From nobody Fri Oct 3 20:53:10 2025 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AEE6B30DECF; Mon, 25 Aug 2025 18:07:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756145268; cv=none; b=dSmcAI/q/qpqRJSl1QuVI1JmWGjE8U0KCIE+tcPooOeeIThz+pEh4eBGdmgoCoNs7GWo+QEU2BPgIpOg4nbtid0/i3N3u03eEvDUftr6tMbKH7CAnDoq2lB2lTiwfFp3dEY2MfQ3Vk22pzRoe8Xpr4xBJBTmzmcE4cExSPNZiyE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756145268; c=relaxed/simple; bh=9Rnqq37ziyd9TsWuAFkC6MYJHfruZ8hlQguidrQFd3k=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=WTXcYCSwCb7k7zzfQj7PEYS2VLkBN561cakKW0DFi+1520+JOR18C5JtjsPUHsY5V5RYhRUoRMbP5GiSVc37sZzlIUijSqQN5WPNu5cMedblZAvRBnyu2CvXV1YOek9QmtEluX3MLViyWoV2Vjm8QvQeX+VizEnQuk1ZclR5Y6g= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=gS8JzDIz; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="gS8JzDIz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4A52EC16AAE; Mon, 25 Aug 2025 18:07:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1756145268; bh=9Rnqq37ziyd9TsWuAFkC6MYJHfruZ8hlQguidrQFd3k=; h=Date:From:To:Cc:Subject:References:From; b=gS8JzDIzEdSj2aexctiE9Mq9Vy9eZ0/3isWBhmDLvan2TuHZlH/x4DnjG4pAiW6eF CcNDscCeC/d9mr8WIj4glE7IRsYJFxn+Jnq00vNxaS/ZE07ncX1+w7C//GBOtKDAzg ogg1cc1oyzG3l11EfQymUZ8NazRUAiyxKQ7qBLd7HY5Pgar1DK2VHIYWjCmybc9Qe0 yXEHWAWqg7gq7+qoaWpe4TT3DOrG7QGGMYOKklwqsxDDzg71WYzhIBBdfPkiVnUkug jfsiOIGGQ+xbSjlj2kyQULzlebfhOJw+KJJEXodoY68ZgzvRU05GAXJhbrBCXTQJVt CXay/8kuxwpMQ== Received: from rostedt by gandalf with local (Exim 4.98.2) (envelope-from ) id 1uqbbu-00000002n56-1Ybz; Mon, 25 Aug 2025 14:08:02 -0400 Message-ID: <20250825180802.223812079@kernel.org> User-Agent: quilt/0.68 Date: Mon, 25 Aug 2025 14:06:43 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, bpf@vger.kernel.org, x86@kernel.org Cc: Masami Hiramatsu , Mathieu Desnoyers , Josh Poimboeuf , Peter Zijlstra , Ingo Molnar , Jiri Olsa , Arnaldo Carvalho de Melo , Namhyung Kim , Thomas Gleixner , Andrii Nakryiko , Indu Bhagat , "Jose E. Marchesi" , Beau Belgrave , Jens Remus , Linus Torvalds , Andrew Morton , Jens Axboe , Florian Weimer , Sam James Subject: [PATCH v15 5/8] perf tools: Minimal CALLCHAIN_DEFERRED support References: <20250825180638.877627656@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Namhyung Kim 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 Signed-off-by: Josh Poimboeuf Signed-off-by: Steven Rostedt (Google) --- Changes since v14: https://lore.kernel.org/20250718164324.423885737@kernel.= org - Updated to use PERF_DEFERRED_ITEMS to find PERF_CONTEXT_USER_DEFERRED tools/lib/perf/include/perf/event.h | 8 ++++++++ tools/perf/util/event.c | 1 + tools/perf/util/evsel.c | 18 ++++++++++++++++++ tools/perf/util/machine.c | 1 + tools/perf/util/perf_event_attr_fprintf.c | 1 + tools/perf/util/sample.h | 4 +++- tools/perf/util/session.c | 18 ++++++++++++++++++ tools/perf/util/tool.c | 1 + tools/perf/util/tool.h | 3 ++- 9 files changed, 53 insertions(+), 2 deletions(-) diff --git a/tools/lib/perf/include/perf/event.h b/tools/lib/perf/include/p= erf/event.h index 6608f1e3701b..4af8cb238e27 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; }; =20 +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; @@ -522,6 +529,7 @@ 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 fcf44149feb2..4c92cc1a952c 100644 --- a/tools/perf/util/event.c +++ b/tools/perf/util/event.c @@ -61,6 +61,7 @@ static const char *perf_event__names[] =3D { [PERF_RECORD_CGROUP] =3D "CGROUP", [PERF_RECORD_TEXT_POKE] =3D "TEXT_POKE", [PERF_RECORD_AUX_OUTPUT_HW_ID] =3D "AUX_OUTPUT_HW_ID", + [PERF_RECORD_CALLCHAIN_DEFERRED] =3D "CALLCHAIN_DEFERRED", [PERF_RECORD_HEADER_ATTR] =3D "ATTR", [PERF_RECORD_HEADER_EVENT_TYPE] =3D "EVENT_TYPE", [PERF_RECORD_HEADER_TRACING_DATA] =3D "TRACING_DATA", diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c index d264c143b592..7512b9fb877d 100644 --- a/tools/perf/util/evsel.c +++ b/tools/perf/util/evsel.c @@ -3002,6 +3002,18 @@ int evsel__parse_sample(struct evsel *evsel, union p= erf_event *event, data->data_src =3D PERF_MEM_DATA_SRC_NONE; data->vcpu =3D -1; =20 + if (event->header.type =3D=3D PERF_RECORD_CALLCHAIN_DEFERRED) { + const u64 max_callchain_nr =3D UINT64_MAX / sizeof(u64); + + data->callchain =3D (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 !=3D PERF_RECORD_SAMPLE) { if (!evsel->core.attr.sample_id_all) return 0; @@ -3132,6 +3144,12 @@ int evsel__parse_sample(struct evsel *evsel, union p= erf_event *event, if (data->callchain->nr > max_callchain_nr) return -EFAULT; sz =3D data->callchain->nr * sizeof(u64); + if (evsel->core.attr.defer_callchain && + data->callchain->nr >=3D PERF_DEFERRED_ITEMS && + data->callchain->ips[data->callchain->nr - PERF_DEFERRED_ITEMS] =3D= =3D PERF_CONTEXT_USER_DEFERRED) { + data->deferred_callchain =3D true; + data->deferred_cookie =3D data->callchain->ips[data->callchain->nr - 1]; + } OVERFLOW_CHECK(array, sz, max_size); array =3D (void *)array + sz; } diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c index b5dd42588c91..841b711d970e 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 =3D PERF_RECORD_MISC_KERNEL; break; case PERF_CONTEXT_USER: + case PERF_CONTEXT_USER_DEFERRED: *cpumode =3D PERF_RECORD_MISC_USER; break; default: diff --git a/tools/perf/util/perf_event_attr_fprintf.c b/tools/perf/util/pe= rf_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_even= t_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); =20 PRINT_ATTRn("{ wakeup_events, wakeup_watermark }", wakeup_events, p_unsig= ned, false); PRINT_ATTRf(bp_type, p_unsigned); diff --git a/tools/perf/util/sample.h b/tools/perf/util/sample.h index fae834144ef4..68392e6298b7 100644 --- a/tools/perf/util/sample.h +++ b/tools/perf/util/sample.h @@ -106,7 +106,9 @@ struct perf_sample { u16 ins_lat; /** @weight3: On x86 holds retire_lat, on powerpc holds p_stage_cyc. */ u16 weight3; - 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 */ + u64 deferred_cookie; 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 26ae078278cd..a071006350f5 100644 --- a/tools/perf/util/session.c +++ b/tools/perf/util/session.c @@ -720,6 +720,7 @@ static perf_event__swap_op perf_event__swap_ops[] =3D { [PERF_RECORD_CGROUP] =3D perf_event__cgroup_swap, [PERF_RECORD_TEXT_POKE] =3D perf_event__text_poke_swap, [PERF_RECORD_AUX_OUTPUT_HW_ID] =3D perf_event__all64_swap, + [PERF_RECORD_CALLCHAIN_DEFERRED] =3D perf_event__all64_swap, [PERF_RECORD_HEADER_ATTR] =3D perf_event__hdr_attr_swap, [PERF_RECORD_HEADER_EVENT_TYPE] =3D perf_event__event_type_swap, [PERF_RECORD_HEADER_TRACING_DATA] =3D perf_event__tracing_data_swap, @@ -1123,6 +1124,20 @@ static void dump_sample(struct evsel *evsel, union p= erf_event *event, sample_read__printf(sample, evsel->core.attr.read_format); } =20 +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 =3D &event->read; @@ -1353,6 +1368,9 @@ static int machines__deliver_event(struct machines *m= achines, 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 e83c7ababc2a..8bf86af1ca90 100644 --- a/tools/perf/util/tool.c +++ b/tools/perf/util/tool.c @@ -279,6 +279,7 @@ void perf_tool__init(struct perf_tool *tool, bool order= ed_events) tool->read =3D process_event_sample_stub; tool->throttle =3D process_event_stub; tool->unthrottle =3D process_event_stub; + tool->callchain_deferred =3D process_event_sample_stub; tool->attr =3D process_event_synth_attr_stub; tool->event_update =3D process_event_synth_event_update_stub; tool->tracing_data =3D process_event_synth_tracing_data_stub; diff --git a/tools/perf/util/tool.h b/tools/perf/util/tool.h index 18b76ff0f26a..2676d84da80c 100644 --- a/tools/perf/util/tool.h +++ b/tools/perf/util/tool.h @@ -42,7 +42,8 @@ enum show_feature_header { =20 struct perf_tool { event_sample sample, - read; + read, + callchain_deferred; event_op mmap, mmap2, comm, --=20 2.50.1