Re: [PATCH V3 2/5] perf header: Add die information in CPU topology

Arnaldo Carvalho de Melo
2019-06-06T19:12:25Z

Em Tue, Jun 04, 2019 at 03:50:41PM -0700, kan.liang@linux.intel.com escreveu:
> From: Kan Liang <kan.liang@linux.intel.com>
>
> With the new CPUID.1F, a new level type of CPU topology, 'die', is
> introduced. The 'die' information in CPU topology should be added in
> perf header.
>
> To be compatible with old perf.data, the patch checks the section size
> before reading the die information. The new info is added at the end of
> the cpu_topology section, the old perf tool ignores the extra data.
> It never reads data crossing the section boundary.
>
> The new perf tool with the patch can be used on legacy kernel. Add a
> new function has_die_topology() to check if die topology information is
> supported by kernel. The function only check X86 and CPU 0. Assuming
> other CPUs have same topology.

You're changing the header, how would a new tool handle an old perf.data
where this 'die_id' is not present? What about an old tool dealing with
a perf.data with this die_id?

I couldn't see any provision for that, am I missing something?

/me goes to read tools/perf/util/cputopo.c ...

Yeah, its just the description on the perf.data doc file that confused
me, I'll clarify that after finishing reviewing/applying this patchkit.

- Arnaldo

> Use similar method for core and socket to support die id and sibling
> dies string.
>
> Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
> ---
>
> No changes since V2.
>
> tools/perf/Documentation/perf.data-file-format.txt | 9 ++-
> tools/perf/util/cputopo.c | 76 +++++++++++++++--
> tools/perf/util/cputopo.h | 2 +
> tools/perf/util/env.c | 1 +
> tools/perf/util/env.h | 3 +
> tools/perf/util/header.c | 94 ++++++++++++++++++++--
> 6 files changed, 172 insertions(+), 13 deletions(-)
>
> diff --git a/tools/perf/Documentation/perf.data-file-format.txt b/tools/perf/Documentation/perf.data-file-format.txt
> index 6375e6f..0165e92 100644
> --- a/tools/perf/Documentation/perf.data-file-format.txt
> +++ b/tools/perf/Documentation/perf.data-file-format.txt
> @@ -153,7 +153,7 @@ struct {
>
> String lists defining the core and CPU threads topology.
> The string lists are followed by a variable length array
> -which contains core_id and socket_id of each cpu.
> +which contains core_id, die_id (for x86) and socket_id of each cpu.
> The number of entries can be determined by the size of the
> section minus the sizes of both string lists.
>
> @@ -162,14 +162,19 @@ struct {
> struct perf_header_string_list threads; /* Variable length */
> struct {
> uint32_t core_id;
> + uint32_t die_id;
> uint32_t socket_id;
> } cpus[nr]; /* Variable length records */
> };

- Arnaldo

> Example:
> - sibling cores : 0-3
> + sibling cores : 0-8
> + sibling dies : 0-3
> + sibling dies : 4-7
> sibling threads : 0-1
> sibling threads : 2-3
> + sibling threads : 4-5
> + sibling threads : 6-7
>
> HEADER_NUMA_TOPOLOGY = 14,
>
> diff --git a/tools/perf/util/cputopo.c b/tools/perf/util/cputopo.c
> index ece0710..85fa87f 100644
> --- a/tools/perf/util/cputopo.c
> +++ b/tools/perf/util/cputopo.c
> @@ -1,5 +1,6 @@
> // SPDX-License-Identifier: GPL-2.0
> #include <sys/param.h>
> +#include <sys/utsname.h>
> #include <inttypes.h>
> #include <api/fs/fs.h>
>
> @@ -8,9 +9,10 @@
> #include "util.h"
> #include "env.h"
>
> -
> #define CORE_SIB_FMT \
> "%s/devices/system/cpu/cpu%d/topology/core_siblings_list"
> +#define DIE_SIB_FMT \
> + "%s/devices/system/cpu/cpu%d/topology/die_cpus_list"
> #define THRD_SIB_FMT \
> "%s/devices/system/cpu/cpu%d/topology/thread_siblings_list"
> #define NODE_ONLINE_FMT \
> @@ -34,12 +36,12 @@ static int build_cpu_topology(struct cpu_topology *tp, int cpu)
> sysfs__mountpoint(), cpu);
> fp = fopen(filename, "r");
> if (!fp)
> - goto try_threads;
> + goto try_dies;
>
> sret = getline(&buf, &len, fp);
> fclose(fp);
> if (sret <= 0)
> - goto try_threads;
> + goto try_dies;
>
> p = strchr(buf, '\n');
> if (p)
> @@ -57,6 +59,37 @@ static int build_cpu_topology(struct cpu_topology *tp, int cpu)
> }
> ret = 0;
>
> +try_dies:
> + if (!tp->die_siblings)
> + goto try_threads;
> +
> + scnprintf(filename, MAXPATHLEN, DIE_SIB_FMT,
> + sysfs__mountpoint(), cpu);
> + fp = fopen(filename, "r");
> + if (!fp)
> + goto try_threads;
> +
> + sret = getline(&buf, &len, fp);
> + fclose(fp);
> + if (sret <= 0)
> + goto try_threads;
> +
> + p = strchr(buf, '\n');
> + if (p)
> + *p = '\0';
> +
> + for (i = 0; i < tp->die_sib; i++) {
> + if (!strcmp(buf, tp->die_siblings[i]))
> + break;
> + }
> + if (i == tp->die_sib) {
> + tp->die_siblings[i] = buf;
> + tp->die_sib++;
> + buf = NULL;
> + len = 0;
> + }
> + ret = 0;
> +
> try_threads:
> scnprintf(filename, MAXPATHLEN, THRD_SIB_FMT,
> sysfs__mountpoint(), cpu);
> @@ -98,21 +131,46 @@ void cpu_topology__delete(struct cpu_topology *tp)
> for (i = 0 ; i < tp->core_sib; i++)
> zfree(&tp->core_siblings[i]);
>
> + if (tp->die_sib) {
> + for (i = 0 ; i < tp->die_sib; i++)
> + zfree(&tp->die_siblings[i]);
> + }
> +
> for (i = 0 ; i < tp->thread_sib; i++)
> zfree(&tp->thread_siblings[i]);
>
> free(tp);
> }
>
> +static bool has_die_topology(void)
> +{
> + char filename[MAXPATHLEN];
> + struct utsname uts;
> +
> + if (uname(&uts) < 0)
> + return false;
> +
> + if (strncmp(uts.machine, "x86_64", 6))
> + return false;
> +
> + scnprintf(filename, MAXPATHLEN, DIE_SIB_FMT,
> + sysfs__mountpoint(), 0);
> + if (access(filename, F_OK) == -1)
> + return false;
> +
> + return true;
> +}
> +
> struct cpu_topology *cpu_topology__new(void)
> {
> struct cpu_topology *tp = NULL;
> void *addr;
> - u32 nr, i;
> + u32 nr, i, nr_addr;
> size_t sz;
> long ncpus;
> int ret = -1;
> struct cpu_map *map;
> + bool has_die = has_die_topology();
>
> ncpus = cpu__max_present_cpu();
>
> @@ -126,7 +184,11 @@ struct cpu_topology *cpu_topology__new(void)
> nr = (u32)(ncpus & UINT_MAX);
>
> sz = nr * sizeof(char *);
> - addr = calloc(1, sizeof(*tp) + 2 * sz);
> + if (has_die)
> + nr_addr = 3;
> + else
> + nr_addr = 2;
> + addr = calloc(1, sizeof(*tp) + nr_addr * sz);
> if (!addr)
> goto out_free;
>
> @@ -134,6 +196,10 @@ struct cpu_topology *cpu_topology__new(void)
> addr += sizeof(*tp);
> tp->core_siblings = addr;
> addr += sz;
> + if (has_die) {
> + tp->die_siblings = addr;
> + addr += sz;
> + }
> tp->thread_siblings = addr;
>
> for (i = 0; i < nr; i++) {
> diff --git a/tools/perf/util/cputopo.h b/tools/perf/util/cputopo.h
> index 47a97e7..bae2f1d 100644
> --- a/tools/perf/util/cputopo.h
> +++ b/tools/perf/util/cputopo.h
> @@ -7,8 +7,10 @@
>
> struct cpu_topology {
> u32 core_sib;
> + u32 die_sib;
> u32 thread_sib;
> char **core_siblings;
> + char **die_siblings;
> char **thread_siblings;
> };
>
> diff --git a/tools/perf/util/env.c b/tools/perf/util/env.c
> index 6a3eaf7..1cc7a18 100644
> --- a/tools/perf/util/env.c
> +++ b/tools/perf/util/env.c
> @@ -246,6 +246,7 @@ int perf_env__read_cpu_topology_map(struct perf_env *env)
> for (cpu = 0; cpu < nr_cpus; ++cpu) {
> env->cpu[cpu].core_id = cpu_map__get_core_id(cpu);
> env->cpu[cpu].socket_id = cpu_map__get_socket_id(cpu);
> + env->cpu[cpu].die_id = cpu_map__get_die_id(cpu);
> }
>
> env->nr_cpus_avail = nr_cpus;
> diff --git a/tools/perf/util/env.h b/tools/perf/util/env.h
> index 271a90b..d5d9865 100644
> --- a/tools/perf/util/env.h
> +++ b/tools/perf/util/env.h
> @@ -9,6 +9,7 @@
>
> struct cpu_topology_map {
> int socket_id;
> + int die_id;
> int core_id;
> };
>
> @@ -49,6 +50,7 @@ struct perf_env {
>
> int nr_cmdline;
> int nr_sibling_cores;
> + int nr_sibling_dies;
> int nr_sibling_threads;
> int nr_numa_nodes;
> int nr_memory_nodes;
> @@ -57,6 +59,7 @@ struct perf_env {
> char *cmdline;
> const char **cmdline_argv;
> char *sibling_cores;
> + char *sibling_dies;
> char *sibling_threads;
> char *pmu_mappings;
> struct cpu_topology_map *cpu;
> diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
> index 847ae51..6497625 100644
> --- a/tools/perf/util/header.c
> +++ b/tools/perf/util/header.c
> @@ -599,6 +599,27 @@ static int write_cpu_topology(struct feat_fd *ff,
> if (ret < 0)
> return ret;
> }
> +
> + if (!tp->die_sib)
> + goto done;
> +
> + ret = do_write(ff, &tp->die_sib, sizeof(tp->die_sib));
> + if (ret < 0)
> + goto done;
> +
> + for (i = 0; i < tp->die_sib; i++) {
> + ret = do_write_string(ff, tp->die_siblings[i]);
> + if (ret < 0)
> + goto done;
> + }
> +
> + for (j = 0; j < perf_env.nr_cpus_avail; j++) {
> + ret = do_write(ff, &perf_env.cpu[j].die_id,
> + sizeof(perf_env.cpu[j].die_id));
> + if (ret < 0)
> + return ret;
> + }
> +
> done:
> cpu_topology__delete(tp);
> return ret;
> @@ -1443,6 +1464,16 @@ static void print_cpu_topology(struct feat_fd *ff, FILE *fp)
> str += strlen(str) + 1;
> }
>
> + if (ph->env.nr_sibling_dies) {
> + nr = ph->env.nr_sibling_dies;
> + str = ph->env.sibling_dies;
> +
> + for (i = 0; i < nr; i++) {
> + fprintf(fp, "# sibling dies : %s\n", str);
> + str += strlen(str) + 1;
> + }
> + }
> +
> nr = ph->env.nr_sibling_threads;
> str = ph->env.sibling_threads;
>
> @@ -1451,12 +1482,28 @@ static void print_cpu_topology(struct feat_fd *ff, FILE *fp)
> str += strlen(str) + 1;
> }
>
> - if (ph->env.cpu != NULL) {
> - for (i = 0; i < cpu_nr; i++)
> - fprintf(fp, "# CPU %d: Core ID %d, Socket ID %d\n", i,
> - ph->env.cpu[i].core_id, ph->env.cpu[i].socket_id);
> - } else
> - fprintf(fp, "# Core ID and Socket ID information is not available\n");
> + if (ph->env.nr_sibling_dies) {
> + if (ph->env.cpu != NULL) {
> + for (i = 0; i < cpu_nr; i++)
> + fprintf(fp, "# CPU %d: Core ID %d, "
> + "Die ID %d, Socket ID %d\n",
> + i, ph->env.cpu[i].core_id,
> + ph->env.cpu[i].die_id,
> + ph->env.cpu[i].socket_id);
> + } else
> + fprintf(fp, "# Core ID, Die ID and Socket ID "
> + "information is not available\n");
> + } else {
> + if (ph->env.cpu != NULL) {
> + for (i = 0; i < cpu_nr; i++)
> + fprintf(fp, "# CPU %d: Core ID %d, "
> + "Socket ID %d\n",
> + i, ph->env.cpu[i].core_id,
> + ph->env.cpu[i].socket_id);
> + } else
> + fprintf(fp, "# Core ID and Socket ID "
> + "information is not available\n");
> + }
> }
>
> static void print_clockid(struct feat_fd *ff, FILE *fp)
> @@ -2214,6 +2261,7 @@ static int process_cpu_topology(struct feat_fd *ff, void *data __maybe_unused)
> goto free_cpu;
>
> ph->env.cpu[i].core_id = nr;
> + size += sizeof(u32);
>
> if (do_read_u32(ff, &nr))
> goto free_cpu;
> @@ -2225,6 +2273,40 @@ static int process_cpu_topology(struct feat_fd *ff, void *data __maybe_unused)
> }
>
> ph->env.cpu[i].socket_id = nr;
> + size += sizeof(u32);
> + }
> +
> + /*
> + * The header may be from old perf,
> + * which doesn't include die information.
> + */
> + if (ff->size <= size)
> + return 0;
> +
> + if (do_read_u32(ff, &nr))
> + return -1;
> +
> + ph->env.nr_sibling_dies = nr;
> + size += sizeof(u32);
> +
> + for (i = 0; i < nr; i++) {
> + str = do_read_string(ff);
> + if (!str)
> + goto error;
> +
> + /* include a NULL character at the end */
> + if (strbuf_add(&sb, str, strlen(str) + 1) < 0)
> + goto error;
> + size += string_size(str);
> + free(str);
> + }
> + ph->env.sibling_dies = strbuf_detach(&sb, NULL);
> +
> + for (i = 0; i < (u32)cpu_nr; i++) {
> + if (do_read_u32(ff, &nr))
> + goto free_cpu;
> +
> + ph->env.cpu[i].die_id = nr;
> }
>
> return 0;
> --
> 2.7.4

--

- Arnaldo