[PATCH v8 6/8] perf cs-etm: Support call indentation
Leo Yan
leo.yan at arm.com
Thu Jun 11 07:50:52 PDT 2026
From: Leo Yan <leo.yan at linaro.org>
The perf script callindent is derived from call stack in thread context,
CS ETM ignores the requirement for callindent without pushing and poping
call stack.
Enable thread-stack when either itrace thread-stack support or last branch
entries are requested, allocate the branch stack storage accordingly, and
feed taken branches to thread_stack__event() whenever thread-stack state
is needed.
When callindent is requested, pass callstack=true to thread_stack__event()
so the common thread-stack code maintains call depth for branch samples.
Before:
perf script -F +callindent
callchain_test 6543 [002] 1 branches: main ffff93252258 __libc_start_call_main+0x78 (/usr/lib/aarch64-linux-gnu/libc.so.6)
callchain_test 6543 [002] 1 branches: foo aaaad6b607c4 main+0x8 (/home/kernel/leoy/test_cs_callchain/callchain_test)
callchain_test 6543 [002] 1 branches: print aaaad6b607ac foo+0x8 (/home/kernel/leoy/test_cs_callchain/callchain_test)
callchain_test 6543 [002] 1 branches: do_svc aaaad6b60794 print+0x8 (/home/kernel/leoy/test_cs_callchain/callchain_test)
callchain_test 6543 [002] 1 branches: vectors aaaad6b60780 do_svc+0x18 (/home/kernel/leoy/test_cs_callchain/callchain_test)
callchain_test 6543 [002] 1 branches: el0t_64_sync_handler ffff80008001159c el0t_64_sync+0x194 ([kernel.kallsyms])
callchain_test 6543 [002] 1 branches: el0_svc ffff800081829194 el0t_64_sync_handler+0x9c ([kernel.kallsyms])
callchain_test 6543 [002] 1 branches: lockdep_hardirqs_off ffff800081828794 el0_svc+0x24 ([kernel.kallsyms])
callchain_test 6543 [002] 1 branches: __this_cpu_preempt_check ffff80008182b348 lockdep_hardirqs_off+0xf0 ([kernel.kallsyms])
After:
callchain_test 6543 [002] 1 branches: main ffff93252258 __libc_start_call_main+0x78 (/usr/lib/aarch64-linux-gnu/libc.so.6)
callchain_test 6543 [002] 1 branches: foo aaaad6b607c4 main+0x8 (/home/kernel/leoy/test_cs_callchain/callchain_test)
callchain_test 6543 [002] 1 branches: print aaaad6b607ac foo+0x8 (/home/kernel/leoy/test_cs_callchain/callchain_test)
callchain_test 6543 [002] 1 branches: do_svc aaaad6b60794 print+0x8 (/home/kernel/leoy/test_cs_callchain/callchain_test)
callchain_test 6543 [002] 1 branches: vectors aaaad6b60780 do_svc+0x18 (/home/kernel/leoy/test_cs_callchain/callchain_test)
callchain_test 6543 [002] 1 branches: el0t_64_sync_handler ffff80008001159c el0t_64_sync+0x194 ([kernel.kallsyms])
callchain_test 6543 [002] 1 branches: el0_svc ffff800081829194 el0t_64_sync_handler+0x9c ([kernel.kallsyms])
callchain_test 6543 [002] 1 branches: lockdep_hardirqs_off ffff800081828794 el0_svc+0x24 ([kernel.kallsyms])
callchain_test 6543 [002] 1 branches: __this_cpu_preempt_check ffff80008182b348 lockdep_hardirqs_off+0xf0 ([kernel.kallsyms])
Signed-off-by: Leo Yan <leo.yan at linaro.org>
Reviewed-by: James Clark <james.clark at linaro.org>
Signed-off-by: Leo Yan <leo.yan at arm.com>
---
tools/perf/util/cs-etm.c | 20 +++++++++++++++-----
1 file changed, 15 insertions(+), 5 deletions(-)
diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c
index 7069b4990e6107fdece3cc5451142714f1d627ef..830618763d8b1bdcc015c492d7b2354d862566ca 100644
--- a/tools/perf/util/cs-etm.c
+++ b/tools/perf/util/cs-etm.c
@@ -66,6 +66,8 @@ struct cs_etm_auxtrace {
bool snapshot_mode;
bool data_queued;
bool has_virtual_ts; /* Virtual/Kernel timestamps in the trace. */
+ bool use_thread_stack;
+ bool use_callchain;
int num_cpu;
u64 latest_kernel_timestamp;
@@ -635,7 +637,7 @@ static int cs_etm__init_traceid_queue(struct cs_etm_queue *etmq,
if (!tidq->prev_packet)
goto out_free;
- if (etm->synth_opts.last_branch) {
+ if (etm->use_thread_stack) {
size_t sz = sizeof(struct branch_stack);
sz += etm->synth_opts.last_branch_sz *
@@ -1545,7 +1547,7 @@ static void cs_etm__add_stack_event(struct cs_etm_queue *etmq,
if (!cs_etm__packet_has_taken_branch(tidq->prev_packet))
return;
- if (etmq->etm->synth_opts.last_branch) {
+ if (etmq->etm->use_thread_stack) {
from = cs_etm__last_executed_instr(tidq->prev_packet);
to = cs_etm__first_executed_instr(tidq->packet);
@@ -1554,7 +1556,8 @@ static void cs_etm__add_stack_event(struct cs_etm_queue *etmq,
/* Enable callchain so thread stack entry can be allocated */
thread_stack__event(tidq->frontend_thread, tidq->prev_packet->cpu,
tidq->prev_packet->flags, from, to, size,
- etmq->buffer->buffer_nr + 1, false,
+ etmq->buffer->buffer_nr + 1,
+ etmq->etm->use_callchain,
tidq->br_stack_sz, 0);
} else {
thread_stack__set_trace_nr(tidq->frontend_thread,
@@ -1955,7 +1958,7 @@ static int cs_etm__flush(struct cs_etm_queue *etmq,
cs_etm__packet_swap(etm, tidq);
/* Reset last branches after flush the trace */
- if (etm->synth_opts.last_branch)
+ if (etm->use_thread_stack)
thread_stack__flush(tidq->frontend_thread);
return err;
@@ -2018,7 +2021,7 @@ static void cs_etm__flush_all_stack(struct cs_etm_queue *etmq)
{
enum cs_etm_pid_fmt pid_fmt = cs_etm__get_pid_fmt(etmq);
- if (!etmq->etm->synth_opts.last_branch)
+ if (!etmq->etm->use_thread_stack)
return;
cs_etm__flush_machine_stack(etmq, HOST_KERNEL_ID);
@@ -3491,6 +3494,7 @@ int cs_etm__process_auxtrace_info_full(union perf_event *event,
itrace_synth_opts__set_default(&etm->synth_opts,
session->itrace_synth_opts->default_no_sample);
etm->synth_opts.callchain = false;
+ etm->synth_opts.thread_stack = session->itrace_synth_opts->thread_stack;
}
if (etm->synth_opts.calls)
@@ -3552,6 +3556,12 @@ int cs_etm__process_auxtrace_info_full(union perf_event *event,
etm->tc.cap_user_time_zero = tc->cap_user_time_zero;
etm->tc.cap_user_time_short = tc->cap_user_time_short;
}
+
+ etm->use_thread_stack = etm->synth_opts.thread_stack ||
+ etm->synth_opts.last_branch;
+
+ etm->use_callchain = etm->synth_opts.thread_stack;
+
err = cs_etm__synth_events(etm, session);
if (err)
goto err_free_queues;
--
2.34.1
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