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A cpumap stores an int per CPU, so its size is 4 times the number of CPUs in the cpumap. We can reduce the size of the int to an int16_t, saving 2 bytes per CPU in the map. Signed-off-by: Ian Rogers Reviewed-by: Tim Chen --- This change is on top of: https://lore.kernel.org/lkml/20241206044035.1062032-1-irogers@google.com/ --- tools/lib/perf/include/perf/cpumap.h | 3 ++- tools/perf/util/cpumap.c | 13 ++++++++----- tools/perf/util/env.c | 2 +- 3 files changed, 11 insertions(+), 7 deletions(-) diff --git a/tools/lib/perf/include/perf/cpumap.h b/tools/lib/perf/include/= perf/cpumap.h index cbb65e55fc67..760a9aae9884 100644 --- a/tools/lib/perf/include/perf/cpumap.h +++ b/tools/lib/perf/include/perf/cpumap.h @@ -4,10 +4,11 @@ =20 #include #include +#include =20 /** A wrapper around a CPU to avoid confusion with the perf_cpu_map's map'= s indices. */ struct perf_cpu { - int cpu; + int16_t cpu; }; =20 struct perf_cache { diff --git a/tools/perf/util/cpumap.c b/tools/perf/util/cpumap.c index 27094211edd8..85e224d8631b 100644 --- a/tools/perf/util/cpumap.c +++ b/tools/perf/util/cpumap.c @@ -427,7 +427,7 @@ static void set_max_cpu_num(void) { const char *mnt; char path[PATH_MAX]; - int ret =3D -1; + int max, ret =3D -1; =20 /* set up default */ max_cpu_num.cpu =3D 4096; @@ -444,10 +444,12 @@ static void set_max_cpu_num(void) goto out; } =20 - ret =3D get_max_num(path, &max_cpu_num.cpu); + ret =3D get_max_num(path, &max); if (ret) goto out; =20 + max_cpu_num.cpu =3D max; + /* get the highest present cpu number for a sparse allocation */ ret =3D snprintf(path, PATH_MAX, "%s/devices/system/cpu/present", mnt); if (ret >=3D PATH_MAX) { @@ -455,8 +457,9 @@ static void set_max_cpu_num(void) goto out; } =20 - ret =3D get_max_num(path, &max_present_cpu_num.cpu); - + ret =3D get_max_num(path, &max); + if (!ret) + max_present_cpu_num.cpu =3D max; out: if (ret) pr_err("Failed to read max cpus, using default of %d\n", max_cpu_num.cpu= ); @@ -606,7 +609,7 @@ size_t cpu_map__snprint(struct perf_cpu_map *map, char = *buf, size_t size) #define COMMA first ? "" : "," =20 for (i =3D 0; i < perf_cpu_map__nr(map) + 1; i++) { - struct perf_cpu cpu =3D { .cpu =3D INT_MAX }; + struct perf_cpu cpu =3D { .cpu =3D INT16_MAX }; bool last =3D i =3D=3D perf_cpu_map__nr(map); =20 if (!last) diff --git a/tools/perf/util/env.c b/tools/perf/util/env.c index e2843ca2edd9..f1d7d22e7e98 100644 --- a/tools/perf/util/env.c +++ b/tools/perf/util/env.c @@ -531,7 +531,7 @@ int perf_env__numa_node(struct perf_env *env, struct pe= rf_cpu cpu) =20 for (i =3D 0; i < env->nr_numa_nodes; i++) { nn =3D &env->numa_nodes[i]; - nr =3D max(nr, perf_cpu_map__max(nn->map).cpu); + nr =3D max(nr, (int)perf_cpu_map__max(nn->map).cpu); } =20 nr++; --=20 2.47.0.338.g60cca15819-goog