perf report: Allow limiting the number of entries to print in callchains

Works by adding a third parameter to the '-g' argument, after the graph
type and minimum percentage, for example:

[root@doppio linux-2.6-tip]# perf report -g fractal,0.5,2

Will show only the first two symbols where at least 0.5% of the samples
took place.

All the other symbols that don't fall outside these constraints will be
put together in the last entry, prefixed with "[...]" and the total
percentage for them.

Suggested-by: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index 5e2f47f..642a6d8 100644 (file)
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -343,7 +343,7 @@ static int
 parse_callchain_opt(const struct option *opt __used, const char *arg,
                    int unset)
 {
-       char *tok;
+       char *tok, *tok2;
        char *endptr;
 
        /*
@@ -388,10 +388,13 @@ parse_callchain_opt(const struct option *opt __used, const char *arg,
        if (!tok)
                goto setup;
 
+       tok2 = strtok(NULL, ",");
        callchain_param.min_percent = strtod(tok, &endptr);
        if (tok == endptr)
                return -1;
 
+       if (tok2)
+               callchain_param.print_limit = strtod(tok2, &endptr);
 setup:
        if (register_callchain_param(&callchain_param) < 0) {
                fprintf(stderr, "Can't register callchain params\n");

diff --git a/tools/perf/util/callchain.h b/tools/perf/util/callchain.h
index 0f4da09..1cba1f5 100644 (file)
--- a/tools/perf/util/callchain.h
+++ b/tools/perf/util/callchain.h
@@ -34,6 +34,7 @@ typedef void (*sort_chain_func_t)(struct rb_root *, struct callchain_node *,
 
 struct callchain_param {
        enum chain_mode         mode;
+       u32                     print_limit;
        double                  min_percent;
        sort_chain_func_t       sort;
 };

diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c
index e0c8a72..0f154a5 100644 (file)
--- a/tools/perf/util/hist.c
+++ b/tools/perf/util/hist.c
@@ -333,6 +333,7 @@ static size_t __callchain__fprintf_graph(FILE *fp, struct callchain_node *self,
        u64 remaining;
        size_t ret = 0;
        int i;
+       uint entries_printed = 0;
 
        if (callchain_param.mode == CHAIN_GRAPH_REL)
                new_total = self->children_hit;
@@ -379,6 +380,8 @@ static size_t __callchain__fprintf_graph(FILE *fp, struct callchain_node *self,
                                                  new_depth_mask | (1 << depth),
                                                  left_margin);
                node = next;
+               if (++entries_printed == callchain_param.print_limit)
+                       break;
        }
 
        if (callchain_param.mode == CHAIN_GRAPH_REL &&
@@ -404,6 +407,7 @@ static size_t callchain__fprintf_graph(FILE *fp, struct callchain_node *self,
        bool printed = false;
        int i = 0;
        int ret = 0;
+       u32 entries_printed = 0;
 
        list_for_each_entry(chain, &self->val, list) {
                if (!i++ && sort__first_dimension == SORT_SYM)
@@ -424,6 +428,9 @@ static size_t callchain__fprintf_graph(FILE *fp, struct callchain_node *self,
                        ret += fprintf(fp, " %s\n", chain->ms.sym->name);
                else
                        ret += fprintf(fp, " %p\n", (void *)(long)chain->ip);
+
+               if (++entries_printed == callchain_param.print_limit)
+                       break;
        }
 
        ret += __callchain__fprintf_graph(fp, self, total_samples, 1, 1, left_margin);
@@ -462,6 +469,7 @@ static size_t hist_entry_callchain__fprintf(FILE *fp, struct hist_entry *self,
        struct rb_node *rb_node;
        struct callchain_node *chain;
        size_t ret = 0;
+       u32 entries_printed = 0;
 
        rb_node = rb_first(&self->sorted_chain);
        while (rb_node) {
@@ -484,6 +492,8 @@ static size_t hist_entry_callchain__fprintf(FILE *fp, struct hist_entry *self,
                        break;
                }
                ret += fprintf(fp, "\n");
+               if (++entries_printed == callchain_param.print_limit)
+                       break;
                rb_node = rb_next(rb_node);
        }