[PATCH v2] perf: Increase MAX_NR_CPUS to 4096

[Kyle Meyer]

Systems have surpassed 2048 CPUs. Increase MAX_NR_CPUS to 4096.

Bitmaps declared with MAX_NR_CPUS bits will increase from 256B to 512B,
cpus_runtime will increase from 81960B to 163880B, and max_entries will
increase from 8192B to 16384B.

Signed-off-by: Kyle Meyer <kyle.meyer@xxxxxxx>
---

v1 -> v2:
  * Increase MAX_NR_CPUS in tools/perf/util/bpf_skel/kwork_top.bpf.c, as
    suggested by Ian Rogers.
  * https://lore.kernel.org/all/20241205165118.153148-1-kyle.meyer@xxxxxxx/

 tools/lib/perf/include/internal/cpumap.h | 2 +-
 tools/perf/perf.h                        | 2 +-
 tools/perf/util/bpf_skel/kwork_top.bpf.c | 4 +++-
 3 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/tools/lib/perf/include/internal/cpumap.h b/tools/lib/perf/include/internal/cpumap.h
index 49649eb51ce4..3cf28522004e 100644
--- a/tools/lib/perf/include/internal/cpumap.h
+++ b/tools/lib/perf/include/internal/cpumap.h
@@ -22,7 +22,7 @@ DECLARE_RC_STRUCT(perf_cpu_map) {
 };
 
 #ifndef MAX_NR_CPUS
-#define MAX_NR_CPUS	2048
+#define MAX_NR_CPUS	4096
 #endif
 
 struct perf_cpu_map *perf_cpu_map__alloc(int nr_cpus);
diff --git a/tools/perf/perf.h b/tools/perf/perf.h
index c004dd4e65a3..3cb40965549f 100644
--- a/tools/perf/perf.h
+++ b/tools/perf/perf.h
@@ -3,7 +3,7 @@
 #define _PERF_PERF_H
 
 #ifndef MAX_NR_CPUS
-#define MAX_NR_CPUS			2048
+#define MAX_NR_CPUS			4096
 #endif
 
 enum perf_affinity {
diff --git a/tools/perf/util/bpf_skel/kwork_top.bpf.c b/tools/perf/util/bpf_skel/kwork_top.bpf.c
index 594da91965a2..73e32e063030 100644
--- a/tools/perf/util/bpf_skel/kwork_top.bpf.c
+++ b/tools/perf/util/bpf_skel/kwork_top.bpf.c
@@ -18,7 +18,9 @@ enum kwork_class_type {
 };
 
 #define MAX_ENTRIES     102400
-#define MAX_NR_CPUS     2048
+#ifndef MAX_NR_CPUS
+#define MAX_NR_CPUS     4096
+#endif
 #define PF_KTHREAD      0x00200000
 #define MAX_COMMAND_LEN 16
 
-- 
2.35.3