perf record: Adapt affinity to machines with #CPUs > 1K

Use struct mmap_cpu_mask type for the tool's thread and mmap data
buffers to overcome current 1024 CPUs mask size limitation of cpu_set_t
type.

Currently glibc's cpu_set_t type has an internal mask size limit of 1024
CPUs.

Moving to the 'struct mmap_cpu_mask' type allows overcoming that limit.

The tools bitmap API is used to manipulate objects of 'struct mmap_cpu_mask'
type.

Committer notes:

To print the 'nbits' struct member we must use %zd, since it is a
size_t, this fixes the build in some toolchains/arches.

Reported-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/96d7e2ff-ce8b-c1e0-d52c-aa59ea96f0ea@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 22 insertions, 6 deletions

diff --git a/tools/perf/util/mmap.c b/tools/perf/util/mmap.c
index 2ee4faacca21..3b664fa673a6 100644
--- a/tools/perf/util/mmap.c
+++ b/tools/perf/util/mmap.c
@@ -219,6 +219,8 @@ static void perf_mmap__aio_munmap(struct mmap *map __maybe_unused)
 
 void mmap__munmap(struct mmap *map)
 {
+	bitmap_free(map->affinity_mask.bits);
+
 	perf_mmap__aio_munmap(map);
 	if (map->data != NULL) {
 		munmap(map->data, mmap__mmap_len(map));
@@ -227,7 +229,7 @@ void mmap__munmap(struct mmap *map)
 	auxtrace_mmap__munmap(&map->auxtrace_mmap);
 }
 
-static void build_node_mask(int node, cpu_set_t *mask)
+static void build_node_mask(int node, struct mmap_cpu_mask *mask)
 {
 	int c, cpu, nr_cpus;
 	const struct perf_cpu_map *cpu_map = NULL;
@@ -240,17 +242,23 @@ static void build_node_mask(int node, cpu_set_t *mask)
 	for (c = 0; c < nr_cpus; c++) {
 		cpu = cpu_map->map[c]; /* map c index to online cpu index */
 		if (cpu__get_node(cpu) == node)
-			CPU_SET(cpu, mask);
+			set_bit(cpu, mask->bits);
 	}
 }
 
-static void perf_mmap__setup_affinity_mask(struct mmap *map, struct mmap_params *mp)
+static int perf_mmap__setup_affinity_mask(struct mmap *map, struct mmap_params *mp)
 {
-	CPU_ZERO(&map->affinity_mask);
+	map->affinity_mask.nbits = cpu__max_cpu();
+	map->affinity_mask.bits = bitmap_alloc(map->affinity_mask.nbits);
+	if (!map->affinity_mask.bits)
+		return -1;
+
 	if (mp->affinity == PERF_AFFINITY_NODE && cpu__max_node() > 1)
 		build_node_mask(cpu__get_node(map->core.cpu), &map->affinity_mask);
 	else if (mp->affinity == PERF_AFFINITY_CPU)
-		CPU_SET(map->core.cpu, &map->affinity_mask);
+		set_bit(map->core.cpu, map->affinity_mask.bits);
+
+	return 0;
 }
 
 int mmap__mmap(struct mmap *map, struct mmap_params *mp, int fd, int cpu)
@@ -261,7 +269,15 @@ int mmap__mmap(struct mmap *map, struct mmap_params *mp, int fd, int cpu)
 		return -1;
 	}
 
-	perf_mmap__setup_affinity_mask(map, mp);
+	if (mp->affinity != PERF_AFFINITY_SYS &&
+		perf_mmap__setup_affinity_mask(map, mp)) {
+		pr_debug2("failed to alloc mmap affinity mask, error %d\n",
+			  errno);
+		return -1;
+	}
+
+	if (verbose == 2)
+		mmap_cpu_mask__scnprintf(&map->affinity_mask, "mmap");
 
 	map->core.flush = mp->flush;