struct hist_entry       he;
 };
 
+static char const *coalesce_default = "pid,tid,iaddr";
+
 struct perf_c2c {
        struct perf_tool        tool;
        struct c2c_hists        hists;
        int                     shared_clines;
 
        int                      display;
+
+       const char              *coalesce;
+       char                    *cl_sort;
+       char                    *cl_resort;
+       char                    *cl_output;
 };
 
 enum {
                if (!mi_dup)
                        goto free_mi;
 
-               c2c_hists = he__get_c2c_hists(he, "offset", 2);
+               c2c_hists = he__get_c2c_hists(he, c2c.cl_sort, 2);
                if (!c2c_hists)
                        goto free_mi_dup;
 
        c2c_hists = c2c_he->hists;
 
        if (display && c2c_hists) {
-               c2c_hists__reinit(c2c_hists,
-                       "percent_rmt_hitm,"
-                       "percent_lcl_hitm,"
-                       "percent_stores_l1hit,"
-                       "percent_stores_l1miss,"
-                       "offset,"
-                       "pid,"
-                       "tid,"
-                       "mean_rmt,"
-                       "mean_lcl,"
-                       "mean_load,"
-                       "cpucnt,"
-                       "symbol,"
-                       "dso,"
-                       "node",
-                       "offset,rmt_hitm,lcl_hitm");
+               c2c_hists__reinit(c2c_hists, c2c.cl_output, c2c.cl_resort);
 
                hists__collapse_resort(&c2c_hists->hists, NULL);
                hists__output_resort_cb(&c2c_hists->hists, NULL, filter_cb);
        }
        fprintf(out, "  Cachelines sort on                : %s HITMs\n",
                c2c.display == DISPLAY_LCL ? "Local" : "Remote");
+       fprintf(out, "  Cacheline data grouping           : %s\n", c2c.cl_sort);
 }
 
 static void perf_c2c__hists_fprintf(FILE *out, struct perf_session *session)
        return 0;
 }
 
+#define for_each_token(__tok, __buf, __sep, __tmp)             \
+       for (__tok = strtok_r(__buf, __sep, &__tmp); __tok;     \
+            __tok = strtok_r(NULL,  __sep, &__tmp))
+
+static int build_cl_output(char *cl_sort)
+{
+       char *tok, *tmp, *buf = strdup(cl_sort);
+       bool add_pid   = false;
+       bool add_tid   = false;
+       bool add_iaddr = false;
+       bool add_sym   = false;
+       bool add_dso   = false;
+       bool add_src   = false;
+
+       if (!buf)
+               return -ENOMEM;
+
+       for_each_token(tok, buf, ",", tmp) {
+               if (!strcmp(tok, "tid")) {
+                       add_tid = true;
+               } else if (!strcmp(tok, "pid")) {
+                       add_pid = true;
+               } else if (!strcmp(tok, "iaddr")) {
+                       add_iaddr = true;
+                       add_sym   = true;
+                       add_dso   = true;
+                       add_src   = true;
+               } else if (!strcmp(tok, "dso")) {
+                       add_dso = true;
+               } else if (strcmp(tok, "offset")) {
+                       pr_err("unrecognized sort token: %s\n", tok);
+                       return -EINVAL;
+               }
+       }
+
+       if (asprintf(&c2c.cl_output,
+               "%s%s%s%s%s%s%s%s%s",
+               "percent_rmt_hitm,"
+               "percent_lcl_hitm,"
+               "percent_stores_l1hit,"
+               "percent_stores_l1miss,"
+               "offset,",
+               add_pid   ? "pid," : "",
+               add_tid   ? "tid," : "",
+               add_iaddr ? "iaddr," : "",
+               "mean_rmt,"
+               "mean_lcl,"
+               "mean_load,"
+               "cpucnt,",
+               add_sym ? "symbol," : "",
+               add_dso ? "dso," : "",
+               add_src ? "cl_srcline," : "",
+               "node") < 0)
+               return -ENOMEM;
+
+       c2c.show_src = add_src;
+
+       free(buf);
+       return 0;
+}
+
+static int setup_coalesce(const char *coalesce)
+{
+       const char *c = coalesce ?: coalesce_default;
+
+       if (asprintf(&c2c.cl_sort, "offset,%s", c) < 0)
+               return -ENOMEM;
+
+       if (build_cl_output(c2c.cl_sort))
+               return -1;
+
+       if (asprintf(&c2c.cl_resort, "offset,%s",
+                    c2c.display == DISPLAY_RMT ?
+                    "rmt_hitm,lcl_hitm" :
+                    "lcl_hitm,rmt_hitm") < 0)
+               return -ENOMEM;
+
+       pr_debug("coalesce sort   fields: %s\n", c2c.cl_sort);
+       pr_debug("coalesce resort fields: %s\n", c2c.cl_resort);
+       pr_debug("coalesce output fields: %s\n", c2c.cl_output);
+       return 0;
+}
+
 static int perf_c2c__report(int argc, const char **argv)
 {
        struct perf_session *session;
        };
        char callchain_default_opt[] = CALLCHAIN_DEFAULT_OPT;
        const char *display = NULL;
+       const char *coalesce = NULL;
        const struct option c2c_options[] = {
        OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
                   "file", "vmlinux pathname"),
                             callchain_help, &parse_callchain_opt,
                             callchain_default_opt),
        OPT_STRING('d', "display", &display, NULL, "lcl,rmt"),
+       OPT_STRING('c', "coalesce", &coalesce, "coalesce fields",
+                  "coalesce fields: pid,tid,iaddr,dso"),
        OPT_END()
        };
        int err = 0;
        if (err)
                goto out;
 
+       err = setup_coalesce(coalesce);
+       if (err) {
+               pr_debug("Failed to initialize hists\n");
+               goto out;
+       }
+
        err = c2c_hists__init(&c2c.hists, "dcacheline", 2);
        if (err) {
                pr_debug("Failed to initialize hists\n");