cpu][counter][0] = sys_perf_event_open(attr,
+                       FD(evsel, cpu, 0) = sys_perf_event_open(attr,
                                        -1, cpumap[cpu], -1, 0);
-                       if (fd[cpu][counter][0] < 0) {
+                       if (FD(evsel, cpu, 0) < 0) {
                                if (errno == EPERM || errno == EACCES)
                                        *perm_err = true;
-                               error(ERR_PERF_OPEN, counter,
-                                        fd[cpu][counter][0], strerror(errno));
+                               error(ERR_PERF_OPEN, evsel->idx,
+                                       FD(evsel, cpu, 0), strerror(errno));
                        } else {
                                ++ncreated;
                        }
                        attr->enable_on_exec = 1;
                }
                for (thread = 0; thread < thread_num; thread++) {
-                       fd[0][counter][thread] = sys_perf_event_open(attr,
+                       FD(evsel, 0, thread) = sys_perf_event_open(attr,
                                all_tids[thread], -1, -1, 0);
-                       if (fd[0][counter][thread] < 0) {
+                       if (FD(evsel, 0, thread) < 0) {
                                if (errno == EPERM || errno == EACCES)
                                        *perm_err = true;
-                               error(ERR_PERF_OPEN, counter,
-                                        fd[0][counter][thread],
+                               error(ERR_PERF_OPEN, evsel->idx,
+                                       FD(evsel, 0, thread),
                                         strerror(errno));
                        } else {
                                ++ncreated;
 /*
  * Does the counter have nsecs as a unit?
  */
-static inline int nsec_counter(int counter)
+static inline int nsec_counter(struct perf_evsel *counter)
 {
        if (MATCH_EVENT(SOFTWARE, SW_CPU_CLOCK, counter) ||
            MATCH_EVENT(SOFTWARE, SW_TASK_CLOCK, counter))
  * Read out the results of a single counter:
  * aggregate counts across CPUs in system-wide mode
  */
-static void read_counter_aggr(int counter)
+static void read_counter_aggr(struct perf_evsel *counter)
 {
+       struct perf_stat *ps = counter->priv;
        u64 count[3], single_count[3];
        int cpu;
        size_t res, nv;
        nv = scale ? 3 : 1;
        for (cpu = 0; cpu < nr_cpus; cpu++) {
                for (thread = 0; thread < thread_num; thread++) {
-                       if (fd[cpu][counter][thread] < 0)
+                       if (FD(counter, cpu, thread) < 0)
                                continue;
 
-                       res = read(fd[cpu][counter][thread],
+                       res = read(FD(counter, cpu, thread),
                                        single_count, nv * sizeof(u64));
                        assert(res == nv * sizeof(u64));
 
-                       close(fd[cpu][counter][thread]);
-                       fd[cpu][counter][thread] = -1;
+                       close(FD(counter, cpu, thread));
+                       FD(counter, cpu, thread) = -1;
 
                        count[0] += single_count[0];
                        if (scale) {
        scaled = 0;
        if (scale) {
                if (count[2] == 0) {
-                       event_scaled[counter] = -1;
+                       ps->scaled = -1;
                        count[0] = 0;
                        return;
                }
 
                if (count[2] < count[1]) {
-                       event_scaled[counter] = 1;
+                       ps->scaled = 1;
                        count[0] = (unsigned long long)
                                ((double)count[0] * count[1] / count[2] + 0.5);
                }
        }
 
        for (i = 0; i < 3; i++)
-               update_stats(&event_res_stats[counter][i], count[i]);
+               update_stats(&ps->res_stats[i], count[i]);
 
        if (verbose) {
                fprintf(stderr, "%s: %Ld %Ld %Ld\n", event_name(counter),
  * Read out the results of a single counter:
  * do not aggregate counts across CPUs in system-wide mode
  */
-static void read_counter(int counter)
+static void read_counter(struct perf_evsel *counter)
 {
+       struct cpu_counts *cpu_counts = counter->priv;
        u64 count[3];
        int cpu;
        size_t res, nv;
 
        for (cpu = 0; cpu < nr_cpus; cpu++) {
 
-               if (fd[cpu][counter][0] < 0)
+               if (FD(counter, cpu, 0) < 0)
                        continue;
 
-               res = read(fd[cpu][counter][0], count, nv * sizeof(u64));
+               res = read(FD(counter, cpu, 0), count, nv * sizeof(u64));
 
                assert(res == nv * sizeof(u64));
 
-               close(fd[cpu][counter][0]);
-               fd[cpu][counter][0] = -1;
+               close(FD(counter, cpu, 0));
+               FD(counter, cpu, 0) = -1;
 
                if (scale) {
                        if (count[2] == 0) {
                                ((double)count[0] * count[1] / count[2] + 0.5);
                        }
                }
-               cpu_counts[cpu][counter].val = count[0]; /* scaled count */
-               cpu_counts[cpu][counter].ena = count[1];
-               cpu_counts[cpu][counter].run = count[2];
+               cpu_counts[cpu].val = count[0]; /* scaled count */
+               cpu_counts[cpu].ena = count[1];
+               cpu_counts[cpu].run = count[2];
 
                if (MATCH_EVENT(SOFTWARE, SW_TASK_CLOCK, counter))
                        update_stats(&runtime_nsecs_stats[cpu], count[0]);
 static int run_perf_stat(int argc __used, const char **argv)
 {
        unsigned long long t0, t1;
+       struct perf_evsel *counter;
        int status = 0;
-       int counter, ncreated = 0;
+       int ncreated = 0;
        int child_ready_pipe[2], go_pipe[2];
        bool perm_err = false;
        const bool forks = (argc > 0);
                close(child_ready_pipe[0]);
        }
 
-       for (counter = 0; counter < nr_counters; counter++)
+       list_for_each_entry(counter, &evsel_list, node)
                ncreated += create_perf_stat_counter(counter, &perm_err);
 
        if (ncreated < nr_counters) {
        update_stats(&walltime_nsecs_stats, t1 - t0);
 
        if (no_aggr) {
-               for (counter = 0; counter < nr_counters; counter++)
+               list_for_each_entry(counter, &evsel_list, node)
                        read_counter(counter);
        } else {
-               for (counter = 0; counter < nr_counters; counter++)
+               list_for_each_entry(counter, &evsel_list, node)
                        read_counter_aggr(counter);
        }
        return WEXITSTATUS(status);
 }
 
-static void print_noise(int counter, double avg)
+static void print_noise(struct perf_evsel *evsel, double avg)
 {
+       struct perf_stat *ps;
+
        if (run_count == 1)
                return;
 
+       ps = evsel->priv;
        fprintf(stderr, "   ( +- %7.3f%% )",
-                       100 * stddev_stats(&event_res_stats[counter][0]) / avg);
+                       100 * stddev_stats(&ps->res_stats[0]) / avg);
 }
 
-static void nsec_printout(int cpu, int counter, double avg)
+static void nsec_printout(int cpu, struct perf_evsel *counter, double avg)
 {
        double msecs = avg / 1e6;
        char cpustr[16] = { '\0', };
        }
 }
 
-static void abs_printout(int cpu, int counter, double avg)
+static void abs_printout(int cpu, struct perf_evsel *counter, double avg)
 {
        double total, ratio = 0.0;
        char cpustr[16] = { '\0', };
  * Print out the results of a single counter:
  * aggregated counts in system-wide mode
  */
-static void print_counter_aggr(int counter)
+static void print_counter_aggr(struct perf_evsel *counter)
 {
-       double avg = avg_stats(&event_res_stats[counter][0]);
-       int scaled = event_scaled[counter];
+       struct perf_stat *ps = counter->priv;
+       double avg = avg_stats(&ps->res_stats[0]);
+       int scaled = ps->scaled;
 
        if (scaled == -1) {
                fprintf(stderr, "%*s%s%-24s\n",
        if (scaled) {
                double avg_enabled, avg_running;
 
-               avg_enabled = avg_stats(&event_res_stats[counter][1]);
-               avg_running = avg_stats(&event_res_stats[counter][2]);
+               avg_enabled = avg_stats(&ps->res_stats[1]);
+               avg_running = avg_stats(&ps->res_stats[2]);
 
                fprintf(stderr, "  (scaled from %.2f%%)",
                                100 * avg_running / avg_enabled);
  * Print out the results of a single counter:
  * does not use aggregated count in system-wide
  */
-static void print_counter(int counter)
+static void print_counter(struct perf_evsel *counter)
 {
+       struct perf_stat *ps = counter->priv;
        u64 ena, run, val;
        int cpu;
 
        for (cpu = 0; cpu < nr_cpus; cpu++) {
-               val = cpu_counts[cpu][counter].val;
-               ena = cpu_counts[cpu][counter].ena;
-               run = cpu_counts[cpu][counter].run;
+               val = ps->cpu_counts[cpu].val;
+               ena = ps->cpu_counts[cpu].ena;
+               run = ps->cpu_counts[cpu].run;
                if (run == 0 || ena == 0) {
                        fprintf(stderr, "CPU%*d%s%*s%s%-24s",
                                csv_output ? 0 : -4,
 
 static void print_stat(int argc, const char **argv)
 {
-       int i, counter;
+       struct perf_evsel *counter;
+       int i;
 
        fflush(stdout);
 
        }
 
        if (no_aggr) {
-               for (counter = 0; counter < nr_counters; counter++)
+               list_for_each_entry(counter, &evsel_list, node)
                        print_counter(counter);
        } else {
-               for (counter = 0; counter < nr_counters; counter++)
+               list_for_each_entry(counter, &evsel_list, node)
                        print_counter_aggr(counter);
        }
 
 
 int cmd_stat(int argc, const char **argv, const char *prefix __used)
 {
-       int status;
-       int i,j;
+       struct perf_evsel *pos;
+       int status = -ENOMEM;
 
        setlocale(LC_ALL, "");
 
 
        /* Set attrs and nr_counters if no event is selected and !null_run */
        if (!null_run && !nr_counters) {
-               memcpy(attrs, default_attrs, sizeof(default_attrs));
+               size_t c;
+
                nr_counters = ARRAY_SIZE(default_attrs);
+
+               for (c = 0; c < ARRAY_SIZE(default_attrs); ++c) {
+                       pos = perf_evsel__new(default_attrs[c].type,
+                                             default_attrs[c].config,
+                                             nr_counters);
+                       if (pos == NULL)
+                               goto out;
+                       list_add(&pos->node, &evsel_list);
+               }
        }
 
        if (system_wide)
                thread_num = 1;
        }
 
-       for (i = 0; i < MAX_NR_CPUS; i++) {
-               for (j = 0; j < MAX_COUNTERS; j++) {
-                       fd[i][j] = malloc(sizeof(int)*thread_num);
-                       if (!fd[i][j])
-                               return -ENOMEM;
-               }
+       list_for_each_entry(pos, &evsel_list, node) {
+               if (perf_evsel__alloc_stat_priv(pos, nr_cpus) < 0 ||
+                   perf_evsel__alloc_fd(pos, nr_cpus, thread_num) < 0)
+                       goto out_free_fd;
        }
 
        /*
 
        if (status != -1)
                print_stat(argc, argv);
-
+out_free_fd:
+       list_for_each_entry(pos, &evsel_list, node) {
+               perf_evsel__free_fd(pos);
+               perf_evsel__free_stat_priv(pos);
+       }
+out:
        return status;
 }
 
 #include "perf.h"
 
 #include "util/color.h"
+#include "util/evsel.h"
 #include "util/session.h"
 #include "util/symbol.h"
 #include "util/thread.h"
 #include "util/parse-options.h"
 #include "util/parse-events.h"
 #include "util/cpumap.h"
+#include "util/xyarray.h"
 
 #include "util/debug.h"
 
 #include <linux/unistd.h>
 #include <linux/types.h>
 
-static int                     *fd[MAX_NR_CPUS][MAX_COUNTERS];
+#define FD(e, x, y) (*(int *)xyarray__entry(e->fd, x, y))
 
 static bool                    system_wide                     =  false;
 
 struct sym_entry               *sym_filter_entry_sched         =   NULL;
 static int                     sym_pcnt_filter                 =      5;
 static int                     sym_counter                     =      0;
+static struct perf_evsel       *sym_evsel                      =   NULL;
 static int                     display_weighted                =     -1;
 static const char              *cpu_list;
 
                return;
 
        symbol = sym_entry__symbol(syme);
-       printf("Showing %s for %s\n", event_name(sym_counter), symbol->name);
+       printf("Showing %s for %s\n", event_name(sym_evsel), symbol->name);
        printf("  Events  Pcnt (>=%d%%)\n", sym_pcnt_filter);
 
        pthread_mutex_lock(&syme->src->lock);
 static void print_sym_table(void)
 {
        int printed = 0, j;
-       int counter, snap = !display_weighted ? sym_counter : 0;
+       struct perf_evsel *counter;
+       int snap = !display_weighted ? sym_counter : 0;
        float samples_per_sec = samples/delay_secs;
        float ksamples_per_sec = kernel_samples/delay_secs;
        float us_samples_per_sec = (us_samples)/delay_secs;
        }
 
        if (nr_counters == 1 || !display_weighted) {
-               printf("%Ld", (u64)attrs[0].sample_period);
+               struct perf_evsel *first;
+               first = list_entry(evsel_list.next, struct perf_evsel, node);
+               printf("%Ld", first->attr.sample_period);
                if (freq)
                        printf("Hz ");
                else
        }
 
        if (!display_weighted)
-               printf("%s", event_name(sym_counter));
-       else for (counter = 0; counter < nr_counters; counter++) {
-               if (counter)
+               printf("%s", event_name(sym_evsel));
+       else list_for_each_entry(counter, &evsel_list, node) {
+               if (counter->idx)
                        printf("/");
 
                printf("%s", event_name(counter));
        fprintf(stdout, "\t[e]     display entries (lines).           \t(%d)\n", print_entries);
 
        if (nr_counters > 1)
-               fprintf(stdout, "\t[E]     active event counter.              \t(%s)\n", event_name(sym_counter));
+               fprintf(stdout, "\t[E]     active event counter.              \t(%s)\n", event_name(sym_evsel));
 
        fprintf(stdout, "\t[f]     profile display filter (count).    \t(%d)\n", count_filter);
 
                        break;
                case 'E':
                        if (nr_counters > 1) {
-                               int i;
-
                                fprintf(stderr, "\nAvailable events:");
-                               for (i = 0; i < nr_counters; i++)
-                                       fprintf(stderr, "\n\t%d %s", i, event_name(i));
+
+                               list_for_each_entry(sym_evsel, &evsel_list, node)
+                                       fprintf(stderr, "\n\t%d %s", sym_evsel->idx, event_name(sym_evsel));
 
                                prompt_integer(&sym_counter, "Enter details event counter");
 
                                if (sym_counter >= nr_counters) {
-                                       fprintf(stderr, "Sorry, no such event, using %s.\n", event_name(0));
+                                       sym_evsel = list_entry(evsel_list.next, struct perf_evsel, node);
                                        sym_counter = 0;
+                                       fprintf(stderr, "Sorry, no such event, using %s.\n", event_name(sym_evsel));
                                        sleep(1);
+                                       break;
                                }
+                               list_for_each_entry(sym_evsel, &evsel_list, node)
+                                       if (sym_evsel->idx == sym_counter)
+                                               break;
                        } else sym_counter = 0;
                        break;
                case 'f':
 
 static void event__process_sample(const event_t *self,
                                  struct sample_data *sample,
-                                 struct perf_session *session, int counter)
+                                 struct perf_session *session,
+                                 struct perf_evsel *evsel)
 {
        u64 ip = self->ip.ip;
        struct sym_entry *syme;
 
        syme = symbol__priv(al.sym);
        if (!syme->skip) {
-               syme->count[counter]++;
+               syme->count[evsel->idx]++;
                syme->origin = origin;
-               record_precise_ip(syme, counter, ip);
+               record_precise_ip(syme, evsel->idx, ip);
                pthread_mutex_lock(&active_symbols_lock);
                if (list_empty(&syme->node) || !syme->node.next)
                        __list_insert_active_sym(syme);
 }
 
 struct mmap_data {
-       int                     counter;
        void                    *base;
        int                     mask;
        unsigned int            prev;
 };
 
+static int perf_evsel__alloc_mmap_per_thread(struct perf_evsel *evsel,
+                                            int ncpus, int nthreads)
+{
+       evsel->priv = xyarray__new(ncpus, nthreads, sizeof(struct mmap_data));
+       return evsel->priv != NULL ? 0 : -ENOMEM;
+}
+
+static void perf_evsel__free_mmap(struct perf_evsel *evsel)
+{
+       xyarray__delete(evsel->priv);
+       evsel->priv = NULL;
+}
+
 static unsigned int mmap_read_head(struct mmap_data *md)
 {
        struct perf_event_mmap_page *pc = md->base;
 }
 
 static void perf_session__mmap_read_counter(struct perf_session *self,
-                                           struct mmap_data *md)
+                                           struct perf_evsel *evsel,
+                                           int cpu, int thread_idx)
 {
+       struct xyarray *mmap_array = evsel->priv;
+       struct mmap_data *md = xyarray__entry(mmap_array, cpu, thread_idx);
        unsigned int head = mmap_read_head(md);
        unsigned int old = md->prev;
        unsigned char *data = md->base + page_size;
 
                event__parse_sample(event, self, &sample);
                if (event->header.type == PERF_RECORD_SAMPLE)
-                       event__process_sample(event, &sample, self, md->counter);
+                       event__process_sample(event, &sample, self, evsel);
                else
                        event__process(event, &sample, self);
                old += size;
 }
 
 static struct pollfd *event_array;
-static struct mmap_data *mmap_array[MAX_NR_CPUS][MAX_COUNTERS];
 
 static void perf_session__mmap_read(struct perf_session *self)
 {
-       int i, counter, thread_index;
+       struct perf_evsel *counter;
+       int i, thread_index;
 
        for (i = 0; i < nr_cpus; i++) {
-               for (counter = 0; counter < nr_counters; counter++)
+               list_for_each_entry(counter, &evsel_list, node) {
                        for (thread_index = 0;
                                thread_index < thread_num;
                                thread_index++) {
                                perf_session__mmap_read_counter(self,
-                                       &mmap_array[i][counter][thread_index]);
+                                       counter, i, thread_index);
                        }
+               }
        }
 }
 
 int nr_poll;
 int group_fd;
 
-static void start_counter(int i, int counter)
+static void start_counter(int i, struct perf_evsel *evsel)
 {
+       struct xyarray *mmap_array = evsel->priv;
+       struct mmap_data *mm;
        struct perf_event_attr *attr;
        int cpu = -1;
        int thread_index;
        if (target_tid == -1)
                cpu = cpumap[i];
 
-       attr = attrs + counter;
+       attr = &evsel->attr;
 
        attr->sample_type       = PERF_SAMPLE_IP | PERF_SAMPLE_TID;
 
 
        for (thread_index = 0; thread_index < thread_num; thread_index++) {
 try_again:
-               fd[i][counter][thread_index] = sys_perf_event_open(attr,
+               FD(evsel, i, thread_index) = sys_perf_event_open(attr,
                                all_tids[thread_index], cpu, group_fd, 0);
 
-               if (fd[i][counter][thread_index] < 0) {
+               if (FD(evsel, i, thread_index) < 0) {
                        int err = errno;
 
                        if (err == EPERM || err == EACCES)
                        }
                        printf("\n");
                        error("sys_perf_event_open() syscall returned with %d (%s).  /bin/dmesg may provide additional information.\n",
-                                       fd[i][counter][thread_index], strerror(err));
+                                       FD(evsel, i, thread_index), strerror(err));
                        die("No CONFIG_PERF_EVENTS=y kernel support configured?\n");
                        exit(-1);
                }
-               assert(fd[i][counter][thread_index] >= 0);
-               fcntl(fd[i][counter][thread_index], F_SETFL, O_NONBLOCK);
+               assert(FD(evsel, i, thread_index) >= 0);
+               fcntl(FD(evsel, i, thread_index), F_SETFL, O_NONBLOCK);
 
                /*
                 * First counter acts as the group leader:
                 */
                if (group && group_fd == -1)
-                       group_fd = fd[i][counter][thread_index];
+                       group_fd = FD(evsel, i, thread_index);
 
-               event_array[nr_poll].fd = fd[i][counter][thread_index];
+               event_array[nr_poll].fd = FD(evsel, i, thread_index);
                event_array[nr_poll].events = POLLIN;
                nr_poll++;
 
-               mmap_array[i][counter][thread_index].counter = counter;
-               mmap_array[i][counter][thread_index].prev = 0;
-               mmap_array[i][counter][thread_index].mask = mmap_pages*page_size - 1;
-               mmap_array[i][counter][thread_index].base = mmap(NULL, (mmap_pages+1)*page_size,
-                               PROT_READ, MAP_SHARED, fd[i][counter][thread_index], 0);
-               if (mmap_array[i][counter][thread_index].base == MAP_FAILED)
+               mm = xyarray__entry(mmap_array, i, thread_index);
+               mm->prev = 0;
+               mm->mask = mmap_pages*page_size - 1;
+               mm->base = mmap(NULL, (mmap_pages+1)*page_size,
+                               PROT_READ, MAP_SHARED, FD(evsel, i, thread_index), 0);
+               if (mm->base == MAP_FAILED)
                        die("failed to mmap with %d (%s)\n", errno, strerror(errno));
        }
 }
 static int __cmd_top(void)
 {
        pthread_t thread;
-       int i, counter;
-       int ret;
+       struct perf_evsel *counter;
+       int i, ret;
        /*
         * FIXME: perf_session__new should allow passing a O_MMAP, so that all this
         * mmap reading, etc is encapsulated in it. Use O_WRONLY for now.
 
        for (i = 0; i < nr_cpus; i++) {
                group_fd = -1;
-               for (counter = 0; counter < nr_counters; counter++)
+               list_for_each_entry(counter, &evsel_list, node)
                        start_counter(i, counter);
        }
 
 
 int cmd_top(int argc, const char **argv, const char *prefix __used)
 {
-       int counter;
-       int i,j;
+       struct perf_evsel *pos;
+       int status = -ENOMEM;
 
        page_size = sysconf(_SC_PAGE_SIZE);
 
                thread_num = 1;
        }
 
-       for (i = 0; i < MAX_NR_CPUS; i++) {
-               for (j = 0; j < MAX_COUNTERS; j++) {
-                       fd[i][j] = malloc(sizeof(int)*thread_num);
-                       mmap_array[i][j] = zalloc(
-                               sizeof(struct mmap_data)*thread_num);
-                       if (!fd[i][j] || !mmap_array[i][j])
-                               return -ENOMEM;
-               }
-       }
        event_array = malloc(
                sizeof(struct pollfd)*MAX_NR_CPUS*MAX_COUNTERS*thread_num);
        if (!event_array)
                cpu_list = NULL;
        }
 
-       if (!nr_counters)
-               nr_counters = 1;
-
-       symbol_conf.priv_size = (sizeof(struct sym_entry) +
-                                (nr_counters + 1) * sizeof(unsigned long));
-
-       symbol_conf.try_vmlinux_path = (symbol_conf.vmlinux_name == NULL);
-       if (symbol__init() < 0)
-               return -1;
+       if (!nr_counters && perf_evsel_list__create_default() < 0) {
+               pr_err("Not enough memory for event selector list\n");
+               return -ENOMEM;
+       }
 
        if (delay_secs < 1)
                delay_secs = 1;
                exit(EXIT_FAILURE);
        }
 
-       /*
-        * Fill in the ones not specifically initialized via -c:
-        */
-       for (counter = 0; counter < nr_counters; counter++) {
-               if (attrs[counter].sample_period)
-                       continue;
-
-               attrs[counter].sample_period = default_interval;
-       }
-
        if (target_tid != -1)
                nr_cpus = 1;
        else
        if (nr_cpus < 1)
                usage_with_options(top_usage, options);
 
+       list_for_each_entry(pos, &evsel_list, node) {
+               if (perf_evsel__alloc_mmap_per_thread(pos, nr_cpus, thread_num) < 0 ||
+                   perf_evsel__alloc_fd(pos, nr_cpus, thread_num) < 0)
+                       goto out_free_fd;
+               /*
+                * Fill in the ones not specifically initialized via -c:
+                */
+               if (pos->attr.sample_period)
+                       continue;
+
+               pos->attr.sample_period = default_interval;
+       }
+
+       symbol_conf.priv_size = (sizeof(struct sym_entry) +
+                                (nr_counters + 1) * sizeof(unsigned long));
+
+       symbol_conf.try_vmlinux_path = (symbol_conf.vmlinux_name == NULL);
+       if (symbol__init() < 0)
+               return -1;
+
        get_term_dimensions(&winsize);
        if (print_entries == 0) {
                update_print_entries(&winsize);
                signal(SIGWINCH, sig_winch_handler);
        }
 
-       return __cmd_top();
+       status = __cmd_top();
+out_free_fd:
+       list_for_each_entry(pos, &evsel_list, node) {
+               perf_evsel__free_fd(pos);
+               perf_evsel__free_mmap(pos);
+       }
+
+       return status;
 }
 
--- /dev/null
+#include "evsel.h"
+#include "util.h"
+
+struct perf_evsel *perf_evsel__new(u32 type, u64 config, int idx)
+{
+       struct perf_evsel *evsel = zalloc(sizeof(*evsel));
+
+       if (evsel != NULL) {
+               evsel->idx         = idx;
+               evsel->attr.type   = type;
+               evsel->attr.config = config;
+               INIT_LIST_HEAD(&evsel->node);
+       }
+
+       return evsel;
+}
+
+int perf_evsel__alloc_fd(struct perf_evsel *evsel, int ncpus, int nthreads)
+{
+       evsel->fd = xyarray__new(ncpus, nthreads, sizeof(int));
+       return evsel->fd != NULL ? 0 : -ENOMEM;
+}
+
+void perf_evsel__free_fd(struct perf_evsel *evsel)
+{
+       xyarray__delete(evsel->fd);
+       evsel->fd = NULL;
+}
+
+void perf_evsel__delete(struct perf_evsel *evsel)
+{
+       assert(list_empty(&evsel->node));
+       xyarray__delete(evsel->fd);
+       free(evsel);
+}
 
--- /dev/null
+#ifndef __PERF_EVSEL_H
+#define __PERF_EVSEL_H 1
+
+#include <linux/list.h>
+#include <linux/perf_event.h>
+#include "types.h"
+#include "xyarray.h"
+
+struct perf_evsel {
+       struct list_head        node;
+       struct perf_event_attr  attr;
+       char                    *filter;
+       struct xyarray          *fd;
+       int                     idx;
+       void                    *priv;
+};
+
+struct perf_evsel *perf_evsel__new(u32 type, u64 config, int idx);
+void perf_evsel__delete(struct perf_evsel *evsel);
+
+int perf_evsel__alloc_fd(struct perf_evsel *evsel, int ncpus, int nthreads);
+void perf_evsel__free_fd(struct perf_evsel *evsel);
+
+#endif /* __PERF_EVSEL_H */
 
 
                /* Write trace info */
                trace_sec->offset = lseek(fd, 0, SEEK_CUR);
-               read_tracing_data(fd, attrs, nr_counters);
+               read_tracing_data(fd, &evsel_list);
                trace_sec->size = lseek(fd, 0, SEEK_CUR) - trace_sec->offset;
        }
 
        return 0;
 }
 
-int event__synthesize_tracing_data(int fd, struct perf_event_attr *pattrs,
-                                  int nb_events,
+int event__synthesize_tracing_data(int fd, struct list_head *pattrs,
                                   event__handler_t process,
                                   struct perf_session *session __unused)
 {
        memset(&ev, 0, sizeof(ev));
 
        ev.tracing_data.header.type = PERF_RECORD_HEADER_TRACING_DATA;
-       size = read_tracing_data_size(fd, pattrs, nb_events);
+       size = read_tracing_data_size(fd, pattrs);
        if (size <= 0)
                return size;
        aligned_size = ALIGN(size, sizeof(u64));
 
        process(&ev, NULL, session);
 
-       err = read_tracing_data(fd, pattrs, nb_events);
+       err = read_tracing_data(fd, pattrs);
        write_padded(fd, NULL, 0, padding);
 
        return aligned_size;
 
 int event__process_event_type(event_t *self,
                              struct perf_session *session);
 
-int event__synthesize_tracing_data(int fd, struct perf_event_attr *pattrs,
-                                  int nb_events,
+int event__synthesize_tracing_data(int fd, struct list_head *pattrs,
                                   event__handler_t process,
                                   struct perf_session *session);
 int event__process_tracing_data(event_t *self,
 
 #include "../../../include/linux/hw_breakpoint.h"
 #include "util.h"
 #include "../perf.h"
+#include "evsel.h"
 #include "parse-options.h"
 #include "parse-events.h"
 #include "exec_cmd.h"
 
 int                            nr_counters;
 
-struct perf_event_attr         attrs[MAX_COUNTERS];
-char                           *filters[MAX_COUNTERS];
+LIST_HEAD(evsel_list);
 
 struct event_symbol {
        u8              type;
        return name;
 }
 
-const char *event_name(int counter)
+const char *event_name(struct perf_evsel *evsel)
 {
-       u64 config = attrs[counter].config;
-       int type = attrs[counter].type;
+       u64 config = evsel->attr.config;
+       int type = evsel->attr.type;
 
        return __event_name(type, config);
 }
                        return -1;
 
        for (;;) {
-               if (nr_counters == MAX_COUNTERS)
-                       return -1;
-
                memset(&attr, 0, sizeof(attr));
                ret = parse_event_symbols(&str, &attr);
                if (ret == EVT_FAILED)
                        return -1;
 
                if (ret != EVT_HANDLED_ALL) {
-                       attrs[nr_counters] = attr;
-                       nr_counters++;
+                       struct perf_evsel *evsel;
+                       evsel = perf_evsel__new(attr.type, attr.config,
+                                               nr_counters);
+                       if (evsel == NULL)
+                               return -1;
+                       list_add_tail(&evsel->node, &evsel_list);
+                       ++nr_counters;
                }
 
                if (*str == 0)
 int parse_filter(const struct option *opt __used, const char *str,
                 int unset __used)
 {
-       int i = nr_counters - 1;
-       int len = strlen(str);
+       struct perf_evsel *last = NULL;
 
-       if (i < 0 || attrs[i].type != PERF_TYPE_TRACEPOINT) {
+       if (!list_empty(&evsel_list))
+               last = list_entry(evsel_list.prev, struct perf_evsel, node);
+
+       if (last == NULL || last->attr.type != PERF_TYPE_TRACEPOINT) {
                fprintf(stderr,
                        "-F option should follow a -e tracepoint option\n");
                return -1;
        }
 
-       filters[i] = malloc(len + 1);
-       if (!filters[i]) {
+       last->filter = strdup(str);
+       if (last->filter == NULL) {
                fprintf(stderr, "not enough memory to hold filter string\n");
                return -1;
        }
-       strcpy(filters[i], str);
 
        return 0;
 }
 
        exit(129);
 }
+
+int perf_evsel_list__create_default(void)
+{
+       struct perf_evsel *evsel = perf_evsel__new(PERF_TYPE_HARDWARE,
+                                                  PERF_COUNT_HW_CPU_CYCLES, 0);
+       if (evsel == NULL)
+               return -ENOMEM;
+
+       list_add(&evsel->node, &evsel_list);
+       ++nr_counters;
+       return 0;
+}
 
  * Parse symbolic events/counts passed in as options:
  */
 
+#include <linux/perf_event.h>
+
+struct list_head;
+struct perf_evsel;
+
+extern struct list_head evsel_list;
+
+int perf_evsel_list__create_default(void);
+
 struct option;
 
 struct tracepoint_path {
 };
 
 extern struct tracepoint_path *tracepoint_id_to_path(u64 config);
-extern bool have_tracepoints(struct perf_event_attr *pattrs, int nb_events);
+extern bool have_tracepoints(struct list_head *evsel_list);
 
 extern int                     nr_counters;
 
-extern struct perf_event_attr attrs[MAX_COUNTERS];
-extern char *filters[MAX_COUNTERS];
-
-extern const char *event_name(int ctr);
+const char *event_name(struct perf_evsel *event);
 extern const char *__event_name(int type, u64 config);
 
 extern int parse_events(const struct option *opt, const char *str, int unset);
 extern char debugfs_path[];
 extern int valid_debugfs_mount(const char *debugfs);
 
-
 #endif /* __PERF_PARSE_EVENTS_H */
 
 #include <ctype.h>
 #include <errno.h>
 #include <stdbool.h>
+#include <linux/list.h>
 #include <linux/kernel.h>
 
 #include "../perf.h"
 #include "trace-event.h"
 #include "debugfs.h"
+#include "evsel.h"
 
 #define VERSION "0.5"
 
 }
 
 static struct tracepoint_path *
-get_tracepoints_path(struct perf_event_attr *pattrs, int nb_events)
+get_tracepoints_path(struct list_head *pattrs)
 {
        struct tracepoint_path path, *ppath = &path;
-       int i, nr_tracepoints = 0;
+       struct perf_evsel *pos;
+       int nr_tracepoints = 0;
 
-       for (i = 0; i < nb_events; i++) {
-               if (pattrs[i].type != PERF_TYPE_TRACEPOINT)
+       list_for_each_entry(pos, pattrs, node) {
+               if (pos->attr.type != PERF_TYPE_TRACEPOINT)
                        continue;
                ++nr_tracepoints;
-               ppath->next = tracepoint_id_to_path(pattrs[i].config);
+               ppath->next = tracepoint_id_to_path(pos->attr.config);
                if (!ppath->next)
                        die("%s\n", "No memory to alloc tracepoints list");
                ppath = ppath->next;
        return nr_tracepoints > 0 ? path.next : NULL;
 }
 
-bool have_tracepoints(struct perf_event_attr *pattrs, int nb_events)
+bool have_tracepoints(struct list_head *pattrs)
 {
-       int i;
+       struct perf_evsel *pos;
 
-       for (i = 0; i < nb_events; i++)
-               if (pattrs[i].type == PERF_TYPE_TRACEPOINT)
+       list_for_each_entry(pos, pattrs, node)
+               if (pos->attr.type == PERF_TYPE_TRACEPOINT)
                        return true;
 
        return false;
 }
 
-int read_tracing_data(int fd, struct perf_event_attr *pattrs, int nb_events)
+int read_tracing_data(int fd, struct list_head *pattrs)
 {
        char buf[BUFSIZ];
-       struct tracepoint_path *tps = get_tracepoints_path(pattrs, nb_events);
+       struct tracepoint_path *tps = get_tracepoints_path(pattrs);
 
        /*
         * What? No tracepoints? No sense writing anything here, bail out.
        return 0;
 }
 
-ssize_t read_tracing_data_size(int fd, struct perf_event_attr *pattrs,
-                              int nb_events)
+ssize_t read_tracing_data_size(int fd, struct list_head *pattrs)
 {
        ssize_t size;
        int err = 0;
 
        calc_data_size = 1;
-       err = read_tracing_data(fd, pattrs, nb_events);
+       err = read_tracing_data(fd, pattrs);
        size = calc_data_size - 1;
        calc_data_size = 0;
 
 
 void *raw_field_ptr(struct event *event, const char *name, void *data);
 unsigned long long eval_flag(const char *flag);
 
-int read_tracing_data(int fd, struct perf_event_attr *pattrs, int nb_events);
-ssize_t read_tracing_data_size(int fd, struct perf_event_attr *pattrs,
-                              int nb_events);
+int read_tracing_data(int fd, struct list_head *pattrs);
+ssize_t read_tracing_data_size(int fd, struct list_head *pattrs);
 
 /* taken from kernel/trace/trace.h */
 enum trace_flag_type {
 
--- /dev/null
+#include "xyarray.h"
+#include "util.h"
+
+struct xyarray *xyarray__new(int xlen, int ylen, size_t entry_size)
+{
+       size_t row_size = ylen * entry_size;
+       struct xyarray *xy = zalloc(sizeof(*xy) + xlen * row_size);
+
+       if (xy != NULL) {
+               xy->entry_size = entry_size;
+               xy->row_size   = row_size;
+       }
+
+       return xy;
+}
+
+void xyarray__delete(struct xyarray *xy)
+{
+       free(xy);
+}
 
--- /dev/null
+#ifndef _PERF_XYARRAY_H_
+#define _PERF_XYARRAY_H_ 1
+
+#include <sys/types.h>
+
+struct xyarray {
+       size_t row_size;
+       size_t entry_size;
+       char contents[];
+};
+
+struct xyarray *xyarray__new(int xlen, int ylen, size_t entry_size);
+void xyarray__delete(struct xyarray *xy);
+
+static inline void *xyarray__entry(struct xyarray *xy, int x, int y)
+{
+       return &xy->contents[x * xy->row_size + y * xy->entry_size];
+}
+
+#endif /* _PERF_XYARRAY_H_ */