[PATCH V4 08/17] perf machine: Factor out lbr_callchain_add_lbr_ip()

From: kan . liang
Date: Thu Mar 19 2020 - 16:29:31 EST


From: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>

Both caller and callee needs to add ip from LBR to callchain.
Factor out lbr_callchain_add_lbr_ip() to improve code readability.

Reviewed-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Signed-off-by: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
---
tools/perf/util/machine.c | 143 +++++++++++++++++++-------------------
1 file changed, 73 insertions(+), 70 deletions(-)

diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index ef26f28eacea..f1661dd3ca69 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -2193,6 +2193,74 @@ static int lbr_callchain_add_kernel_ip(struct thread *thread,
return 0;
}

+static int lbr_callchain_add_lbr_ip(struct thread *thread,
+ struct callchain_cursor *cursor,
+ struct perf_sample *sample,
+ struct symbol **parent,
+ struct addr_location *root_al,
+ u64 *branch_from,
+ bool callee)
+{
+ struct branch_stack *lbr_stack = sample->branch_stack;
+ struct branch_entry *entries = perf_sample__branch_entries(sample);
+ u8 cpumode = PERF_RECORD_MISC_USER;
+ int lbr_nr = lbr_stack->nr;
+ struct branch_flags *flags;
+ int err, i;
+ u64 ip;
+
+ if (callee) {
+ /* Add LBR ip from first entries.to */
+ ip = entries[0].to;
+ flags = &entries[0].flags;
+ *branch_from = entries[0].from;
+ err = add_callchain_ip(thread, cursor, parent,
+ root_al, &cpumode, ip,
+ true, flags, NULL,
+ *branch_from);
+ if (err)
+ return err;
+
+ /* Add LBR ip from entries.from one by one. */
+ for (i = 0; i < lbr_nr; i++) {
+ ip = entries[i].from;
+ flags = &entries[i].flags;
+ err = add_callchain_ip(thread, cursor, parent,
+ root_al, &cpumode, ip,
+ true, flags, NULL,
+ *branch_from);
+ if (err)
+ return err;
+ }
+ return 0;
+ }
+
+ /* Add LBR ip from entries.from one by one. */
+ for (i = lbr_nr - 1; i >= 0; i--) {
+ ip = entries[i].from;
+ flags = &entries[i].flags;
+ err = add_callchain_ip(thread, cursor, parent,
+ root_al, &cpumode, ip,
+ true, flags, NULL,
+ *branch_from);
+ if (err)
+ return err;
+ }
+
+ /* Add LBR ip from first entries.to */
+ ip = entries[0].to;
+ flags = &entries[0].flags;
+ *branch_from = entries[0].from;
+ err = add_callchain_ip(thread, cursor, parent,
+ root_al, &cpumode, ip,
+ true, flags, NULL,
+ *branch_from);
+ if (err)
+ return err;
+
+ return 0;
+}
+
/*
* Recolve LBR callstack chain sample
* Return:
@@ -2209,14 +2277,7 @@ static int resolve_lbr_callchain_sample(struct thread *thread,
{
struct ip_callchain *chain = sample->callchain;
int chain_nr = min(max_stack, (int)chain->nr), i;
- u8 cpumode = PERF_RECORD_MISC_USER;
- u64 ip, branch_from = 0;
- struct branch_stack *lbr_stack;
- struct branch_entry *entries;
- int lbr_nr, j, k;
- bool branch;
- struct branch_flags *flags;
- int mix_chain_nr;
+ u64 branch_from = 0;
int err;

for (i = 0; i < chain_nr; i++) {
@@ -2228,21 +2289,6 @@ static int resolve_lbr_callchain_sample(struct thread *thread,
if (i == chain_nr)
return 0;

- lbr_stack = sample->branch_stack;
- entries = perf_sample__branch_entries(sample);
- lbr_nr = lbr_stack->nr;
- /*
- * LBR callstack can only get user call chain.
- * The mix_chain_nr is kernel call chain
- * number plus LBR user call chain number.
- * i is kernel call chain number,
- * 1 is PERF_CONTEXT_USER,
- * lbr_nr + 1 is the user call chain number.
- * For details, please refer to the comments
- * in callchain__printf
- */
- mix_chain_nr = i + 1 + lbr_nr + 1;
-
if (callchain_param.order == ORDER_CALLEE) {
/* Add kernel ip */
err = lbr_callchain_add_kernel_ip(thread, cursor, sample,
@@ -2251,57 +2297,14 @@ static int resolve_lbr_callchain_sample(struct thread *thread,
if (err)
goto error;

- /* Add LBR ip from first entries.to */
- ip = entries[0].to;
- branch = true;
- flags = &entries[0].flags;
- branch_from = entries[0].from;
- err = add_callchain_ip(thread, cursor, parent,
- root_al, &cpumode, ip,
- branch, flags, NULL,
- branch_from);
+ err = lbr_callchain_add_lbr_ip(thread, cursor, sample, parent,
+ root_al, &branch_from, true);
if (err)
goto error;

- /* Add LBR ip from entries.from one by one. */
- for (j = i + 2; j < mix_chain_nr; j++) {
- k = j - i - 2;
- ip = entries[k].from;
- branch = true;
- flags = &entries[k].flags;
-
- err = add_callchain_ip(thread, cursor, parent,
- root_al, &cpumode, ip,
- branch, flags, NULL,
- branch_from);
- if (err)
- goto error;
- }
} else {
- /* Add LBR ip from entries.from one by one. */
- for (j = 0; j < lbr_nr; j++) {
- k = lbr_nr - j - 1;
- ip = entries[k].from;
- branch = true;
- flags = &entries[k].flags;
-
- err = add_callchain_ip(thread, cursor, parent,
- root_al, &cpumode, ip,
- branch, flags, NULL,
- branch_from);
- if (err)
- goto error;
- }
-
- /* Add LBR ip from first entries.to */
- ip = entries[0].to;
- branch = true;
- flags = &entries[0].flags;
- branch_from = entries[0].from;
- err = add_callchain_ip(thread, cursor, parent,
- root_al, &cpumode, ip,
- branch, flags, NULL,
- branch_from);
+ err = lbr_callchain_add_lbr_ip(thread, cursor, sample, parent,
+ root_al, &branch_from, false);
if (err)
goto error;

--
2.17.1