Commit 8384a260 authored by Alexey Budankov's avatar Alexey Budankov Committed by Arnaldo Carvalho de Melo
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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: default avatarAndi Kleen <ak@linux.intel.com>
Signed-off-by: default avatarAlexey Budankov <alexey.budankov@linux.intel.com>
Acked-by: default avatarJiri 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: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 9c080c02

tools/perf/builtin-record.c

+22 −6
Original line number Diff line number Diff line
@@ -62,6 +62,7 @@ 
#include <linux/string.h>

#include <linux/time64.h>

#include <linux/zalloc.h>

#include <linux/bitmap.h>



struct switch_output {

	bool		 enabled;
@@ -93,7 +94,7 @@ struct record { 
	bool			timestamp_boundary;

	struct switch_output	switch_output;

	unsigned long long	samples;

	cpu_set_t		affinity_mask;

	struct mmap_cpu_mask	affinity_mask;

	unsigned long		output_max_size;	/* = 0: unlimited */

};
@@ -961,10 +962,15 @@ static struct perf_event_header finished_round_event = { 
static void record__adjust_affinity(struct record *rec, struct mmap *map)

{

	if (rec->opts.affinity != PERF_AFFINITY_SYS &&

	    !CPU_EQUAL(&rec->affinity_mask, &map->affinity_mask)) {

		CPU_ZERO(&rec->affinity_mask);

		CPU_OR(&rec->affinity_mask, &rec->affinity_mask, &map->affinity_mask);

		sched_setaffinity(0, sizeof(rec->affinity_mask), &rec->affinity_mask);

	    !bitmap_equal(rec->affinity_mask.bits, map->affinity_mask.bits,

			  rec->affinity_mask.nbits)) {

		bitmap_zero(rec->affinity_mask.bits, rec->affinity_mask.nbits);

		bitmap_or(rec->affinity_mask.bits, rec->affinity_mask.bits,

			  map->affinity_mask.bits, rec->affinity_mask.nbits);

		sched_setaffinity(0, MMAP_CPU_MASK_BYTES(&rec->affinity_mask),

				  (cpu_set_t *)rec->affinity_mask.bits);

		if (verbose == 2)

			mmap_cpu_mask__scnprintf(&rec->affinity_mask, "thread");

	}

}
@@ -2433,7 +2439,6 @@ int cmd_record(int argc, const char **argv) 
# undef REASON

#endif



	CPU_ZERO(&rec->affinity_mask);

	rec->opts.affinity = PERF_AFFINITY_SYS;



	rec->evlist = evlist__new();
@@ -2499,6 +2504,16 @@ int cmd_record(int argc, const char **argv) 


	symbol__init(NULL);



	if (rec->opts.affinity != PERF_AFFINITY_SYS) {

		rec->affinity_mask.nbits = cpu__max_cpu();

		rec->affinity_mask.bits = bitmap_alloc(rec->affinity_mask.nbits);

		if (!rec->affinity_mask.bits) {

			pr_err("Failed to allocate thread mask for %zd cpus\n", rec->affinity_mask.nbits);

			return -ENOMEM;

		}

		pr_debug2("thread mask[%zd]: empty\n", rec->affinity_mask.nbits);

	}



	err = record__auxtrace_init(rec);

	if (err)

		goto out;
@@ -2613,6 +2628,7 @@ int cmd_record(int argc, const char **argv) 


	err = __cmd_record(&record, argc, argv);

out:

	bitmap_free(rec->affinity_mask.bits);

	evlist__delete(rec->evlist);

	symbol__exit();

	auxtrace_record__free(rec->itr);

tools/perf/util/mmap.c

+22 −6
Original line number Diff line number Diff line
@@ -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;

tools/perf/util/mmap.h

+1 −1
Original line number Diff line number Diff line
@@ -40,7 +40,7 @@ struct mmap { 
		int		 nr_cblocks;

	} aio;

#endif

	cpu_set_t	affinity_mask;

	struct mmap_cpu_mask	affinity_mask;

	void		*data;

	int		comp_level;

};

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