perf callchain: Start moving away from global per thread cursors

The recent perf_evsel__fprintf_callchain() move to evsel.c added several
new symbol requirements to the python binding, for instance:

  # perf test -v python
  16: Try 'import perf' in python, checking link problems      :
  --- start ---
  test child forked, pid 18030
  Traceback (most recent call last):
    File "<stdin>", line 1, in <module>
  ImportError: /tmp/build/perf/python/perf.so: undefined symbol:
  callchain_cursor
  test child finished with -1
  ---- end ----
  Try 'import perf' in python, checking link problems: FAILED!
  #

This would require linking against callchain.c to access to the global
callchain_cursor variables.

Since lots of functions already receive as a parameter a
callchain_cursor struct pointer, make that be the case for some more
function so that we can start phasing out usage of yet another global
variable.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-djko3097eyg2rn66v2qcqfvn@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

9 files changed, 33 insertions, 22 deletions

diff --git a/tools/perf/builtin-kmem.c b/tools/perf/builtin-kmem.c
index c9cb3be47cff..58adfee230de 100644
--- a/tools/perf/builtin-kmem.c
+++ b/tools/perf/builtin-kmem.c
@@ -375,7 +375,7 @@ static u64 find_callsite(struct perf_evsel *evsel, struct perf_sample *sample)
         }
 
         al.thread = machine__findnew_thread(machine, sample->pid, sample->tid);
-        sample__resolve_callchain(sample, NULL, evsel, &al, 16);
+        sample__resolve_callchain(sample, &callchain_cursor, NULL, evsel, &al, 16);
 
         callchain_cursor_commit(&callchain_cursor);
         while (true) {
diff --git a/tools/perf/util/callchain.c b/tools/perf/util/callchain.c
index 24b4bd0d7754..2b4ceaf058bb 100644
--- a/tools/perf/util/callchain.c
+++ b/tools/perf/util/callchain.c
@@ -788,7 +788,8 @@ int callchain_cursor_append(struct callchain_cursor *cursor,
         return 0;
 }
 
-int sample__resolve_callchain(struct perf_sample *sample, struct symbol **parent,
+int sample__resolve_callchain(struct perf_sample *sample,
+                              struct callchain_cursor *cursor, struct symbol **parent,
                               struct perf_evsel *evsel, struct addr_location *al,
                               int max_stack)
 {
@@ -797,7 +798,7 @@ int sample__resolve_callchain(struct perf_sample *sample, struct symbol **parent
 
         if (symbol_conf.use_callchain || symbol_conf.cumulate_callchain ||
             sort__has_parent) {
-                return thread__resolve_callchain(al->thread, evsel, sample,
+                return thread__resolve_callchain(al->thread, cursor, evsel, sample,
                                                  parent, al, max_stack);
         }
         return 0;
diff --git a/tools/perf/util/callchain.h b/tools/perf/util/callchain.h
index d2a9e694810c..cae5a7b1f5c8 100644
--- a/tools/perf/util/callchain.h
+++ b/tools/perf/util/callchain.h
@@ -212,7 +212,8 @@ struct hist_entry;
 int record_parse_callchain_opt(const struct option *opt, const char *arg, int unset);
 int record_callchain_opt(const struct option *opt, const char *arg, int unset);
 
-int sample__resolve_callchain(struct perf_sample *sample, struct symbol **parent,
+int sample__resolve_callchain(struct perf_sample *sample,
+                              struct callchain_cursor *cursor, struct symbol **parent,
                               struct perf_evsel *evsel, struct addr_location *al,
                               int max_stack);
 int hist_entry__append_callchain(struct hist_entry *he, struct perf_sample *sample);
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 6e86598682be..38f464a4fa04 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -2349,6 +2349,7 @@ int perf_evsel__fprintf_callchain(struct perf_evsel *evsel, struct perf_sample *
                                   FILE *fp)
 {
         int printed = 0;
+        struct callchain_cursor cursor;
         struct callchain_cursor_node *node;
         int print_ip = print_opts & EVSEL__PRINT_IP;
         int print_sym = print_opts & EVSEL__PRINT_SYM;
@@ -2362,14 +2363,14 @@ int perf_evsel__fprintf_callchain(struct perf_evsel *evsel, struct perf_sample *
         if (sample->callchain) {
                 struct addr_location node_al;
 
-                if (thread__resolve_callchain(al->thread, evsel,
+                if (thread__resolve_callchain(al->thread, &cursor, evsel,
                                               sample, NULL, NULL,
                                               stack_depth) != 0) {
                         if (verbose)
                                 error("Failed to resolve callchain. Skipping\n");
                         return printed;
                 }
-                callchain_cursor_commit(&callchain_cursor);
+                callchain_cursor_commit(&cursor);
 
                 if (print_symoffset)
                         node_al = *al;
@@ -2377,7 +2378,7 @@ int perf_evsel__fprintf_callchain(struct perf_evsel *evsel, struct perf_sample *
                 while (stack_depth) {
                         u64 addr = 0;
 
-                        node = callchain_cursor_current(&callchain_cursor);
+                        node = callchain_cursor_current(&cursor);
                         if (!node)
                                 break;
 
@@ -2420,7 +2421,7 @@ int perf_evsel__fprintf_callchain(struct perf_evsel *evsel, struct perf_sample *
 
                         stack_depth--;
 next:
-                        callchain_cursor_advance(&callchain_cursor);
+                        callchain_cursor_advance(&cursor);
                 }
         }
 
diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c
index 3d34c57dfbe2..991a351a8a41 100644
--- a/tools/perf/util/hist.c
+++ b/tools/perf/util/hist.c
@@ -953,7 +953,7 @@ int hist_entry_iter__add(struct hist_entry_iter *iter, struct addr_location *al,
 {
         int err, err2;
 
-        err = sample__resolve_callchain(iter->sample, &iter->parent,
+        err = sample__resolve_callchain(iter->sample, &callchain_cursor, &iter->parent,
                                         iter->evsel, al, max_stack_depth);
         if (err)
                 return err;
diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index 80b9b6a87990..0c4dabc69932 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -1599,6 +1599,7 @@ struct mem_info *sample__resolve_mem(struct perf_sample *sample,
 }
 
 static int add_callchain_ip(struct thread *thread,
+                            struct callchain_cursor *cursor,
                             struct symbol **parent,
                             struct addr_location *root_al,
                             u8 *cpumode,
@@ -1630,7 +1631,7 @@ static int add_callchain_ip(struct thread *thread,
                                  * It seems the callchain is corrupted.
                                  * Discard all.
                                  */
-                                callchain_cursor_reset(&callchain_cursor);
+                                callchain_cursor_reset(cursor);
                                 return 1;
                         }
                         return 0;
@@ -1648,13 +1649,13 @@ static int add_callchain_ip(struct thread *thread,
                         /* Treat this symbol as the root,
                            forgetting its callees. */
                         *root_al = al;
-                        callchain_cursor_reset(&callchain_cursor);
+                        callchain_cursor_reset(cursor);
                 }
         }
 
         if (symbol_conf.hide_unresolved && al.sym == NULL)
                 return 0;
-        return callchain_cursor_append(&callchain_cursor, al.addr, al.map, al.sym);
+        return callchain_cursor_append(cursor, al.addr, al.map, al.sym);
 }
 
 struct branch_info *sample__resolve_bstack(struct perf_sample *sample,
@@ -1724,6 +1725,7 @@ static int remove_loops(struct branch_entry *l, int nr)
  * negative error code on other errors.
  */
 static int resolve_lbr_callchain_sample(struct thread *thread,
+                                        struct callchain_cursor *cursor,
                                         struct perf_sample *sample,
                                         struct symbol **parent,
                                         struct addr_location *root_al,
@@ -1778,7 +1780,7 @@ static int resolve_lbr_callchain_sample(struct thread *thread,
                                         ip = lbr_stack->entries[0].to;
                         }
 
-                        err = add_callchain_ip(thread, parent, root_al, &cpumode, ip);
+                        err = add_callchain_ip(thread, cursor, parent, root_al, &cpumode, ip);
                         if (err)
                                 return (err < 0) ? err : 0;
                 }
@@ -1789,6 +1791,7 @@ static int resolve_lbr_callchain_sample(struct thread *thread,
 }
 
 static int thread__resolve_callchain_sample(struct thread *thread,
+                                            struct callchain_cursor *cursor,
                                             struct perf_evsel *evsel,
                                             struct perf_sample *sample,
                                             struct symbol **parent,
@@ -1803,10 +1806,10 @@ static int thread__resolve_callchain_sample(struct thread *thread,
         int skip_idx = -1;
         int first_call = 0;
 
-        callchain_cursor_reset(&callchain_cursor);
+        callchain_cursor_reset(cursor);
 
         if (has_branch_callstack(evsel)) {
-                err = resolve_lbr_callchain_sample(thread, sample, parent,
+                err = resolve_lbr_callchain_sample(thread, cursor, sample, parent,
                                                    root_al, max_stack);
                 if (err)
                         return (err < 0) ? err : 0;
@@ -1863,10 +1866,10 @@ static int thread__resolve_callchain_sample(struct thread *thread,
                 nr = remove_loops(be, nr);
 
                 for (i = 0; i < nr; i++) {
-                        err = add_callchain_ip(thread, parent, root_al,
+                        err = add_callchain_ip(thread, cursor, parent, root_al,
                                                NULL, be[i].to);
                         if (!err)
-                                err = add_callchain_ip(thread, parent, root_al,
+                                err = add_callchain_ip(thread, cursor, parent, root_al,
                                                        NULL, be[i].from);
                         if (err == -EINVAL)
                                 break;
@@ -1896,7 +1899,7 @@ check_calls:
 #endif
                 ip = chain->ips[j];
 
-                err = add_callchain_ip(thread, parent, root_al, &cpumode, ip);
+                err = add_callchain_ip(thread, cursor, parent, root_al, &cpumode, ip);
 
                 if (err)
                         return (err < 0) ? err : 0;
@@ -1916,13 +1919,14 @@ static int unwind_entry(struct unwind_entry *entry, void *arg)
 }
 
 int thread__resolve_callchain(struct thread *thread,
+                              struct callchain_cursor *cursor,
                               struct perf_evsel *evsel,
                               struct perf_sample *sample,
                               struct symbol **parent,
                               struct addr_location *root_al,
                               int max_stack)
 {
-        int ret = thread__resolve_callchain_sample(thread, evsel,
+        int ret = thread__resolve_callchain_sample(thread, cursor, evsel,
                                                    sample, parent,
                                                    root_al, max_stack);
         if (ret)
@@ -1938,7 +1942,7 @@ int thread__resolve_callchain(struct thread *thread,
             (!sample->user_stack.size))
                 return 0;
 
-        return unwind__get_entries(unwind_entry, &callchain_cursor,
+        return unwind__get_entries(unwind_entry, cursor,
                                    thread, sample, max_stack);
 
 }
diff --git a/tools/perf/util/machine.h b/tools/perf/util/machine.h
index 8499db281158..382873bdc563 100644
--- a/tools/perf/util/machine.h
+++ b/tools/perf/util/machine.h
@@ -141,7 +141,11 @@ struct branch_info *sample__resolve_bstack(struct perf_sample *sample,
                                            struct addr_location *al);
 struct mem_info *sample__resolve_mem(struct perf_sample *sample,
                                      struct addr_location *al);
+
+struct callchain_cursor;
+
 int thread__resolve_callchain(struct thread *thread,
+                              struct callchain_cursor *cursor,
                               struct perf_evsel *evsel,
                               struct perf_sample *sample,
                               struct symbol **parent,
diff --git a/tools/perf/util/scripting-engines/trace-event-perl.c b/tools/perf/util/scripting-engines/trace-event-perl.c
index 35ed00a600fb..ae1cebc307c5 100644
--- a/tools/perf/util/scripting-engines/trace-event-perl.c
+++ b/tools/perf/util/scripting-engines/trace-event-perl.c
@@ -263,7 +263,7 @@ static SV *perl_process_callchain(struct perf_sample *sample,
         if (!symbol_conf.use_callchain || !sample->callchain)
                 goto exit;
 
-        if (thread__resolve_callchain(al->thread, evsel,
+        if (thread__resolve_callchain(al->thread, &callchain_cursor, evsel,
                                       sample, NULL, NULL,
                                       PERF_MAX_STACK_DEPTH) != 0) {
                 pr_err("Failed to resolve callchain. Skipping\n");
diff --git a/tools/perf/util/scripting-engines/trace-event-python.c b/tools/perf/util/scripting-engines/trace-event-python.c
index fbd05242b4e5..525eb49e7ba6 100644
--- a/tools/perf/util/scripting-engines/trace-event-python.c
+++ b/tools/perf/util/scripting-engines/trace-event-python.c
@@ -323,7 +323,7 @@ static PyObject *python_process_callchain(struct perf_sample *sample,
         if (!symbol_conf.use_callchain || !sample->callchain)
                 goto exit;
 
-        if (thread__resolve_callchain(al->thread, evsel,
+        if (thread__resolve_callchain(al->thread, &callchain_cursor, evsel,
                                       sample, NULL, NULL,
                                       scripting_max_stack) != 0) {
                 pr_err("Failed to resolve callchain. Skipping\n");