Re: [PATCH V2 5/5] perf mem: Clean up is_mem_loads_aux_event()

Leo Yan
2023-12-09T06:27:30Z

On Thu, Dec 07, 2023 at 11:23:38AM -0800, kan.liang@linux.intel.com wrote:
> From: Kan Liang <kan.liang@linux.intel.com>
>
> The aux_event can be retrieved from the perf_pmu now. Implement a
> generic support.
>
> Reviewed-by: Ian Rogers <irogers@google.com>
> Tested-by: Ravi Bangoria <ravi.bangoria@amd.com>
> Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
> ---
> tools/perf/arch/x86/util/mem-events.c | 23 ++++-------------------
> tools/perf/util/mem-events.c | 14 ++++++++++++--
> 2 files changed, 16 insertions(+), 21 deletions(-)
>
> diff --git a/tools/perf/arch/x86/util/mem-events.c b/tools/perf/arch/x86/util/mem-events.c
> index b776d849fc64..62df03e91c7e 100644
> --- a/tools/perf/arch/x86/util/mem-events.c
> +++ b/tools/perf/arch/x86/util/mem-events.c
> @@ -1,11 +1,9 @@
> // SPDX-License-Identifier: GPL-2.0
> -#include "util/pmu.h"
> -#include "util/pmus.h"
> -#include "util/env.h"
> -#include "map_symbol.h"
> -#include "mem-events.h"
> #include "linux/string.h"
> -#include "env.h"
> +#include "util/map_symbol.h"
> +#include "util/mem-events.h"
> +#include "mem-events.h"
> +
>
> #define MEM_LOADS_AUX 0x8203
>
> @@ -28,16 +26,3 @@ struct perf_mem_event perf_mem_events_amd[PERF_MEM_EVENTS__MAX] = {
> E(NULL, NULL, NULL, false, 0),
> E("mem-ldst", "%s//", NULL, false, 0),
> };
> -
> -bool is_mem_loads_aux_event(struct evsel *leader)
> -{
> - struct perf_pmu *pmu = perf_pmus__find("cpu");
> -
> - if (!pmu)
> - pmu = perf_pmus__find("cpu_core");
> -
> - if (pmu && !perf_pmu__have_event(pmu, "mem-loads-aux"))
> - return false;
> -
> - return leader->core.attr.config == MEM_LOADS_AUX;
> -}
> diff --git a/tools/perf/util/mem-events.c b/tools/perf/util/mem-events.c
> index 0d174f161034..d418320e52e3 100644
> --- a/tools/perf/util/mem-events.c
> +++ b/tools/perf/util/mem-events.c
> @@ -103,9 +103,19 @@ static const char *perf_pmu__mem_events_name(int i, struct perf_pmu *pmu)
> return NULL;
> }
>
> -__weak bool is_mem_loads_aux_event(struct evsel *leader __maybe_unused)
> +bool is_mem_loads_aux_event(struct evsel *leader)
> {
> - return false;
> + struct perf_pmu *pmu = leader->pmu;
> + struct perf_mem_event *e;
> +
> + if (!pmu || !pmu->mem_events)
> + return false;
> +
> + e = &pmu->mem_events[PERF_MEM_EVENTS__LOAD];
> + if (!e->aux_event)
> + return false;
> +
> + return leader->core.attr.config == e->aux_event;
> }

I am wandering if we need to set the field 'aux_event' for Arm SPE.

So a quesiton maybe is not relevant with this patch actually, we can
see is_mem_loads_aux_event() is invoked in the file util/record.c:

static struct evsel *evsel__read_sampler(struct evsel *evsel, struct evlist *evlist)
{
struct evsel *leader = evsel__leader(evsel);

if (evsel__is_aux_event(leader) || arch_topdown_sample_read(leader) ||
is_mem_loads_aux_event(leader)) {
...
}

return leader;
}

Has evsel__is_aux_event() covered the memory load aux event? If it's,
then is_mem_loads_aux_event() is not needed anymore.

Thanks,
Leo