[PATCH 02/15] perf callchain: Start moving away from global per thread cursors

From: Arnaldo Carvalho de Melo
Date: Fri Apr 15 2016 - 17:54:08 EST


From: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>

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@xxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Wang Nan <wangnan0@xxxxxxxxxx>
Link: http://lkml.kernel.org/n/tip-djko3097eyg2rn66v2qcqfvn@xxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/builtin-kmem.c | 2 +-
tools/perf/util/callchain.c | 5 +++--
tools/perf/util/callchain.h | 3 ++-
tools/perf/util/evsel.c | 9 ++++----
tools/perf/util/hist.c | 2 +-
tools/perf/util/machine.c | 26 +++++++++++++---------
tools/perf/util/machine.h | 4 ++++
.../perf/util/scripting-engines/trace-event-perl.c | 2 +-
.../util/scripting-engines/trace-event-python.c | 2 +-
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");
--
2.5.5