[PATCH V2 2/6] tools/perf: process auxtrace events and display in perf report -D
Adrian Hunter
adrian.hunter at intel.com
Tue Sep 16 01:08:10 AEST 2025
On 15/09/2025 10:27, Athira Rajeev wrote:
> Add vpa dtl pmu auxtrace process function for "perf report -D".
> The auxtrace event processing functions are defined in file
> "util/powerpc-vpadtl.c". Data structures used includes "struct
> powerpc_vpadtl_queue", "struct powerpc_vpadtl" to store the auxtrace
> buffers in queue. Different PERF_RECORD_XXX are generated
> during recording. PERF_RECORD_AUXTRACE_INFO is processed first
> since it is of type perf_user_event_type and perf session event
> delivers perf_session__process_user_event() first. Define function
> powerpc_vpadtl_process_auxtrace_info() to handle the processing of
> PERF_RECORD_AUXTRACE_INFO records. In this function, initialize
> the aux buffer queues using auxtrace_queues__init(). Setup the
> required infrastructure for aux data processing. The data is collected
> per CPU and auxtrace_queue is created for each CPU.
>
> Define powerpc_vpadtl_process_event() function to process
> PERF_RECORD_AUXTRACE records. In this, add the event to queue using
> auxtrace_queues__add_event() and process the buffer in
> powerpc_vpadtl_dump_event(). The first entry in the buffer with
> timebase as zero has boot timebase and frequency. Remaining data is of
> format for "struct powerpc_vpadtl_entry". Define the translation for
> dispatch_reasons and preempt_reasons, report this when dump trace is
> invoked via powerpc_vpadtl_dump()
>
> Sample output:
>
> ./perf record -a -e sched:*,vpa_dtl/dtl_all/ -c 1000000000 sleep 1
> [ perf record: Woken up 1 times to write data ]
> [ perf record: Captured and wrote 0.300 MB perf.data ]
>
> ./perf report -D
>
> 0 0 0x39b10 [0x30]: PERF_RECORD_AUXTRACE size: 0x690 offset: 0 ref: 0 idx: 0 tid: -1 cpu: 0
> .
> . ... VPA DTL PMU data: size 1680 bytes, entries is 35
> . 00000000: boot_tb: 21349649546353231, tb_freq: 512000000
> . 00000030: dispatch_reason:decrementer interrupt, preempt_reason:H_CEDE, enqueue_to_dispatch_time:7064, ready_to_enqueue_time:187, waiting_to_ready_time:6611773
> . 00000060: dispatch_reason:priv doorbell, preempt_reason:H_CEDE, enqueue_to_dispatch_time:146, ready_to_enqueue_time:0, waiting_to_ready_time:15359437
> . 00000090: dispatch_reason:decrementer interrupt, preempt_reason:H_CEDE, enqueue_to_dispatch_time:4868, ready_to_enqueue_time:232, waiting_to_ready_time:5100709
> . 000000c0: dispatch_reason:priv doorbell, preempt_reason:H_CEDE, enqueue_to_dispatch_time:179, ready_to_enqueue_time:0, waiting_to_ready_time:30714243
> . 000000f0: dispatch_reason:priv doorbell, preempt_reason:H_CEDE, enqueue_to_dispatch_time:197, ready_to_enqueue_time:0, waiting_to_ready_time:15350648
> . 00000120: dispatch_reason:priv doorbell, preempt_reason:H_CEDE, enqueue_to_dispatch_time:213, ready_to_enqueue_time:0, waiting_to_ready_time:15353446
> . 00000150: dispatch_reason:priv doorbell, preempt_reason:H_CEDE, enqueue_to_dispatch_time:212, ready_to_enqueue_time:0, waiting_to_ready_time:15355126
> . 00000180: dispatch_reason:decrementer interrupt, preempt_reason:H_CEDE, enqueue_to_dispatch_time:6368, ready_to_enqueue_time:164, waiting_to_ready_time:5104665
>
> Signed-off-by: Athira Rajeev <atrajeev at linux.ibm.com>
> ---
> Changelog:
> Addressed review comments from Adrian
> - Renamed dtl_entry to powerpc_vpadtl_entry in util/event.h
> - Removed unused #includes in powerpc-vpadtl.c
> - Added helper session_to_vpa to get "struct powerpc_vpadtl"
> - Updated auxtrace_queues__add_event only for piped data
> - Used zfree to free "struct powerpc_vpadtl_queue"
>
> tools/perf/util/Build | 1 +
> tools/perf/util/auxtrace.c | 3 +
> tools/perf/util/event.h | 16 ++
> tools/perf/util/powerpc-vpadtl.c | 263 +++++++++++++++++++++++++++++++
> tools/perf/util/powerpc-vpadtl.h | 7 +
> 5 files changed, 290 insertions(+)
> create mode 100644 tools/perf/util/powerpc-vpadtl.c
>
> diff --git a/tools/perf/util/Build b/tools/perf/util/Build
> index 4959e7a990e4..5ead46dc98e7 100644
> --- a/tools/perf/util/Build
> +++ b/tools/perf/util/Build
> @@ -136,6 +136,7 @@ perf-util-$(CONFIG_AUXTRACE) += arm-spe-decoder/
> perf-util-$(CONFIG_AUXTRACE) += hisi-ptt.o
> perf-util-$(CONFIG_AUXTRACE) += hisi-ptt-decoder/
> perf-util-$(CONFIG_AUXTRACE) += s390-cpumsf.o
> +perf-util-$(CONFIG_AUXTRACE) += powerpc-vpadtl.o
>
> ifdef CONFIG_LIBOPENCSD
> perf-util-$(CONFIG_AUXTRACE) += cs-etm.o
> diff --git a/tools/perf/util/auxtrace.c b/tools/perf/util/auxtrace.c
> index f294658bb948..6d10f3d61ff8 100644
> --- a/tools/perf/util/auxtrace.c
> +++ b/tools/perf/util/auxtrace.c
> @@ -55,6 +55,7 @@
> #include "hisi-ptt.h"
> #include "s390-cpumsf.h"
> #include "util/mmap.h"
> +#include "powerpc-vpadtl.h"
>
> #include <linux/ctype.h>
> #include "symbol/kallsyms.h"
> @@ -1394,6 +1395,8 @@ int perf_event__process_auxtrace_info(struct perf_session *session,
> err = hisi_ptt_process_auxtrace_info(event, session);
> break;
> case PERF_AUXTRACE_VPA_DTL:
> + err = powerpc_vpadtl_process_auxtrace_info(event, session);
> + break;
> case PERF_AUXTRACE_UNKNOWN:
> default:
> return -EINVAL;
> diff --git a/tools/perf/util/event.h b/tools/perf/util/event.h
> index e40d16d3246c..7ba208ae86fd 100644
> --- a/tools/perf/util/event.h
> +++ b/tools/perf/util/event.h
> @@ -254,6 +254,22 @@ struct perf_synth_intel_iflag_chg {
> u64 branch_ip; /* If via_branch */
> };
>
> +/*
> + * The powerpc VPA DTL entries are of below format
> + */
> +struct powerpc_vpadtl_entry {
> + u8 dispatch_reason;
> + u8 preempt_reason;
> + u16 processor_id;
> + u32 enqueue_to_dispatch_time;
> + u32 ready_to_enqueue_time;
> + u32 waiting_to_ready_time;
> + u64 timebase;
> + u64 fault_addr;
> + u64 srr0;
> + u64 srr1;
> +};
> +
> static inline void *perf_synth__raw_data(void *p)
> {
> return p + 4;
> diff --git a/tools/perf/util/powerpc-vpadtl.c b/tools/perf/util/powerpc-vpadtl.c
> new file mode 100644
> index 000000000000..2e8488a3dbd7
> --- /dev/null
> +++ b/tools/perf/util/powerpc-vpadtl.c
> @@ -0,0 +1,263 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * VPA DTL PMU support
> + */
> +
> +#include <inttypes.h>
> +#include "color.h"
> +#include "evlist.h"
> +#include "session.h"
Should really also:
#include "auxtrace.h"
#include "data.h"
#include "machine.h"
> +#include "debug.h"
> +#include "powerpc-vpadtl.h"
> +
> +/*
> + * Structure to save the auxtrace queue
> + */
> +struct powerpc_vpadtl {
> + struct auxtrace auxtrace;
> + struct auxtrace_queues queues;
> + struct auxtrace_heap heap;
> + u32 auxtrace_type;
> + struct perf_session *session;
> + struct machine *machine;
> + u32 pmu_type;
> +};
> +
> +struct boottb_freq {
> + u64 boot_tb;
> + u64 tb_freq;
> + u64 timebase;
> + u64 padded[3];
> +};
> +
> +struct powerpc_vpadtl_queue {
> + struct powerpc_vpadtl *vpa;
> + unsigned int queue_nr;
> + struct auxtrace_buffer *buffer;
> + struct thread *thread;
> + bool on_heap;
> + bool done;
> + pid_t pid;
> + pid_t tid;
> + int cpu;
> +};
> +
> +const char *dispatch_reasons[11] = {
> + "external_interrupt",
> + "firmware_internal_event",
> + "H_PROD",
> + "decrementer_interrupt",
> + "system_reset",
> + "firmware_internal_event",
> + "conferred_cycles",
> + "time_slice",
> + "virtual_memory_page_fault",
> + "expropriated_adjunct",
> + "priv_doorbell"};
> +
> +const char *preempt_reasons[10] = {
> + "unused",
> + "firmware_internal_event",
> + "H_CEDE",
> + "H_CONFER",
> + "time_slice",
> + "migration_hibernation_page_fault",
> + "virtual_memory_page_fault",
> + "H_CONFER_ADJUNCT",
> + "hcall_adjunct",
> + "HDEC_adjunct"};
> +
> +#define dtl_entry_size sizeof(struct powerpc_vpadtl_entry)
> +
> +/*
> + * Function to dump the dispatch trace data when perf report
> + * is invoked with -D
> + */
> +static void powerpc_vpadtl_dump(struct powerpc_vpadtl *vpa __maybe_unused,
> + unsigned char *buf, size_t len)
> +{
> + struct powerpc_vpadtl_entry *dtl;
> + int pkt_len, pos = 0;
> + const char *color = PERF_COLOR_BLUE;
> +
> + color_fprintf(stdout, color,
> + ". ... VPA DTL PMU data: size %zu bytes, entries is %zu\n",
> + len, len/dtl_entry_size);
> +
> + if (len % dtl_entry_size)
> + len = len - (len % dtl_entry_size);
> +
> + while (len) {
> + pkt_len = dtl_entry_size;
> + printf(".");
> + color_fprintf(stdout, color, " %08x: ", pos);
> + dtl = (struct powerpc_vpadtl_entry *)buf;
> + if (dtl->timebase != 0) {
> + printf("dispatch_reason:%s, preempt_reason:%s, enqueue_to_dispatch_time:%d,"
> + "ready_to_enqueue_time:%d, waiting_to_ready_time:%d\n",
> + dispatch_reasons[dtl->dispatch_reason], preempt_reasons[dtl->preempt_reason],\
> + be32_to_cpu(dtl->enqueue_to_dispatch_time),\
> + be32_to_cpu(dtl->ready_to_enqueue_time), be32_to_cpu(dtl->waiting_to_ready_time));
Better if these lines were 100 columns or less
> + } else {
> + struct boottb_freq *boot_tb = (struct boottb_freq *)buf;
> +
> + printf("boot_tb: %" PRIu64 ", tb_freq: %" PRIu64 "\n", boot_tb->boot_tb, boot_tb->tb_freq);
Better if this lines was 100 columns or less
> + }
> +
> + pos += pkt_len;
> + buf += pkt_len;
> + len -= pkt_len;
> + }
> +}
> +
> +static struct powerpc_vpadtl *session_to_vpa(struct perf_session *session)
> +{
> + return container_of(session->auxtrace, struct powerpc_vpadtl, auxtrace);
> +}
> +
> +static void powerpc_vpadtl_dump_event(struct powerpc_vpadtl *vpa, unsigned char *buf,
> + size_t len)
> +{
> + printf(".\n");
> + powerpc_vpadtl_dump(vpa, buf, len);
> +}
> +
> +static int powerpc_vpadtl_process_event(struct perf_session *session __maybe_unused,
> + union perf_event *event __maybe_unused,
> + struct perf_sample *sample __maybe_unused,
> + const struct perf_tool *tool __maybe_unused)
> +{
> + return 0;
> +}
> +
> +/*
> + * Process PERF_RECORD_AUXTRACE records
> + */
> +static int powerpc_vpadtl_process_auxtrace_event(struct perf_session *session,
> + union perf_event *event,
> + const struct perf_tool *tool __maybe_unused)
> +{
> + struct powerpc_vpadtl *vpa = session_to_vpa(session);
> + struct auxtrace_buffer *buffer;
> + int fd = perf_data__fd(session->data);
> + off_t data_offset;
> + int err;
> +
> + if (!dump_trace)
> + return 0;
> +
> + if (perf_data__is_pipe(session->data)) {
> + data_offset = 0;
> + } else {
> + data_offset = lseek(fd, 0, SEEK_CUR);
> + if (data_offset == -1)
> + return -errno;
> + }
> +
> + err = auxtrace_queues__add_event(&vpa->queues, session, event,
> + data_offset, &buffer);
> +
> + if (err)
> + return err;
> +
> + /* Dump here now we have copied a piped trace out of the pipe */
> + if (auxtrace_buffer__get_data(buffer, fd)) {
> + powerpc_vpadtl_dump_event(vpa, buffer->data, buffer->size);
> + auxtrace_buffer__put_data(buffer);
> + }
> +
> + return 0;
> +}
> +
> +static int powerpc_vpadtl_flush(struct perf_session *session __maybe_unused,
> + const struct perf_tool *tool __maybe_unused)
> +{
> + return 0;
> +}
> +
> +static void powerpc_vpadtl_free_events(struct perf_session *session)
> +{
> + struct powerpc_vpadtl *vpa = session_to_vpa(session);
> + struct auxtrace_queues *queues = &vpa->queues;
> + struct powerpc_vpadtl_queue *vpaq;
> +
> + unsigned int i;
> +
> + for (i = 0; i < queues->nr_queues; i++) {
Modern style allows int decl. inside for() e.g.
for (int i = 0; i < queues->nr_queues; i++) {
> + vpaq = queues->queue_array[i].priv;
> + if (vpaq)
> + zfree(&vpaq);
free() can handle NULL, so vpaq not needed, just
zfree(&queues->queue_array[i].priv);
> + }
> +
> + auxtrace_queues__free(queues);
> +}
> +
> +static void powerpc_vpadtl_free(struct perf_session *session)
> +{
> + struct powerpc_vpadtl *vpa = session_to_vpa(session);
> +
> + auxtrace_heap__free(&vpa->heap);
> + powerpc_vpadtl_free_events(session);
> + session->auxtrace = NULL;
> + free(vpa);
> +}
> +
> +static const char * const powerpc_vpadtl_info_fmts[] = {
> + [POWERPC_VPADTL_TYPE] = " PMU Type %"PRId64"\n",
> +};
> +
> +static void powerpc_vpadtl_print_info(__u64 *arr)
> +{
> + if (!dump_trace)
> + return;
> +
> + fprintf(stdout, powerpc_vpadtl_info_fmts[POWERPC_VPADTL_TYPE], arr[POWERPC_VPADTL_TYPE]);
> +}
> +
> +/*
> + * Process the PERF_RECORD_AUXTRACE_INFO records and setup
> + * the infrastructure to process auxtrace events. PERF_RECORD_AUXTRACE_INFO
> + * is processed first since it is of type perf_user_event_type.
> + * Initialise the aux buffer queues using auxtrace_queues__init().
> + * auxtrace_queue is created for each CPU.
> + */
> +int powerpc_vpadtl_process_auxtrace_info(union perf_event *event,
> + struct perf_session *session)
> +{
> + struct perf_record_auxtrace_info *auxtrace_info = &event->auxtrace_info;
> + size_t min_sz = sizeof(u64) * POWERPC_VPADTL_TYPE;
> + struct powerpc_vpadtl *vpa;
> + int err;
> +
> + if (auxtrace_info->header.size < sizeof(struct perf_record_auxtrace_info) +
> + min_sz)
> + return -EINVAL;
> +
> + vpa = zalloc(sizeof(struct powerpc_vpadtl));
> + if (!vpa)
> + return -ENOMEM;
> +
> + err = auxtrace_queues__init(&vpa->queues);
> + if (err)
> + goto err_free;
> +
> + vpa->session = session;
> + vpa->machine = &session->machines.host; /* No kvm support */
> + vpa->auxtrace_type = auxtrace_info->type;
> + vpa->pmu_type = auxtrace_info->priv[POWERPC_VPADTL_TYPE];
> +
> + vpa->auxtrace.process_event = powerpc_vpadtl_process_event;
> + vpa->auxtrace.process_auxtrace_event = powerpc_vpadtl_process_auxtrace_event;
> + vpa->auxtrace.flush_events = powerpc_vpadtl_flush;
> + vpa->auxtrace.free_events = powerpc_vpadtl_free_events;
> + vpa->auxtrace.free = powerpc_vpadtl_free;
> + session->auxtrace = &vpa->auxtrace;
> +
> + powerpc_vpadtl_print_info(&auxtrace_info->priv[0]);
> +
> + return 0;
> +
> +err_free:
> + free(vpa);
> + return err;
> +}
> diff --git a/tools/perf/util/powerpc-vpadtl.h b/tools/perf/util/powerpc-vpadtl.h
> index 50a7aa24acbe..aa76f5beac2c 100644
> --- a/tools/perf/util/powerpc-vpadtl.h
> +++ b/tools/perf/util/powerpc-vpadtl.h
> @@ -15,4 +15,11 @@ enum {
>
> #define VPADTL_AUXTRACE_PRIV_SIZE (VPADTL_AUXTRACE_PRIV_MAX * sizeof(u64))
>
> +union perf_event;
> +struct perf_session;
> +struct perf_pmu;
> +
> +int powerpc_vpadtl_process_auxtrace_info(union perf_event *event,
> + struct perf_session *session);
> +
> #endif
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