Re: [PATCH v4 5/6] perf tools: Show memory region in perf-script subcommand

[Ian Rogers]

On Tue, Aug 11, 2026 at 10:34 AM Thomas Falcon <thomas.falcon@xxxxxxxxx> wrote:
>
> From: Dapeng Mi <dapeng1.mi@xxxxxxxxxxxxxxx>
>
> Show the memory region in perf-script subcommand. Memory region is found
> in the mem_region field of the memory information data source. This
> field was included with the introduction of support for the Off-module
> Response facility (OMR) [1] in Intel's Diamond Rapids and Nova Lake
> Architectures.
>
> An example of perf-script output with the new memory region field is shown
> below:
>
> random      10e6a100042 |OP LOAD|LVL L0 hit|SNP None|TLB L1 or L2 hit|LCK Yes|BLK  N/A|Region  N/A                           7f32ae64a2ec
> random    2411a68201042 |OP LOAD|LVL RAM hit|SNP Hit|TLB L1 or L2 hit|LCK No|BLK  N/A|Region  Mem-1                          561de7f8910a
> random      10e6a100042 |OP LOAD|LVL L0 hit|SNP None|TLB L1 or L2 hit|LCK Yes|BLK  N/A|Region  N/A                           7f32ae64a2d0
> random      20e6a100042 |OP LOAD|LVL L0 hit|SNP None|TLB L1 or L2 hit|LCK Yes|BLK  Data|Region  N/A                          7f32ae64a2d0
> random      20e6a100042 |OP LOAD|LVL L0 hit|SNP None|TLB L1 or L2 hit|LCK Yes|BLK  Data|Region  N/A                          7f32ae64a2d0
> random      10e6a100042 |OP LOAD|LVL L0 hit|SNP None|TLB L1 or L2 hit|LCK Yes|BLK  N/A|Region  N/A                           7f32ae64a2ec
> random      10e6a100042 |OP LOAD|LVL L0 hit|SNP None|TLB L1 or L2 hit|LCK Yes|BLK  N/A|Region  N/A                           7f32ae64a2d0
> random      10e6a100042 |OP LOAD|LVL L0 hit|SNP None|TLB L1 or L2 hit|LCK Yes|BLK  N/A|Region  N/A                           7f32ae64a2d0
> random    2411a68201042 |OP LOAD|LVL RAM hit|SNP Hit|TLB L1 or L2 hit|LCK No|BLK  N/A|Region  Mem-1                          561de7f8910a
> random      10e6a100042 |OP LOAD|LVL L0 hit|SNP None|TLB L1 or L2 hit|LCK Yes|BLK  N/A|Region  N/A                           7f32ae64a2ec
> random      10e6a100042 |OP LOAD|LVL L0 hit|SNP None|TLB L1 or L2 hit|LCK Yes|BLK  N/A|Region  N/A                           7f32ae64a2d0
>
> [1]: https://lore.kernel.org/all/20260114011750.350569-1-dapeng1.mi@xxxxxxxxxxxxxxx/
>
> Assisted-by: Sashiko:gemini-3.1-pro-preview
> Assisted-by: GitHub-Copilot:claude-opus-4-8
> Signed-off-by: Dapeng Mi <dapeng1.mi@xxxxxxxxxxxxxxx>
> Signed-off-by: Thomas Falcon <thomas.falcon@xxxxxxxxx>
> Link: https://lore.kernel.org/all/20260114011750.350569-1-dapeng1.mi@xxxxxxxxxxxxxxx/

Reviewed-by: Ian Rogers <irogers@xxxxxxxxxx>

Thanks,
Ian

> ---
> v4: Drop the global show-region flag; pass perf_session to
>     perf_script__meminfo_scnprintf() and gate the Region field
>     on the feature bit, with a pipe-mode fallback
>
> v3: make memory region reporting conditional on feature bit
> ---
>  tools/perf/builtin-script.c                   | 13 +--
>  tools/perf/util/mem-events.c                  | 86 ++++++++++++++++++-
>  tools/perf/util/mem-events.h                  |  4 +-
>  .../scripting-engines/trace-event-python.c    |  5 +-
>  4 files changed, 98 insertions(+), 10 deletions(-)
>
> diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
> index f91d8b1fbd01..410ccad56f99 100644
> --- a/tools/perf/builtin-script.c
> +++ b/tools/perf/builtin-script.c
> @@ -2078,11 +2078,12 @@ static int evlist__max_name_len(struct evlist *evlist)
>         return max;
>  }
>
> -static int data_src__fprintf(u64 data_src, FILE *fp)
> +static int data_src__fprintf(struct perf_session *session,
> +                            u64 data_src, FILE *fp)
>  {
>         struct mem_info *mi = mem_info__new();
> -       char decode[100];
> -       char out[100];
> +       char decode[200];
> +       char out[200];
>         static int maxlen;
>         int len;
>
> @@ -2090,10 +2091,10 @@ static int data_src__fprintf(u64 data_src, FILE *fp)
>                 return -ENOMEM;
>
>         mem_info__data_src(mi)->val = data_src;
> -       perf_script__meminfo_scnprintf(decode, 100, mi);
> +       perf_script__meminfo_scnprintf(decode, 200, mi, session);
>         mem_info__put(mi);
>
> -       len = scnprintf(out, 100, "%16" PRIx64 " %s", data_src, decode);
> +       len = scnprintf(out, 200, "%16" PRIx64 " %s", data_src, decode);
>         if (maxlen < len)
>                 maxlen = len;
>
> @@ -2487,7 +2488,7 @@ static void process_event(struct perf_script *script,
>                 perf_sample__fprintf_addr(sample, thread, evsel, fp);
>
>         if (PRINT_FIELD(DATA_SRC))
> -               data_src__fprintf(sample->data_src, fp);
> +               data_src__fprintf(evsel__session(evsel), sample->data_src, fp);
>
>         if (PRINT_FIELD(WEIGHT))
>                 fprintf(fp, "%16" PRIu64, sample->weight);
> diff --git a/tools/perf/util/mem-events.c b/tools/perf/util/mem-events.c
> index 4fd48fd20055..8ce4996cad8d 100644
> --- a/tools/perf/util/mem-events.c
> +++ b/tools/perf/util/mem-events.c
> @@ -604,8 +604,77 @@ int perf_mem__blk_scnprintf(char *out, size_t sz, const struct mem_info *mem_inf
>         return l;
>  }
>
> -int perf_script__meminfo_scnprintf(char *out, size_t sz, const struct mem_info *mem_info)
> +static int perf_mem__region_scnprintf(char *out, size_t sz, const struct mem_info *mem_info)
>  {
> +       size_t l = 0;
> +       u64 mem = PERF_MEM_REGION_NA;
> +
> +       sz -= 1; /* -1 for null termination */
> +       out[0] = '\0';
> +
> +       if (mem_info)
> +               mem = mem_info__const_data_src(mem_info)->mem_region;
> +
> +       switch (mem) {
> +       case PERF_MEM_REGION_NA:
> +       case PERF_MEM_REGION_RSVD:
> +               l += scnprintf(out + l, sz - l, "N/A");
> +               break;
> +       case PERF_MEM_REGION_L_SHARE:
> +               l += scnprintf(out + l, sz - l, "Local-shared-cache");
> +               break;
> +       case PERF_MEM_REGION_L_NON_SHARE:
> +               l += scnprintf(out + l, sz - l, "Local-non-shared-cache");
> +               break;
> +       case PERF_MEM_REGION_O_IO:
> +               l += scnprintf(out + l, sz - l, "Other-IO");
> +               break;
> +       case PERF_MEM_REGION_O_SHARE:
> +               l += scnprintf(out + l, sz - l, "Other-shared-cache");
> +               break;
> +       case PERF_MEM_REGION_O_NON_SHARE:
> +               l += scnprintf(out + l, sz - l, "Other-non-shared-cache");
> +               break;
> +       case PERF_MEM_REGION_MMIO:
> +               l += scnprintf(out + l, sz - l, "MMIO");
> +               break;
> +       case PERF_MEM_REGION_MEM0:
> +               l += scnprintf(out + l, sz - l, "Mem-0");
> +               break;
> +       case PERF_MEM_REGION_MEM1:
> +               l += scnprintf(out + l, sz - l, "Mem-1");
> +               break;
> +       case PERF_MEM_REGION_MEM2:
> +               l += scnprintf(out + l, sz - l, "Mem-2");
> +               break;
> +       case PERF_MEM_REGION_MEM3:
> +               l += scnprintf(out + l, sz - l, "Mem-3");
> +               break;
> +       case PERF_MEM_REGION_MEM4:
> +               l += scnprintf(out + l, sz - l, "Mem-4");
> +               break;
> +       case PERF_MEM_REGION_MEM5:
> +               l += scnprintf(out + l, sz - l, "Mem-5");
> +               break;
> +       case PERF_MEM_REGION_MEM6:
> +               l += scnprintf(out + l, sz - l, "Mem-6");
> +               break;
> +       case PERF_MEM_REGION_MEM7:
> +               l += scnprintf(out + l, sz - l, "Mem-7");
> +               break;
> +       default:
> +               l += scnprintf(out + l, sz - l, "N/A");
> +               break;
> +       }
> +
> +       return l;
> +}
> +
> +int perf_script__meminfo_scnprintf(char *out, size_t sz,
> +                                  const struct mem_info *mem_info,
> +                                  struct perf_session *session)
> +{
> +       struct perf_env *env;
>         int i = 0;
>
>         i += scnprintf(out, sz, "|OP ");
> @@ -620,6 +689,21 @@ int perf_script__meminfo_scnprintf(char *out, size_t sz, const struct mem_info *
>         i += perf_mem__lck_scnprintf(out + i, sz - i, mem_info);
>         i += scnprintf(out + i, sz - i, "|BLK ");
>         i += perf_mem__blk_scnprintf(out + i, sz - i, mem_info);
> +       if (session) {
> +               /*
> +                * In case the feature bits are not available, as in
> +                * pipe mode, fallback to checking for the existence of
> +                * memory ranges
> +                */
> +               env = perf_session__env(session);
> +               if ((env && session->data->is_pipe && env->nr_memory_ranges) ||
> +                   perf_header__has_feat(&session->header,
> +                                         HEADER_MEMORY_RANGES)) {
> +                       i += scnprintf(out + i, sz - i, "|Region ");
> +                       i += perf_mem__region_scnprintf(out + i, sz - i,
> +                                                       mem_info);
> +               }
> +       }
>
>         return i;
>  }
> diff --git a/tools/perf/util/mem-events.h b/tools/perf/util/mem-events.h
> index daa22748f9fe..4ebb8109fc3c 100644
> --- a/tools/perf/util/mem-events.h
> +++ b/tools/perf/util/mem-events.h
> @@ -4,6 +4,7 @@
>
>  #include <stdbool.h>
>  #include <linux/types.h>
> +#include "session.h"
>
>  struct perf_mem_event {
>         bool            supported;
> @@ -47,7 +48,8 @@ int perf_mem__snp_scnprintf(char *out, size_t sz, const struct mem_info *mem_inf
>  int perf_mem__lck_scnprintf(char *out, size_t sz, const struct mem_info *mem_info);
>  int perf_mem__blk_scnprintf(char *out, size_t sz, const struct mem_info *mem_info);
>
> -int perf_script__meminfo_scnprintf(char *bf, size_t size, const struct mem_info *mem_info);
> +int perf_script__meminfo_scnprintf(char *bf, size_t size, const struct mem_info *mem_info,
> +                                  struct perf_session *session);
>
>  struct c2c_stats {
>         u32     nr_entries;
> diff --git a/tools/perf/util/scripting-engines/trace-event-python.c b/tools/perf/util/scripting-engines/trace-event-python.c
> index 8f832ae316ca..e359fe529586 100644
> --- a/tools/perf/util/scripting-engines/trace-event-python.c
> +++ b/tools/perf/util/scripting-engines/trace-event-python.c
> @@ -694,8 +694,9 @@ static void set_sample_read_in_dict(PyObject *dict_sample, struct perf_sample *s
>  static void set_sample_datasrc_in_dict(PyObject *dict,
>                                       struct perf_sample *sample)
>  {
> +       struct perf_session *session = evsel__session(sample->evsel);
>         struct mem_info *mi = mem_info__new();
> -       char decode[100];
> +       char decode[200];
>
>         if (!mi)
>                 Py_FatalError("couldn't create mem-info");
> @@ -704,7 +705,7 @@ static void set_sample_datasrc_in_dict(PyObject *dict,
>                         PyLong_FromUnsignedLongLong(sample->data_src));
>
>         mem_info__data_src(mi)->val = sample->data_src;
> -       perf_script__meminfo_scnprintf(decode, 100, mi);
> +       perf_script__meminfo_scnprintf(decode, 200, mi, session);
>         mem_info__put(mi);
>
>         pydict_set_item_string_decref(dict, "datasrc_decode",
> --
> 2.55.0
>