Re: [PATCH v2] perf report: Make --branch-history work without callgraphs(-g) option in perf record

From: Jin, Yao
Date: Sun Jul 23 2017 - 23:50:17 EST


Hi Arnaldo,

Is this patch OK for merging? It's more than 2 months no more comments.

Thanks
Jin Yao


On 5/8/2017 6:43 PM, Jin Yao wrote:
perf record -b -g <command>
perf report --branch-history

This merges the LBRs with the callgraphs.

However it would be nice if it also works without callgraphs (-g)
set in perf record, so that only the LBRs are displayed.
But currently perf report errors in this case. For example,

perf record -b <command>
perf report --branch-history

Error:
Selected -g or --branch-history but no callchain data. Did
you call 'perf record' without -g?

This patch displays the LBRs only even if callgraphs(-g) is not
enabled in perf record.

Change log:
----------
v2: According to Milian Wolff's comment, change the obsolete error
message. Now the error message is:

ââError:ââââââââââââââââââââââââââââââââââââââ
âSelected -g or --branch-history. â
âBut no callchain or branch data. â
âDid you call 'perf record' without -g or -b?â
â â
â â
âPress any key... â
ââââââââââââââââââââââââââââââââââââââââââââââ

When passing the last parameter to hists__fprintf,
changes "|" to "||".

hsts__fprintf(hists, !quiet, 0, 0, rep->min_percent, stdout,
symbol_conf.use_callchain ||
symbol_conf.show_branchflag_count);

Signed-off-by: Jin Yao <yao.jin@xxxxxxxxxxxxxxx>
---
tools/perf/builtin-report.c | 12 +++++++-----
tools/perf/util/callchain.c | 7 ++++---
tools/perf/util/hist.c | 2 ++
tools/perf/util/machine.c | 13 ++++++++++++-
4 files changed, 25 insertions(+), 9 deletions(-)

diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index 22478ff..4ceb2d2 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -259,10 +259,11 @@ static int report__setup_sample_type(struct report *rep)
"'perf record' without -g?\n");
return -EINVAL;
}
- if (symbol_conf.use_callchain) {
- ui__error("Selected -g or --branch-history but no "
- "callchain data. Did\n"
- "you call 'perf record' without -g?\n");
+ if (symbol_conf.use_callchain &&
+ !symbol_conf.show_branchflag_count) {
+ ui__error("Selected -g or --branch-history.\n"
+ "But no callchain or branch data.\n"
+ "Did you call 'perf record' without -g or -b?\n");
return -1;
}
} else if (!callchain_param.enabled &&
@@ -397,7 +398,8 @@ static int perf_evlist__tty_browse_hists(struct perf_evlist *evlist,
hists__fprintf_nr_sample_events(hists, rep, evname, stdout);
hists__fprintf(hists, !quiet, 0, 0, rep->min_percent, stdout,
- symbol_conf.use_callchain);
+ symbol_conf.use_callchain ||
+ symbol_conf.show_branchflag_count);
fprintf(stdout, "\n\n");
}
diff --git a/tools/perf/util/callchain.c b/tools/perf/util/callchain.c
index 81fc29a..08d3abf 100644
--- a/tools/perf/util/callchain.c
+++ b/tools/perf/util/callchain.c
@@ -993,11 +993,11 @@ int sample__resolve_callchain(struct perf_sample *sample,
struct perf_evsel *evsel, struct addr_location *al,
int max_stack)
{
- if (sample->callchain == NULL)
+ if (sample->callchain == NULL && !symbol_conf.show_branchflag_count)
return 0;
if (symbol_conf.use_callchain || symbol_conf.cumulate_callchain ||
- perf_hpp_list.parent) {
+ perf_hpp_list.parent || symbol_conf.show_branchflag_count) {
return thread__resolve_callchain(al->thread, cursor, evsel, sample,
parent, al, max_stack);
}
@@ -1006,7 +1006,8 @@ int sample__resolve_callchain(struct perf_sample *sample,
int hist_entry__append_callchain(struct hist_entry *he, struct perf_sample *sample)
{
- if (!symbol_conf.use_callchain || sample->callchain == NULL)
+ if ((!symbol_conf.use_callchain || sample->callchain == NULL) &&
+ !symbol_conf.show_branchflag_count)
return 0;
return callchain_append(he->callchain, &callchain_cursor, sample->period);
}
diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c
index cf0186a..8b045a5 100644
--- a/tools/perf/util/hist.c
+++ b/tools/perf/util/hist.c
@@ -1762,6 +1762,8 @@ void perf_evsel__output_resort(struct perf_evsel *evsel, struct ui_progress *pro
else
use_callchain = symbol_conf.use_callchain;
+ use_callchain |= symbol_conf.show_branchflag_count;
+
output_resort(evsel__hists(evsel), prog, use_callchain, NULL);
}
diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index d97e014..7b47080 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -1901,13 +1901,16 @@ static int thread__resolve_callchain_sample(struct thread *thread,
{
struct branch_stack *branch = sample->branch_stack;
struct ip_callchain *chain = sample->callchain;
- int chain_nr = chain->nr;
+ int chain_nr = 0;
u8 cpumode = PERF_RECORD_MISC_USER;
int i, j, err, nr_entries;
int skip_idx = -1;
int first_call = 0;
int nr_loop_iter;
+ if (chain)
+ chain_nr = chain->nr;
+
if (perf_evsel__has_branch_callstack(evsel)) {
err = resolve_lbr_callchain_sample(thread, cursor, sample, parent,
root_al, max_stack);
@@ -1945,6 +1948,10 @@ static int thread__resolve_callchain_sample(struct thread *thread,
for (i = 0; i < nr; i++) {
if (callchain_param.order == ORDER_CALLEE) {
be[i] = branch->entries[i];
+
+ if (chain == NULL)
+ continue;
+
/*
* Check for overlap into the callchain.
* The return address is one off compared to
@@ -1998,6 +2005,10 @@ static int thread__resolve_callchain_sample(struct thread *thread,
if (err)
return err;
}
+
+ if (chain_nr == 0)
+ return 0;
+
chain_nr -= nr;
}