perf report: Calculate the average cycles of iterations

The branch history code has a loop detection function. With this, we can
get the number of iterations by calculating the removed loops.

While it would be nice for knowing the average cycles of iterations.
This patch adds up the cycles in branch entries of removed loops and
save the result to the next branch entry (e.g. branch entry A).

Finally it will display the iteration number and average cycles at the
"from" of branch entry A.

For example:
perf record -g -j any,save_type ./div
perf report --branch-history --no-children --stdio

--22.63%--main div.c:42 (RET CROSS_2M)
          compute_flag div.c:28 (cycles:2 iter:173115 avg_cycles:2)
          |
           --10.73%--compute_flag div.c:27 (RET CROSS_2M)
                     rand rand.c:28 (cycles:1)
                     rand rand.c:28 (RET CROSS_2M)
                     __random random.c:298 (cycles:1)
                     __random random.c:297 (COND_BWD CROSS_2M)
                     __random random.c:295 (cycles:1)
                     __random random.c:295 (COND_BWD CROSS_2M)
                     __random random.c:295 (cycles:1)
                     __random random.c:295 (RET CROSS_2M)

Signed-off-by: Yao Jin <yao.jin@linux.intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1502111115-18305-1-git-send-email-yao.jin@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/ui/browsers/hists.c b/tools/perf/ui/browsers/hists.c
index f4bc2462bc2ce5587721de5441d935223d615348..13dfb0a0bdeb440776b506fd413be307e716e0bf 100644 (file)
--- a/tools/perf/ui/browsers/hists.c
+++ b/tools/perf/ui/browsers/hists.c
@@ -931,12 +931,8 @@ static int hist_browser__show_callchain_list(struct hist_browser *browser,
                                       browser->show_dso);
 
        if (symbol_conf.show_branchflag_count) {
-               if (need_percent)
-                       callchain_list_counts__printf_value(node, chain, NULL,
-                                                           buf, sizeof(buf));
-               else
-                       callchain_list_counts__printf_value(NULL, chain, NULL,
-                                                           buf, sizeof(buf));
+               callchain_list_counts__printf_value(chain, NULL,
+                                                   buf, sizeof(buf));
 
                if (asprintf(&alloc_str2, "%s%s", str, buf) < 0)
                        str = "Not enough memory!";

diff --git a/tools/perf/ui/stdio/hist.c b/tools/perf/ui/stdio/hist.c
index 5c95b8301c670f96f72e1dcbaf4b7ef1142328d9..8bdb7a50018128feb120064bdf76e93572696372 100644 (file)
--- a/tools/perf/ui/stdio/hist.c
+++ b/tools/perf/ui/stdio/hist.c
@@ -124,12 +124,8 @@ static size_t ipchain__fprintf_graph(FILE *fp, struct callchain_node *node,
        str = callchain_list__sym_name(chain, bf, sizeof(bf), false);
 
        if (symbol_conf.show_branchflag_count) {
-               if (!period)
-                       callchain_list_counts__printf_value(node, chain, NULL,
-                                                           buf, sizeof(buf));
-               else
-                       callchain_list_counts__printf_value(NULL, chain, NULL,
-                                                           buf, sizeof(buf));
+               callchain_list_counts__printf_value(chain, NULL,
+                                                   buf, sizeof(buf));
 
                if (asprintf(&alloc_str, "%s%s", str, buf) < 0)
                        str = "Not enough memory!";
@@ -313,7 +309,7 @@ static size_t callchain__fprintf_graph(FILE *fp, struct rb_root *root,
 
                        if (symbol_conf.show_branchflag_count)
                                ret += callchain_list_counts__printf_value(
-                                               NULL, chain, fp, NULL, 0);
+                                               chain, fp, NULL, 0);
                        ret += fprintf(fp, "\n");
 
                        if (++entries_printed == callchain_param.print_limit)

diff --git a/tools/perf/util/callchain.c b/tools/perf/util/callchain.c
index f320b0777e0d8d5b08dd01aaeb4fd5a657c282fa..510b513e0f01fe96e110b9eab45db527b8c86104 100644 (file)
--- a/tools/perf/util/callchain.c
+++ b/tools/perf/util/callchain.c
@@ -588,7 +588,7 @@ fill_node(struct callchain_node *node, struct callchain_cursor *cursor)
                                call->cycles_count =
                                        cursor_node->branch_flags.cycles;
                                call->iter_count = cursor_node->nr_loop_iter;
-                               call->samples_count = cursor_node->samples;
+                               call->iter_cycles = cursor_node->iter_cycles;
                        }
                }
 
@@ -722,7 +722,7 @@ static enum match_result match_chain(struct callchain_cursor_node *node,
                                cnode->cycles_count +=
                                        node->branch_flags.cycles;
                                cnode->iter_count += node->nr_loop_iter;
-                               cnode->samples_count += node->samples;
+                               cnode->iter_cycles += node->iter_cycles;
                        }
                }
 
@@ -998,7 +998,7 @@ int callchain_merge(struct callchain_cursor *cursor,
 int callchain_cursor_append(struct callchain_cursor *cursor,
                            u64 ip, struct map *map, struct symbol *sym,
                            bool branch, struct branch_flags *flags,
-                           int nr_loop_iter, int samples, u64 branch_from)
+                           int nr_loop_iter, u64 iter_cycles, u64 branch_from)
 {
        struct callchain_cursor_node *node = *cursor->last;
 
@@ -1016,7 +1016,7 @@ int callchain_cursor_append(struct callchain_cursor *cursor,
        node->sym = sym;
        node->branch = branch;
        node->nr_loop_iter = nr_loop_iter;
-       node->samples = samples;
+       node->iter_cycles = iter_cycles;
 
        if (flags)
                memcpy(&node->branch_flags, flags,
@@ -1306,7 +1306,7 @@ static int branch_to_str(char *bf, int bfsize,
 static int branch_from_str(char *bf, int bfsize,
                           u64 branch_count,
                           u64 cycles_count, u64 iter_count,
-                          u64 samples_count)
+                          u64 iter_cycles)
 {
        int printed = 0, i = 0;
        u64 cycles;
@@ -1318,9 +1318,13 @@ static int branch_from_str(char *bf, int bfsize,
                                bf + printed, bfsize - printed);
        }
 
-       if (iter_count && samples_count) {
-               printed += count_pri64_printf(i++, "iterations",
-                               iter_count / samples_count,
+       if (iter_count) {
+               printed += count_pri64_printf(i++, "iter",
+                               iter_count,
+                               bf + printed, bfsize - printed);
+
+               printed += count_pri64_printf(i++, "avg_cycles",
+                               iter_cycles / iter_count,
                                bf + printed, bfsize - printed);
        }
 
@@ -1333,7 +1337,7 @@ static int branch_from_str(char *bf, int bfsize,
 static int counts_str_build(char *bf, int bfsize,
                             u64 branch_count, u64 predicted_count,
                             u64 abort_count, u64 cycles_count,
-                            u64 iter_count, u64 samples_count,
+                            u64 iter_count, u64 iter_cycles,
                             struct branch_type_stat *brtype_stat)
 {
        int printed;
@@ -1346,7 +1350,7 @@ static int counts_str_build(char *bf, int bfsize,
                                predicted_count, abort_count, brtype_stat);
        } else {
                printed = branch_from_str(bf, bfsize, branch_count,
-                               cycles_count, iter_count, samples_count);
+                               cycles_count, iter_count, iter_cycles);
        }
 
        if (!printed)
@@ -1358,14 +1362,14 @@ static int counts_str_build(char *bf, int bfsize,
 static int callchain_counts_printf(FILE *fp, char *bf, int bfsize,
                                   u64 branch_count, u64 predicted_count,
                                   u64 abort_count, u64 cycles_count,
-                                  u64 iter_count, u64 samples_count,
+                                  u64 iter_count, u64 iter_cycles,
                                   struct branch_type_stat *brtype_stat)
 {
        char str[256];
 
        counts_str_build(str, sizeof(str), branch_count,
                         predicted_count, abort_count, cycles_count,
-                        iter_count, samples_count, brtype_stat);
+                        iter_count, iter_cycles, brtype_stat);
 
        if (fp)
                return fprintf(fp, "%s", str);
@@ -1373,31 +1377,23 @@ static int callchain_counts_printf(FILE *fp, char *bf, int bfsize,
        return scnprintf(bf, bfsize, "%s", str);
 }
 
-int callchain_list_counts__printf_value(struct callchain_node *node,
-                                       struct callchain_list *clist,
+int callchain_list_counts__printf_value(struct callchain_list *clist,
                                        FILE *fp, char *bf, int bfsize)
 {
        u64 branch_count, predicted_count;
        u64 abort_count, cycles_count;
-       u64 iter_count = 0, samples_count = 0;
+       u64 iter_count, iter_cycles;
 
        branch_count = clist->branch_count;
        predicted_count = clist->predicted_count;
        abort_count = clist->abort_count;
        cycles_count = clist->cycles_count;
-
-       if (node) {
-               struct callchain_list *call;
-
-               list_for_each_entry(call, &node->val, list) {
-                       iter_count += call->iter_count;
-                       samples_count += call->samples_count;
-               }
-       }
+       iter_count = clist->iter_count;
+       iter_cycles = clist->iter_cycles;
 
        return callchain_counts_printf(fp, bf, bfsize, branch_count,
                                       predicted_count, abort_count,
-                                      cycles_count, iter_count, samples_count,
+                                      cycles_count, iter_count, iter_cycles,
                                       &clist->brtype_stat);
 }
 
@@ -1523,7 +1519,8 @@ int callchain_cursor__copy(struct callchain_cursor *dst,
 
                rc = callchain_cursor_append(dst, node->ip, node->map, node->sym,
                                             node->branch, &node->branch_flags,
-                                            node->nr_loop_iter, node->samples,
+                                            node->nr_loop_iter,
+                                            node->iter_cycles,
                                             node->branch_from);
                if (rc)
                        break;

diff --git a/tools/perf/util/callchain.h b/tools/perf/util/callchain.h
index 97738201464adc529b31e07a72e8f88bc0022492..1ed6fc61d0a5906fe8e4e9e344c8c9fa9a925735 100644 (file)
--- a/tools/perf/util/callchain.h
+++ b/tools/perf/util/callchain.h
@@ -119,7 +119,7 @@ struct callchain_list {
        u64                     abort_count;
        u64                     cycles_count;
        u64                     iter_count;
-       u64                     samples_count;
+       u64                     iter_cycles;
        struct branch_type_stat brtype_stat;
        char                   *srcline;
        struct list_head        list;
@@ -139,7 +139,7 @@ struct callchain_cursor_node {
        struct branch_flags             branch_flags;
        u64                             branch_from;
        int                             nr_loop_iter;
-       int                             samples;
+       u64                             iter_cycles;
        struct callchain_cursor_node    *next;
 };
 
@@ -201,7 +201,7 @@ static inline void callchain_cursor_reset(struct callchain_cursor *cursor)
 int callchain_cursor_append(struct callchain_cursor *cursor, u64 ip,
                            struct map *map, struct symbol *sym,
                            bool branch, struct branch_flags *flags,
-                           int nr_loop_iter, int samples, u64 branch_from);
+                           int nr_loop_iter, u64 iter_cycles, u64 branch_from);
 
 /* Close a cursor writing session. Initialize for the reader */
 static inline void callchain_cursor_commit(struct callchain_cursor *cursor)
@@ -282,8 +282,7 @@ char *callchain_node__scnprintf_value(struct callchain_node *node,
 int callchain_node__fprintf_value(struct callchain_node *node,
                                  FILE *fp, u64 total);
 
-int callchain_list_counts__printf_value(struct callchain_node *node,
-                                       struct callchain_list *clist,
+int callchain_list_counts__printf_value(struct callchain_list *clist,
                                        FILE *fp, char *bf, int bfsize);
 
 void free_callchain(struct callchain_root *root);

diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index 5c8eacaca4f4f3bce32db13ee2f86cf55a90634a..9eaa95302c864f85be22dcf121abeae2ef7ae129 100644 (file)
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -1675,6 +1675,11 @@ struct mem_info *sample__resolve_mem(struct perf_sample *sample,
        return mi;
 }
 
+struct iterations {
+       int nr_loop_iter;
+       u64 cycles;
+};
+
 static int add_callchain_ip(struct thread *thread,
                            struct callchain_cursor *cursor,
                            struct symbol **parent,
@@ -1683,11 +1688,12 @@ static int add_callchain_ip(struct thread *thread,
                            u64 ip,
                            bool branch,
                            struct branch_flags *flags,
-                           int nr_loop_iter,
-                           int samples,
+                           struct iterations *iter,
                            u64 branch_from)
 {
        struct addr_location al;
+       int nr_loop_iter = 0;
+       u64 iter_cycles = 0;
 
        al.filtered = 0;
        al.sym = NULL;
@@ -1737,9 +1743,15 @@ static int add_callchain_ip(struct thread *thread,
 
        if (symbol_conf.hide_unresolved && al.sym == NULL)
                return 0;
+
+       if (iter) {
+               nr_loop_iter = iter->nr_loop_iter;
+               iter_cycles = iter->cycles;
+       }
+
        return callchain_cursor_append(cursor, al.addr, al.map, al.sym,
-                                      branch, flags, nr_loop_iter, samples,
-                                      branch_from);
+                                      branch, flags, nr_loop_iter,
+                                      iter_cycles, branch_from);
 }
 
 struct branch_info *sample__resolve_bstack(struct perf_sample *sample,
@@ -1760,6 +1772,18 @@ struct branch_info *sample__resolve_bstack(struct perf_sample *sample,
        return bi;
 }
 
+static void save_iterations(struct iterations *iter,
+                           struct branch_entry *be, int nr)
+{
+       int i;
+
+       iter->nr_loop_iter = nr;
+       iter->cycles = 0;
+
+       for (i = 0; i < nr; i++)
+               iter->cycles += be[i].flags.cycles;
+}
+
 #define CHASHSZ 127
 #define CHASHBITS 7
 #define NO_ENTRY 0xff
@@ -1767,7 +1791,8 @@ struct branch_info *sample__resolve_bstack(struct perf_sample *sample,
 #define PERF_MAX_BRANCH_DEPTH 127
 
 /* Remove loops. */
-static int remove_loops(struct branch_entry *l, int nr)
+static int remove_loops(struct branch_entry *l, int nr,
+                       struct iterations *iter)
 {
        int i, j, off;
        unsigned char chash[CHASHSZ];
@@ -1792,8 +1817,18 @@ static int remove_loops(struct branch_entry *l, int nr)
                                        break;
                                }
                        if (is_loop) {
-                               memmove(l + i, l + i + off,
-                                       (nr - (i + off)) * sizeof(*l));
+                               j = nr - (i + off);
+                               if (j > 0) {
+                                       save_iterations(iter + i + off,
+                                               l + i, off);
+
+                                       memmove(iter + i, iter + i + off,
+                                               j * sizeof(*iter));
+
+                                       memmove(l + i, l + i + off,
+                                               j * sizeof(*l));
+                               }
+
                                nr -= off;
                        }
                }
@@ -1883,7 +1918,7 @@ static int resolve_lbr_callchain_sample(struct thread *thread,
 
                        err = add_callchain_ip(thread, cursor, parent,
                                               root_al, &cpumode, ip,
-                                              branch, flags, 0, 0,
+                                              branch, flags, NULL,
                                               branch_from);
                        if (err)
                                return (err < 0) ? err : 0;
@@ -1909,7 +1944,6 @@ static int thread__resolve_callchain_sample(struct thread *thread,
        int i, j, err, nr_entries;
        int skip_idx = -1;
        int first_call = 0;
-       int nr_loop_iter;
 
        if (chain)
                chain_nr = chain->nr;
@@ -1942,6 +1976,7 @@ static int thread__resolve_callchain_sample(struct thread *thread,
        if (branch && callchain_param.branch_callstack) {
                int nr = min(max_stack, (int)branch->nr);
                struct branch_entry be[nr];
+               struct iterations iter[nr];
 
                if (branch->nr > PERF_MAX_BRANCH_DEPTH) {
                        pr_warning("corrupted branch chain. skipping...\n");
@@ -1972,38 +2007,21 @@ static int thread__resolve_callchain_sample(struct thread *thread,
                                be[i] = branch->entries[branch->nr - i - 1];
                }
 
-               nr_loop_iter = nr;
-               nr = remove_loops(be, nr);
-
-               /*
-                * Get the number of iterations.
-                * It's only approximation, but good enough in practice.
-                */
-               if (nr_loop_iter > nr)
-                       nr_loop_iter = nr_loop_iter - nr + 1;
-               else
-                       nr_loop_iter = 0;
+               memset(iter, 0, sizeof(struct iterations) * nr);
+               nr = remove_loops(be, nr, iter);
 
                for (i = 0; i < nr; i++) {
-                       if (i == nr - 1)
-                               err = add_callchain_ip(thread, cursor, parent,
-                                                      root_al,
-                                                      NULL, be[i].to,
-                                                      true, &be[i].flags,
-                                                      nr_loop_iter, 1,
-                                                      be[i].from);
-                       else
-                               err = add_callchain_ip(thread, cursor, parent,
-                                                      root_al,
-                                                      NULL, be[i].to,
-                                                      true, &be[i].flags,
-                                                      0, 0, be[i].from);
+                       err = add_callchain_ip(thread, cursor, parent,
+                                              root_al,
+                                              NULL, be[i].to,
+                                              true, &be[i].flags,
+                                              NULL, be[i].from);
 
                        if (!err)
                                err = add_callchain_ip(thread, cursor, parent, root_al,
                                                       NULL, be[i].from,
                                                       true, &be[i].flags,
-                                                      0, 0, 0);
+                                                      &iter[i], 0);
                        if (err == -EINVAL)
                                break;
                        if (err)
@@ -2037,7 +2055,7 @@ check_calls:
 
                err = add_callchain_ip(thread, cursor, parent,
                                       root_al, &cpumode, ip,
-                                      false, NULL, 0, 0, 0);
+                                      false, NULL, NULL, 0);
 
                if (err)
                        return (err < 0) ? err : 0;