From: Leo Yan <leo.yan@arm.com>
To: Arnaldo Carvalho de Melo <acme@kernel.org>,
John Garry <john.g.garry@oracle.com>,
Will Deacon <will@kernel.org>,
James Clark <james.clark@linaro.org>,
Mike Leach <mike.leach@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Namhyung Kim <namhyung@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Jiri Olsa <jolsa@kernel.org>, Ian Rogers <irogers@google.com>,
Adrian Hunter <adrian.hunter@intel.com>,
Al Grant <al.grant@arm.com>,
Paschalis Mpeis <paschalis.mpeis@arm.com>,
Amir Ayupov <aaupov@fb.com>
Cc: linux-arm-kernel@lists.infradead.org, coresight@lists.linaro.org,
linux-perf-users@vger.kernel.org, Leo Yan <leo.yan@arm.com>,
Leo Yan <leo.yan@linux.dev>
Subject: [PATCH v11 7/9] perf cs-etm: Support call indentation
Date: Thu, 02 Jul 2026 20:51:42 +0100 [thread overview]
Message-ID: <20260702-b4-arm_cs_callchain_support_v1-v11-7-846abbf600d7@arm.com> (raw)
In-Reply-To: <20260702-b4-arm_cs_callchain_support_v1-v11-0-846abbf600d7@arm.com>
From: Leo Yan <leo.yan@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@linaro.org>
Reviewed-by: James Clark <james.clark@linaro.org>
Signed-off-by: Leo Yan <leo.yan@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 996317687ce7b241afed83444b554155edb09564..f76648fa67681c464faf5e9cf4e019653bce5b4c 100644
--- a/tools/perf/util/cs-etm.c
+++ b/tools/perf/util/cs-etm.c
@@ -67,6 +67,8 @@ 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;
@@ -656,7 +658,7 @@ 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 *
@@ -1572,7 +1574,7 @@ 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);
@@ -1581,7 +1583,8 @@ 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,
@@ -1991,7 +1994,7 @@ 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;
@@ -2054,7 +2057,7 @@ 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;
switch (pid_fmt) {
@@ -3556,6 +3559,7 @@ 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)
@@ -3617,6 +3621,12 @@ 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
next prev parent reply other threads:[~2026-07-02 19:52 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-02 19:51 [PATCH v11 0/9] perf cs-etm: Support thread stack and callchain Leo Yan
2026-07-02 19:51 ` [PATCH v11 1/9] perf cs-etm: Fix thread leaks on trace queue init failure Leo Yan
2026-07-02 19:51 ` [PATCH v11 2/9] perf cs-etm: Filter synthesized branch samples Leo Yan
2026-07-02 19:51 ` [PATCH v11 3/9] perf cs-etm: Decode ETE exception packets Leo Yan
2026-07-02 19:51 ` [PATCH v11 4/9] perf cs-etm: Refactor instruction size handling Leo Yan
2026-07-02 19:51 ` [PATCH v11 5/9] perf cs-etm: Use thread-stack for last branch entries Leo Yan
2026-07-02 19:51 ` [PATCH v11 6/9] perf cs-etm: Flush thread stacks after decoder reset Leo Yan
2026-07-02 19:51 ` Leo Yan [this message]
2026-07-02 19:51 ` [PATCH v11 8/9] perf cs-etm: Synthesize callchains for instruction samples Leo Yan
2026-07-02 19:51 ` [PATCH v11 9/9] perf test: Add Arm CoreSight callchain test Leo Yan
2026-07-04 16:11 ` [PATCH v11 0/9] perf cs-etm: Support thread stack and callchain Namhyung Kim
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