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Date: Tue, 19 Apr 2016 01:56:00 -0700
From: Chris Phlipot <cphlipot0@...il.com>
To: acme@...nel.org, adrian.hunter@...el.com, mingo@...hat.com,
peterz@...radead.org
Cc: linux-kernel@...r.kernel.org, Chris Phlipot <cphlipot0@...il.com>
Subject: [PATCH 1/5] perf tools: fix incorrect ordering of callchain entries
The existing implentation implementation of thread__resolve_callchain,
under certain circumstanes, can assemble callchain entries in the
incorrect order.
A the callchain entries are resolved incorrectly for a sample when all
of the following conditions are met:
1. callchain_param.order is set to ORDER_CALLER
2. thread__resolve_callchain_sample is able to resolve callchain entries
for the sample.
3. unwind__get_entries is also able to resolve callchain entries for the
sample.
The fix is accomplished by reversing the order in which
thread__resolve_callchain_sample and unwind__get_entries are called
when callchain_param.order is set to ORDER_CALLER.
Unwind specific code from thread__resolve_callchain is also moved into a
new static function to improve readability of the fix.
Signed-off-by: Chris Phlipot <cphlipot0@...il.com>
---
tools/perf/util/machine.c | 57 ++++++++++++++++++++++++++++++++++-------------
1 file changed, 41 insertions(+), 16 deletions(-)
diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index 0c4dabc..dd086c8 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -1806,8 +1806,6 @@ static int thread__resolve_callchain_sample(struct thread *thread,
int skip_idx = -1;
int first_call = 0;
- callchain_cursor_reset(cursor);
-
if (has_branch_callstack(evsel)) {
err = resolve_lbr_callchain_sample(thread, cursor, sample, parent,
root_al, max_stack);
@@ -1918,20 +1916,12 @@ static int unwind_entry(struct unwind_entry *entry, void *arg)
entry->map, entry->sym);
}
-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, cursor, evsel,
- sample, parent,
- root_al, max_stack);
- if (ret)
- return ret;
-
+static int thread__resolve_callchain_unwind(struct thread *thread,
+ struct callchain_cursor *cursor,
+ struct perf_evsel *evsel,
+ struct perf_sample *sample,
+ int max_stack)
+{
/* Can we do dwarf post unwind? */
if (!((evsel->attr.sample_type & PERF_SAMPLE_REGS_USER) &&
(evsel->attr.sample_type & PERF_SAMPLE_STACK_USER)))
@@ -1944,7 +1934,42 @@ int thread__resolve_callchain(struct thread *thread,
return unwind__get_entries(unwind_entry, cursor,
thread, sample, max_stack);
+}
+
+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 = 0;
+ callchain_cursor_reset(&callchain_cursor);
+
+ if (callchain_param.order == ORDER_CALLEE) {
+ ret = thread__resolve_callchain_sample(thread, cursor,
+ evsel, sample,
+ parent, root_al,
+ max_stack);
+ if (ret)
+ return ret;
+ ret = thread__resolve_callchain_unwind(thread, cursor,
+ evsel, sample,
+ max_stack);
+ } else {
+ ret = thread__resolve_callchain_unwind(thread, cursor,
+ evsel, sample,
+ max_stack);
+ if (ret)
+ return ret;
+ ret = thread__resolve_callchain_sample(thread, cursor,
+ evsel, sample,
+ parent, root_al,
+ max_stack);
+ }
+ return ret;
}
int machine__for_each_thread(struct machine *machine,
--
2.7.4
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