> On 15 Sep 2025, at 8:37 PM, Adrian Hunter <adrian.hun...@intel.com> wrote:
>
> On 15/09/2025 10:27, Athira Rajeev wrote:
>> The powerpc PMU collecting Dispatch Trace Log (DTL) entries makes use of
>> AUX support in perf infrastructure. The PMU driver has the functionality
>> to collect trace entries in the aux buffer. On the tools side, this data
>> is made available as PERF_RECORD_AUXTRACE records. This record is
>> generated by "perf record" command. To enable the creation of
>> PERF_RECORD_AUXTRACE, add functions to initialize auxtrace records ie
>> "auxtrace_record__init()". Fill in fields for other callbacks like
>> info_priv_size, info_fill, free, recording options etc. Define
>> auxtrace_type as PERF_AUXTRACE_VPA_DTL. Add header file to define vpa
>> dtl pmu specific details.
>>
>> Signed-off-by: Athira Rajeev <atraj...@linux.ibm.com>
>> ---
>> Changelog:
>> Addressed review comments from Adrian:
>> - Return VPADTL_AUXTRACE_PRIV_SIZE in powerpc_vpadtl_info_priv_size
>> - Remove unused powerpc_vpadtl_parse_snapshot_options
>> - Some of the function parameters had "__maybe_unused", corrected it.
>> - Used PERF_AUXTRACE_VPA_DTL instead of PERF_AUXTRACE_VPA_PMU
>> - Moved powerpc_vpadtl_process_auxtrace_info to next patch
>>
>> tools/perf/arch/powerpc/util/Build | 1 +
>> tools/perf/arch/powerpc/util/auxtrace.c | 114 ++++++++++++++++++++++++
>> tools/perf/util/auxtrace.c | 1 +
>> tools/perf/util/auxtrace.h | 1 +
>> tools/perf/util/powerpc-vpadtl.h | 18 ++++
>> 5 files changed, 135 insertions(+)
>> create mode 100644 tools/perf/arch/powerpc/util/auxtrace.c
>> create mode 100644 tools/perf/util/powerpc-vpadtl.h
>>
>> diff --git a/tools/perf/arch/powerpc/util/Build
>> b/tools/perf/arch/powerpc/util/Build
>> index fdd6a77a3432..a5b0babd307e 100644
>> --- a/tools/perf/arch/powerpc/util/Build
>> +++ b/tools/perf/arch/powerpc/util/Build
>> @@ -10,3 +10,4 @@ perf-util-$(CONFIG_LIBDW) += skip-callchain-idx.o
>>
>> perf-util-$(CONFIG_LIBUNWIND) += unwind-libunwind.o
>> perf-util-$(CONFIG_LIBDW_DWARF_UNWIND) += unwind-libdw.o
>> +perf-util-$(CONFIG_AUXTRACE) += auxtrace.o
>> diff --git a/tools/perf/arch/powerpc/util/auxtrace.c
>> b/tools/perf/arch/powerpc/util/auxtrace.c
>> new file mode 100644
>> index 000000000000..803c582c0c6f
>> --- /dev/null
>> +++ b/tools/perf/arch/powerpc/util/auxtrace.c
>> @@ -0,0 +1,114 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * VPA support
>> + */
>> +
>> +#include <linux/kernel.h>
>> +#include <linux/types.h>
>> +#include <linux/bitops.h>
>> +#include <linux/log2.h>
>
> Are bitops.h and log2.h needed?
>
>> +#include <linux/string.h>
>> +#include <time.h>
>> +
>> +#include "../../util/cpumap.h"
>
> Is cpumap.h needed?
>
>> +#include "../../util/evsel.h"
>> +#include "../../util/evlist.h"
>> +#include "../../util/session.h"
>> +#include "../../util/util.h"
>> +#include "../../util/pmu.h"
>
> Is pmu.h needed?
>
>> +#include "../../util/debug.h"
>> +#include "../../util/auxtrace.h"
>> +#include "../../util/powerpc-vpadtl.h"
>> +#include "../../util/record.h"
>> +#include <internal/lib.h> // page_size
>> +
>> +#define KiB(x) ((x) * 1024)
>> +
>> +static int
>> +powerpc_vpadtl_recording_options(struct auxtrace_record *ar __maybe_unused,
>> + struct evlist *evlist __maybe_unused,
>> + struct record_opts *opts)
>> +{
>> + opts->full_auxtrace = true;
>> +
>> + /*
>> + * Set auxtrace_mmap_pages to minimum
>> + * two pages
>> + */
>> + if (!opts->auxtrace_mmap_pages) {
>> + opts->auxtrace_mmap_pages = KiB(128) / page_size;
>> + if (opts->mmap_pages == UINT_MAX)
>> + opts->mmap_pages = KiB(256) / page_size;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static size_t powerpc_vpadtl_info_priv_size(struct auxtrace_record *itr
>> __maybe_unused,
>> + struct evlist *evlist __maybe_unused)
>> +{
>> + return VPADTL_AUXTRACE_PRIV_SIZE;
>> +}
>> +
>> +static int
>> +powerpc_vpadtl_info_fill(struct auxtrace_record *itr __maybe_unused,
>> + struct perf_session *session __maybe_unused,
>> + struct perf_record_auxtrace_info *auxtrace_info,
>> + size_t priv_size __maybe_unused)
>> +{
>> + auxtrace_info->type = PERF_AUXTRACE_VPA_DTL;
>> +
>> + return 0;
>> +}
>> +
>> +static void powerpc_vpadtl_free(struct auxtrace_record *itr)
>> +{
>> + free(itr);
>> +}
>> +
>> +static u64 powerpc_vpadtl_reference(struct auxtrace_record *itr
>> __maybe_unused)
>> +{
>> + return 0;
>> +}
>> +
>> +struct auxtrace_record *auxtrace_record__init(struct evlist *evlist,
>> + int *err)
>> +{
>> + struct auxtrace_record *aux;
>> + struct evsel *pos;
>> + char *pmu_name;
>> + int found = 0;
>> +
>> + evlist__for_each_entry(evlist, pos) {
>> + pmu_name = strdup(pos->name);
>> + pmu_name = strtok(pmu_name, "/");
>> + if (strstarts(pmu_name, "vpa_dtl")) {
>
> pmu_name is leaked, but maybe it is not needed at all e.g.
>
> if (strstarts(pos->name, "vpa_dtl")) {
>
>> + found = 1;
>> + pos->needs_auxtrace_mmap = true;
>> + break;
>> + }
>> + }
>> +
>> + if (!found)
>> + return NULL;
>> +
>> + /*
>> + * To obtain the auxtrace buffer file descriptor, the auxtrace event
>> + * must come first.
>> + */
>> + evlist__to_front(pos->evlist, pos);
>> +
>> + aux = zalloc(sizeof(*aux));
>> + if (aux == NULL) {
>> + pr_debug("aux record is NULL\n");
>> + *err = -ENOMEM;
>> + return NULL;
>> + }
>> +
>> + aux->recording_options = powerpc_vpadtl_recording_options;
>> + aux->info_priv_size = powerpc_vpadtl_info_priv_size;
>> + aux->info_fill = powerpc_vpadtl_info_fill;
>> + aux->free = powerpc_vpadtl_free;
>> + aux->reference = powerpc_vpadtl_reference;
>> + return aux;
>> +}
>> diff --git a/tools/perf/util/auxtrace.c b/tools/perf/util/auxtrace.c
>> index ebd32f1b8f12..f294658bb948 100644
>> --- a/tools/perf/util/auxtrace.c
>> +++ b/tools/perf/util/auxtrace.c
>> @@ -1393,6 +1393,7 @@ int perf_event__process_auxtrace_info(struct
>> perf_session *session,
>> case PERF_AUXTRACE_HISI_PTT:
>> err = hisi_ptt_process_auxtrace_info(event, session);
>> break;
>> + case PERF_AUXTRACE_VPA_DTL:
>> case PERF_AUXTRACE_UNKNOWN:
>> default:
>> return -EINVAL;
>> diff --git a/tools/perf/util/auxtrace.h b/tools/perf/util/auxtrace.h
>> index f001cbb68f8e..e0a5b39fed12 100644
>> --- a/tools/perf/util/auxtrace.h
>> +++ b/tools/perf/util/auxtrace.h
>> @@ -50,6 +50,7 @@ enum auxtrace_type {
>> PERF_AUXTRACE_ARM_SPE,
>> PERF_AUXTRACE_S390_CPUMSF,
>> PERF_AUXTRACE_HISI_PTT,
>> + PERF_AUXTRACE_VPA_DTL,
>> };
>>
>> enum itrace_period_type {
>> diff --git a/tools/perf/util/powerpc-vpadtl.h
>> b/tools/perf/util/powerpc-vpadtl.h
>> new file mode 100644
>> index 000000000000..50a7aa24acbe
>> --- /dev/null
>> +++ b/tools/perf/util/powerpc-vpadtl.h
>> @@ -0,0 +1,18 @@
>> +/* SPDX-License-Identifier: GPL-2.0 */
>> +/*
>> + * VPA DTL PMU Support
>> + */
>> +
>> +#ifndef INCLUDE__PERF_POWERPC_VPADTL_H__
>> +#define INCLUDE__PERF_POWERPC_VPADTL_H__
>> +
>> +#define POWERPC_VPADTL_NAME "powerpc_vpadtl_"
>
> Never used
Hi Adrian
Thanks for reviewing the patchset and sharing your comments
I will address these changes in V3
Thanks
Athira
>
>> +
>> +enum {
>> + POWERPC_VPADTL_TYPE,
>> + VPADTL_AUXTRACE_PRIV_MAX,
>> +};
>> +
>> +#define VPADTL_AUXTRACE_PRIV_SIZE (VPADTL_AUXTRACE_PRIV_MAX * sizeof(u64))
>> +
>> +#endif
