From: Steven Rostedt <rostedt@kernel.org>
To: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org,
bpf@vger.kernel.org, x86@kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Josh Poimboeuf <jpoimboe@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@kernel.org>, Jiri Olsa <jolsa@kernel.org>,
Arnaldo Carvalho de Melo <acme@kernel.org>,
Namhyung Kim <namhyung@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Andrii Nakryiko <andrii@kernel.org>,
Indu Bhagat <indu.bhagat@oracle.com>,
"Jose E. Marchesi" <jemarch@gnu.org>,
Beau Belgrave <beaub@linux.microsoft.com>,
Jens Remus <jremus@linux.ibm.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Andrew Morton <akpm@linux-foundation.org>,
Jens Axboe <axboe@kernel.dk>, Florian Weimer <fweimer@redhat.com>,
Sam James <sam@gentoo.org>
Subject: [PATCH v14 08/11] perf tools: Minimal CALLCHAIN_DEFERRED support
Date: Fri, 18 Jul 2025 12:41:27 -0400 [thread overview]
Message-ID: <20250718164324.423885737@kernel.org> (raw)
In-Reply-To: 20250718164119.089692174@kernel.org
From: Namhyung Kim <namhyung@kernel.org>
Add a new event type for deferred callchains and a new callback for the
struct perf_tool. For now it doesn't actually handle the deferred
callchains but it just marks the sample if it has the PERF_CONTEXT_
USER_DEFFERED in the callchain array.
At least, perf report can dump the raw data with this change. Actually
this requires the next commit to enable attr.defer_callchain, but if you
already have a data file, it'll show the following result.
$ perf report -D
...
0x5fe0@perf.data [0x40]: event: 22
.
. ... raw event: size 64 bytes
. 0000: 16 00 00 00 02 00 40 00 02 00 00 00 00 00 00 00 ......@.........
. 0010: 00 fe ff ff ff ff ff ff 4b d3 3f 25 45 7f 00 00 ........K.?%E...
. 0020: 21 03 00 00 21 03 00 00 43 02 12 ab 05 00 00 00 !...!...C.......
. 0030: 00 00 00 00 00 00 00 00 09 00 00 00 00 00 00 00 ................
0 24344920643 0x5fe0 [0x40]: PERF_RECORD_CALLCHAIN_DEFERRED(IP, 0x2): 801/801: 0 [300000001]
... FP chain: nr:2
..... 0: fffffffffffffe00
..... 1: 00007f45253fd34b
: unhandled!
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
Changes since v13: https://lore.kernel.org/20250708020051.268700027@kernel.org
- Added back the cookie in the deferred event
- Display the cookie in the -D output
tools/lib/perf/include/perf/event.h | 8 ++++++++
tools/perf/util/event.c | 1 +
tools/perf/util/evsel.c | 15 +++++++++++++++
tools/perf/util/machine.c | 1 +
tools/perf/util/perf_event_attr_fprintf.c | 1 +
tools/perf/util/sample.h | 3 ++-
tools/perf/util/session.c | 18 ++++++++++++++++++
tools/perf/util/tool.c | 1 +
tools/perf/util/tool.h | 3 ++-
9 files changed, 49 insertions(+), 2 deletions(-)
diff --git a/tools/lib/perf/include/perf/event.h b/tools/lib/perf/include/perf/event.h
index 09b7c643ddac..5801b0124067 100644
--- a/tools/lib/perf/include/perf/event.h
+++ b/tools/lib/perf/include/perf/event.h
@@ -151,6 +151,13 @@ struct perf_record_switch {
__u32 next_prev_tid;
};
+struct perf_record_callchain_deferred {
+ struct perf_event_header header;
+ __u64 cookie;
+ __u64 nr;
+ __u64 ips[];
+};
+
struct perf_record_header_attr {
struct perf_event_header header;
struct perf_event_attr attr;
@@ -505,6 +512,7 @@ union perf_event {
struct perf_record_read read;
struct perf_record_throttle throttle;
struct perf_record_sample sample;
+ struct perf_record_callchain_deferred callchain_deferred;
struct perf_record_bpf_event bpf;
struct perf_record_ksymbol ksymbol;
struct perf_record_text_poke_event text_poke;
diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
index 7544a3104e21..720682fea9be 100644
--- a/tools/perf/util/event.c
+++ b/tools/perf/util/event.c
@@ -58,6 +58,7 @@ static const char *perf_event__names[] = {
[PERF_RECORD_CGROUP] = "CGROUP",
[PERF_RECORD_TEXT_POKE] = "TEXT_POKE",
[PERF_RECORD_AUX_OUTPUT_HW_ID] = "AUX_OUTPUT_HW_ID",
+ [PERF_RECORD_CALLCHAIN_DEFERRED] = "CALLCHAIN_DEFERRED",
[PERF_RECORD_HEADER_ATTR] = "ATTR",
[PERF_RECORD_HEADER_EVENT_TYPE] = "EVENT_TYPE",
[PERF_RECORD_HEADER_TRACING_DATA] = "TRACING_DATA",
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index d55482f094bf..6176c31b57ea 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -2978,6 +2978,18 @@ int evsel__parse_sample(struct evsel *evsel, union perf_event *event,
data->data_src = PERF_MEM_DATA_SRC_NONE;
data->vcpu = -1;
+ if (event->header.type == PERF_RECORD_CALLCHAIN_DEFERRED) {
+ const u64 max_callchain_nr = UINT64_MAX / sizeof(u64);
+
+ data->callchain = (struct ip_callchain *)&event->callchain_deferred.nr;
+ if (data->callchain->nr > max_callchain_nr)
+ return -EFAULT;
+
+ if (evsel->core.attr.sample_id_all)
+ perf_evsel__parse_id_sample(evsel, event, data);
+ return 0;
+ }
+
if (event->header.type != PERF_RECORD_SAMPLE) {
if (!evsel->core.attr.sample_id_all)
return 0;
@@ -3108,6 +3120,9 @@ int evsel__parse_sample(struct evsel *evsel, union perf_event *event,
if (data->callchain->nr > max_callchain_nr)
return -EFAULT;
sz = data->callchain->nr * sizeof(u64);
+ if (evsel->core.attr.defer_callchain && data->callchain->nr >= 1 &&
+ data->callchain->ips[data->callchain->nr - 1] == PERF_CONTEXT_USER_DEFERRED)
+ data->deferred_callchain = true;
OVERFLOW_CHECK(array, sz, max_size);
array = (void *)array + sz;
}
diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index 7ec12c207970..de6100366eee 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -2124,6 +2124,7 @@ static int add_callchain_ip(struct thread *thread,
*cpumode = PERF_RECORD_MISC_KERNEL;
break;
case PERF_CONTEXT_USER:
+ case PERF_CONTEXT_USER_DEFERRED:
*cpumode = PERF_RECORD_MISC_USER;
break;
default:
diff --git a/tools/perf/util/perf_event_attr_fprintf.c b/tools/perf/util/perf_event_attr_fprintf.c
index 66b666d9ce64..abfd9b9a718c 100644
--- a/tools/perf/util/perf_event_attr_fprintf.c
+++ b/tools/perf/util/perf_event_attr_fprintf.c
@@ -343,6 +343,7 @@ int perf_event_attr__fprintf(FILE *fp, struct perf_event_attr *attr,
PRINT_ATTRf(inherit_thread, p_unsigned);
PRINT_ATTRf(remove_on_exec, p_unsigned);
PRINT_ATTRf(sigtrap, p_unsigned);
+ PRINT_ATTRf(defer_callchain, p_unsigned);
PRINT_ATTRn("{ wakeup_events, wakeup_watermark }", wakeup_events, p_unsigned, false);
PRINT_ATTRf(bp_type, p_unsigned);
diff --git a/tools/perf/util/sample.h b/tools/perf/util/sample.h
index 0e96240052e9..9d6e2f14551c 100644
--- a/tools/perf/util/sample.h
+++ b/tools/perf/util/sample.h
@@ -108,7 +108,8 @@ struct perf_sample {
u16 p_stage_cyc;
u16 retire_lat;
};
- bool no_hw_idx; /* No hw_idx collected in branch_stack */
+ bool no_hw_idx; /* No hw_idx collected in branch_stack */
+ bool deferred_callchain; /* Has deferred user callchains */
char insn[MAX_INSN];
void *raw_data;
struct ip_callchain *callchain;
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index a320672c264e..32154d230f6c 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -715,6 +715,7 @@ static perf_event__swap_op perf_event__swap_ops[] = {
[PERF_RECORD_CGROUP] = perf_event__cgroup_swap,
[PERF_RECORD_TEXT_POKE] = perf_event__text_poke_swap,
[PERF_RECORD_AUX_OUTPUT_HW_ID] = perf_event__all64_swap,
+ [PERF_RECORD_CALLCHAIN_DEFERRED] = perf_event__all64_swap,
[PERF_RECORD_HEADER_ATTR] = perf_event__hdr_attr_swap,
[PERF_RECORD_HEADER_EVENT_TYPE] = perf_event__event_type_swap,
[PERF_RECORD_HEADER_TRACING_DATA] = perf_event__tracing_data_swap,
@@ -1118,6 +1119,20 @@ static void dump_sample(struct evsel *evsel, union perf_event *event,
sample_read__printf(sample, evsel->core.attr.read_format);
}
+static void dump_deferred_callchain(struct evsel *evsel, union perf_event *event,
+ struct perf_sample *sample)
+{
+ if (!dump_trace)
+ return;
+
+ printf("(IP, 0x%x): %d/%d: %#" PRIx64 " [%llx]\n",
+ event->header.misc, sample->pid, sample->tid, sample->ip,
+ event->callchain_deferred.cookie);
+
+ if (evsel__has_callchain(evsel))
+ callchain__printf(evsel, sample);
+}
+
static void dump_read(struct evsel *evsel, union perf_event *event)
{
struct perf_record_read *read_event = &event->read;
@@ -1348,6 +1363,9 @@ static int machines__deliver_event(struct machines *machines,
return tool->text_poke(tool, event, sample, machine);
case PERF_RECORD_AUX_OUTPUT_HW_ID:
return tool->aux_output_hw_id(tool, event, sample, machine);
+ case PERF_RECORD_CALLCHAIN_DEFERRED:
+ dump_deferred_callchain(evsel, event, sample);
+ return tool->callchain_deferred(tool, event, sample, evsel, machine);
default:
++evlist->stats.nr_unknown_events;
return -1;
diff --git a/tools/perf/util/tool.c b/tools/perf/util/tool.c
index 37bd8ac63b01..e1d60abb4e41 100644
--- a/tools/perf/util/tool.c
+++ b/tools/perf/util/tool.c
@@ -266,6 +266,7 @@ void perf_tool__init(struct perf_tool *tool, bool ordered_events)
tool->read = process_event_sample_stub;
tool->throttle = process_event_stub;
tool->unthrottle = process_event_stub;
+ tool->callchain_deferred = process_event_sample_stub;
tool->attr = process_event_synth_attr_stub;
tool->event_update = process_event_synth_event_update_stub;
tool->tracing_data = process_event_synth_tracing_data_stub;
diff --git a/tools/perf/util/tool.h b/tools/perf/util/tool.h
index db1c7642b0d1..9987bbde6d5e 100644
--- a/tools/perf/util/tool.h
+++ b/tools/perf/util/tool.h
@@ -42,7 +42,8 @@ enum show_feature_header {
struct perf_tool {
event_sample sample,
- read;
+ read,
+ callchain_deferred;
event_op mmap,
mmap2,
comm,
--
2.47.2
next prev parent reply other threads:[~2025-07-18 16:43 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-07-18 16:41 [PATCH v14 00/11] perf: Support the deferred unwinding infrastructure Steven Rostedt
2025-07-18 16:41 ` [PATCH v14 01/11] perf: Remove get_perf_callchain() init_nr argument Steven Rostedt
2025-07-18 16:41 ` [PATCH v14 02/11] perf: Have get_perf_callchain() return NULL if crosstask and user are set Steven Rostedt
2025-07-18 16:41 ` [PATCH v14 03/11] perf: Use current->flags & PF_KTHREAD|PF_USER_WORKER instead of current->mm == NULL Steven Rostedt
2025-07-18 16:41 ` [PATCH v14 04/11] perf: Simplify get_perf_callchain() user logic Steven Rostedt
2025-07-18 16:41 ` [PATCH v14 05/11] perf: Skip user unwind if the task is a kernel thread Steven Rostedt
2025-07-18 16:41 ` [PATCH v14 06/11] perf: Support deferred user callchains Steven Rostedt
2025-07-18 16:41 ` [PATCH v14 07/11] perf: Support deferred user callchains for per CPU events Steven Rostedt
2025-07-18 16:41 ` Steven Rostedt [this message]
2025-07-18 16:41 ` [PATCH v14 09/11] perf record: Enable defer_callchain for user callchains Steven Rostedt
2025-07-18 16:41 ` [PATCH v14 10/11] perf script: Display PERF_RECORD_CALLCHAIN_DEFERRED Steven Rostedt
2025-07-18 16:41 ` [PATCH v14 11/11] perf tools: Merge deferred user callchains Steven Rostedt
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20250718164324.423885737@kernel.org \
--to=rostedt@kernel.org \
--cc=acme@kernel.org \
--cc=akpm@linux-foundation.org \
--cc=andrii@kernel.org \
--cc=axboe@kernel.dk \
--cc=beaub@linux.microsoft.com \
--cc=bpf@vger.kernel.org \
--cc=fweimer@redhat.com \
--cc=indu.bhagat@oracle.com \
--cc=jemarch@gnu.org \
--cc=jolsa@kernel.org \
--cc=jpoimboe@kernel.org \
--cc=jremus@linux.ibm.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-trace-kernel@vger.kernel.org \
--cc=mathieu.desnoyers@efficios.com \
--cc=mhiramat@kernel.org \
--cc=mingo@kernel.org \
--cc=namhyung@kernel.org \
--cc=peterz@infradead.org \
--cc=sam@gentoo.org \
--cc=tglx@linutronix.de \
--cc=torvalds@linux-foundation.org \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).