* Re: [PATCH v2 2/2] perf bench: Add -t/--threads option to perf bench mem mmap
2026-02-19 0:44 ` [PATCH v2 2/2] perf bench: Add -t/--threads option to perf bench mem mmap Namhyung Kim
@ 2026-02-19 10:43 ` James Clark
2026-02-26 7:02 ` Ankur Arora
2026-02-27 21:42 ` Namhyung Kim
2 siblings, 0 replies; 11+ messages in thread
From: James Clark @ 2026-02-19 10:43 UTC (permalink / raw)
To: Namhyung Kim, Arnaldo Carvalho de Melo, Ian Rogers
Cc: Jiri Olsa, Adrian Hunter, Peter Zijlstra, Ingo Molnar, LKML,
linux-perf-users, Ankur Arora
On 19/02/2026 12:44 am, Namhyung Kim wrote:
> So that it can measure overhead of mmap_lock and/or per-VMA lock
> contention.
>
> $ perf bench mem mmap -f demand -l 1000 -t 1
> # Running 'mem/mmap' benchmark:
> # function 'demand' (Demand loaded mmap())
> # Copying 1MB bytes ...
>
> 2.786858 GB/sec
>
> $ perf bench mem mmap -f demand -l 1000 -t 2
> # Running 'mem/mmap' benchmark:
> # function 'demand' (Demand loaded mmap())
> # Copying 1MB bytes ...
>
> 1.624468 GB/sec/thread ( +- 0.30% )
>
> $ perf bench mem mmap -f demand -l 1000 -t 3
> # Running 'mem/mmap' benchmark:
> # function 'demand' (Demand loaded mmap())
> # Copying 1MB bytes ...
>
> 1.493068 GB/sec/thread ( +- 0.15% )
>
> $ perf bench mem mmap -f demand -l 1000 -t 4
> # Running 'mem/mmap' benchmark:
> # function 'demand' (Demand loaded mmap())
> # Copying 1MB bytes ...
>
> 1.006087 GB/sec/thread ( +- 0.41% )
>
> Cc: Ankur Arora <ankur.a.arora@oracle.com>
> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
> ---
> v2)
> * correct timeval2double calculation
> * add "/thread" notation when -t > 1 (James)
> * add stddev when -t > 1 (Ankur)
>
> tools/perf/Documentation/perf-bench.txt | 4 +
> tools/perf/bench/mem-functions.c | 109 +++++++++++++++++++-----
> 2 files changed, 92 insertions(+), 21 deletions(-)
>
Reviewed-by: James Clark <james.clark@linaro.org>
> diff --git a/tools/perf/Documentation/perf-bench.txt b/tools/perf/Documentation/perf-bench.txt
> index 1160224cb718392d..c5913cf59c988421 100644
> --- a/tools/perf/Documentation/perf-bench.txt
> +++ b/tools/perf/Documentation/perf-bench.txt
> @@ -274,6 +274,10 @@ Repeat mmap() invocation this number of times.
> --cycles::
> Use perf's cpu-cycles event instead of gettimeofday syscall.
>
> +-t::
> +--threads=<NUM>::
> +Create multiple threads to call mmap/munmap concurrently.
> +
> SUITES FOR 'numa'
> ~~~~~~~~~~~~~~~~~
> *mem*::
> diff --git a/tools/perf/bench/mem-functions.c b/tools/perf/bench/mem-functions.c
> index 676c8d18f4c2e259..8e04ae69f8a85c5e 100644
> --- a/tools/perf/bench/mem-functions.c
> +++ b/tools/perf/bench/mem-functions.c
> @@ -7,13 +7,14 @@
> * Written by Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
> */
>
> -#include "debug.h"
> +#include "bench.h"
> #include "../perf-sys.h"
> #include <subcmd/parse-options.h>
> -#include "../util/header.h"
> -#include "../util/cloexec.h"
> -#include "../util/string2.h"
> -#include "bench.h"
> +#include "util/cloexec.h"
> +#include "util/debug.h"
> +#include "util/header.h"
> +#include "util/stat.h"
> +#include "util/string2.h"
> #include "mem-memcpy-arch.h"
> #include "mem-memset-arch.h"
>
> @@ -26,6 +27,7 @@
> #include <errno.h>
> #include <linux/time64.h>
> #include <linux/log2.h>
> +#include <pthread.h>
>
> #define K 1024
>
> @@ -41,6 +43,7 @@ static unsigned int nr_loops = 1;
> static bool use_cycles;
> static int cycles_fd;
> static unsigned int seed;
> +static unsigned int nr_threads = 1;
>
> static const struct option bench_common_options[] = {
> OPT_STRING('s', "size", &size_str, "1MB",
> @@ -121,6 +124,8 @@ static struct perf_event_attr cycle_attr = {
> .config = PERF_COUNT_HW_CPU_CYCLES
> };
>
> +static struct stats stats;
> +
> static int init_cycles(void)
> {
> cycles_fd = sys_perf_event_open(&cycle_attr, getpid(), -1, -1, perf_event_open_cloexec_flag());
> @@ -174,18 +179,18 @@ static void clock_accum(union bench_clock *a, union bench_clock *b)
>
> static double timeval2double(struct timeval *ts)
> {
> - return (double)ts->tv_sec + (double)ts->tv_usec / (double)USEC_PER_SEC;
> + return ((double)ts->tv_sec + (double)ts->tv_usec / (double)USEC_PER_SEC) / nr_threads;
> }
>
> #define print_bps(x) do { \
> if (x < K) \
> - printf(" %14lf bytes/sec\n", x); \
> + printf(" %14lf bytes/sec", x); \
> else if (x < K * K) \
> - printf(" %14lfd KB/sec\n", x / K); \
> + printf(" %14lfd KB/sec", x / K); \
> else if (x < K * K * K) \
> - printf(" %14lf MB/sec\n", x / K / K); \
> + printf(" %14lf MB/sec", x / K / K); \
> else \
> - printf(" %14lf GB/sec\n", x / K / K / K); \
> + printf(" %14lf GB/sec", x / K / K / K); \
> } while (0)
>
> static void __bench_mem_function(struct bench_mem_info *info, struct bench_params *p,
> @@ -197,6 +202,7 @@ static void __bench_mem_function(struct bench_mem_info *info, struct bench_param
> void *src = NULL, *dst = NULL;
>
> memset(&rt, 0, sizeof(rt));
> + init_stats(&stats);
> printf("# function '%s' (%s)\n", r->name, r->desc);
>
> if (r->fn.init && r->fn.init(info, p, &src, &dst))
> @@ -211,11 +217,16 @@ static void __bench_mem_function(struct bench_mem_info *info, struct bench_param
> switch (bench_format) {
> case BENCH_FORMAT_DEFAULT:
> if (use_cycles) {
> - printf(" %14lf cycles/byte\n", (double)rt.cycles/(double)p->size_total);
> + printf(" %14lf cycles/byte", (double)rt.cycles/(double)p->size_total);
> } else {
> result_bps = (double)p->size_total/timeval2double(&rt.tv);
> print_bps(result_bps);
> }
> + if (nr_threads > 1) {
> + printf("/thread\t( +- %6.2f%% )",
> + rel_stddev_stats(stddev_stats(&stats), avg_stats(&stats)));
> + }
> + printf("\n");
> break;
>
> case BENCH_FORMAT_SIMPLE:
> @@ -495,16 +506,27 @@ static void mmap_page_touch(void *dst, size_t size, unsigned int page_shift, boo
> }
> }
>
> -static int do_mmap(const struct function *r, struct bench_params *p,
> - void *src __maybe_unused, void *dst __maybe_unused,
> - union bench_clock *accum)
> +struct mmap_data {
> + pthread_t id;
> + const struct function *func;
> + struct bench_params *params;
> + union bench_clock result;
> + unsigned int seed;
> + int error;
> +};
> +
> +static void *do_mmap_thread(void *arg)
> {
> + struct mmap_data *data = arg;
> + const struct function *r = data->func;
> + struct bench_params *p = data->params;
> union bench_clock start, end, diff;
> mmap_op_t fn = r->fn.mmap_op;
> bool populate = strcmp(r->name, "populate") == 0;
> + void *dst;
>
> - if (p->seed)
> - srand(p->seed);
> + if (data->seed)
> + srand(data->seed);
>
> for (unsigned int i = 0; i < p->nr_loops; i++) {
> clock_get(&start);
> @@ -515,16 +537,59 @@ static int do_mmap(const struct function *r, struct bench_params *p,
> fn(dst, p->size, p->page_shift, p->seed);
> clock_get(&end);
> diff = clock_diff(&start, &end);
> - clock_accum(accum, &diff);
> + clock_accum(&data->result, &diff);
>
> bench_munmap(dst, p->size);
> }
>
> - return 0;
> + return data;
> out:
> - printf("# Memory allocation failed - maybe size (%s) %s?\n", size_str,
> - p->page_shift != PAGE_SHIFT_4KB ? "has insufficient hugepages" : "is too large");
> - return -1;
> + data->error = -ENOMEM;
> + return NULL;
> +}
> +
> +static int do_mmap(const struct function *r, struct bench_params *p,
> + void *src __maybe_unused, void *dst __maybe_unused,
> + union bench_clock *accum)
> +{
> + struct mmap_data *data;
> + int error = 0;
> +
> + data = calloc(nr_threads, sizeof(*data));
> + if (!data) {
> + printf("# Failed to allocate thread resources\n");
> + return -1;
> + }
> +
> + for (unsigned int i = 0; i < nr_threads; i++) {
> + data[i].func = r;
> + data[i].params = p;
> + if (p->seed)
> + data[i].seed = p->seed + i;
> +
> + if (pthread_create(&data[i].id, NULL, do_mmap_thread, &data[i]) < 0)
> + data[i].error = -errno;
> + }
> +
> + for (unsigned int i = 0; i < nr_threads; i++) {
> + union bench_clock *t = &data[i].result;
> +
> + pthread_join(data[i].id, NULL);
> +
> + clock_accum(accum, t);
> + if (use_cycles)
> + update_stats(&stats, t->cycles);
> + else
> + update_stats(&stats, t->tv.tv_sec * 1e6 + t->tv.tv_usec);
> + error |= data[i].error;
> + }
> + free(data);
> +
> + if (error) {
> + printf("# Memory allocation failed - maybe size (%s) %s?\n", size_str,
> + p->page_shift != PAGE_SHIFT_4KB ? "has insufficient hugepages" : "is too large");
> + }
> + return error ? -1 : 0;
> }
>
> static const char * const bench_mem_mmap_usage[] = {
> @@ -549,6 +614,8 @@ int bench_mem_mmap(int argc, const char **argv)
> static const struct option bench_mmap_options[] = {
> OPT_UINTEGER('r', "randomize", &seed,
> "Seed to randomize page access offset."),
> + OPT_UINTEGER('t', "threads", &nr_threads,
> + "Number of threads to run concurrently (default: 1)."),
> OPT_PARENT(bench_common_options),
> OPT_END()
> };
^ permalink raw reply [flat|nested] 11+ messages in thread* Re: [PATCH v2 2/2] perf bench: Add -t/--threads option to perf bench mem mmap
2026-02-19 0:44 ` [PATCH v2 2/2] perf bench: Add -t/--threads option to perf bench mem mmap Namhyung Kim
2026-02-19 10:43 ` James Clark
@ 2026-02-26 7:02 ` Ankur Arora
2026-02-27 21:42 ` Namhyung Kim
2 siblings, 0 replies; 11+ messages in thread
From: Ankur Arora @ 2026-02-26 7:02 UTC (permalink / raw)
To: Namhyung Kim
Cc: Arnaldo Carvalho de Melo, Ian Rogers, James Clark, Jiri Olsa,
Adrian Hunter, Peter Zijlstra, Ingo Molnar, LKML,
linux-perf-users, Ankur Arora
Namhyung Kim <namhyung@kernel.org> writes:
> So that it can measure overhead of mmap_lock and/or per-VMA lock
> contention.
>
> $ perf bench mem mmap -f demand -l 1000 -t 1
> # Running 'mem/mmap' benchmark:
> # function 'demand' (Demand loaded mmap())
> # Copying 1MB bytes ...
>
> 2.786858 GB/sec
>
> $ perf bench mem mmap -f demand -l 1000 -t 2
> # Running 'mem/mmap' benchmark:
> # function 'demand' (Demand loaded mmap())
> # Copying 1MB bytes ...
>
> 1.624468 GB/sec/thread ( +- 0.30% )
>
> $ perf bench mem mmap -f demand -l 1000 -t 3
> # Running 'mem/mmap' benchmark:
> # function 'demand' (Demand loaded mmap())
> # Copying 1MB bytes ...
>
> 1.493068 GB/sec/thread ( +- 0.15% )
>
> $ perf bench mem mmap -f demand -l 1000 -t 4
> # Running 'mem/mmap' benchmark:
> # function 'demand' (Demand loaded mmap())
> # Copying 1MB bytes ...
>
> 1.006087 GB/sec/thread ( +- 0.41% )
>
> Cc: Ankur Arora <ankur.a.arora@oracle.com>
> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Reviewed-by: Ankur Arora <ankur.a.arora@oracle.com>
> ---
> v2)
> * correct timeval2double calculation
> * add "/thread" notation when -t > 1 (James)
> * add stddev when -t > 1 (Ankur)
>
> tools/perf/Documentation/perf-bench.txt | 4 +
> tools/perf/bench/mem-functions.c | 109 +++++++++++++++++++-----
> 2 files changed, 92 insertions(+), 21 deletions(-)
>
> diff --git a/tools/perf/Documentation/perf-bench.txt b/tools/perf/Documentation/perf-bench.txt
> index 1160224cb718392d..c5913cf59c988421 100644
> --- a/tools/perf/Documentation/perf-bench.txt
> +++ b/tools/perf/Documentation/perf-bench.txt
> @@ -274,6 +274,10 @@ Repeat mmap() invocation this number of times.
> --cycles::
> Use perf's cpu-cycles event instead of gettimeofday syscall.
>
> +-t::
> +--threads=<NUM>::
> +Create multiple threads to call mmap/munmap concurrently.
> +
> SUITES FOR 'numa'
> ~~~~~~~~~~~~~~~~~
> *mem*::
> diff --git a/tools/perf/bench/mem-functions.c b/tools/perf/bench/mem-functions.c
> index 676c8d18f4c2e259..8e04ae69f8a85c5e 100644
> --- a/tools/perf/bench/mem-functions.c
> +++ b/tools/perf/bench/mem-functions.c
> @@ -7,13 +7,14 @@
> * Written by Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
> */
>
> -#include "debug.h"
> +#include "bench.h"
> #include "../perf-sys.h"
> #include <subcmd/parse-options.h>
> -#include "../util/header.h"
> -#include "../util/cloexec.h"
> -#include "../util/string2.h"
> -#include "bench.h"
> +#include "util/cloexec.h"
> +#include "util/debug.h"
> +#include "util/header.h"
> +#include "util/stat.h"
> +#include "util/string2.h"
> #include "mem-memcpy-arch.h"
> #include "mem-memset-arch.h"
>
> @@ -26,6 +27,7 @@
> #include <errno.h>
> #include <linux/time64.h>
> #include <linux/log2.h>
> +#include <pthread.h>
>
> #define K 1024
>
> @@ -41,6 +43,7 @@ static unsigned int nr_loops = 1;
> static bool use_cycles;
> static int cycles_fd;
> static unsigned int seed;
> +static unsigned int nr_threads = 1;
>
> static const struct option bench_common_options[] = {
> OPT_STRING('s', "size", &size_str, "1MB",
> @@ -121,6 +124,8 @@ static struct perf_event_attr cycle_attr = {
> .config = PERF_COUNT_HW_CPU_CYCLES
> };
>
> +static struct stats stats;
> +
> static int init_cycles(void)
> {
> cycles_fd = sys_perf_event_open(&cycle_attr, getpid(), -1, -1, perf_event_open_cloexec_flag());
> @@ -174,18 +179,18 @@ static void clock_accum(union bench_clock *a, union bench_clock *b)
>
> static double timeval2double(struct timeval *ts)
> {
> - return (double)ts->tv_sec + (double)ts->tv_usec / (double)USEC_PER_SEC;
> + return ((double)ts->tv_sec + (double)ts->tv_usec / (double)USEC_PER_SEC) / nr_threads;
> }
>
> #define print_bps(x) do { \
> if (x < K) \
> - printf(" %14lf bytes/sec\n", x); \
> + printf(" %14lf bytes/sec", x); \
> else if (x < K * K) \
> - printf(" %14lfd KB/sec\n", x / K); \
> + printf(" %14lfd KB/sec", x / K); \
> else if (x < K * K * K) \
> - printf(" %14lf MB/sec\n", x / K / K); \
> + printf(" %14lf MB/sec", x / K / K); \
> else \
> - printf(" %14lf GB/sec\n", x / K / K / K); \
> + printf(" %14lf GB/sec", x / K / K / K); \
> } while (0)
>
> static void __bench_mem_function(struct bench_mem_info *info, struct bench_params *p,
> @@ -197,6 +202,7 @@ static void __bench_mem_function(struct bench_mem_info *info, struct bench_param
> void *src = NULL, *dst = NULL;
>
> memset(&rt, 0, sizeof(rt));
> + init_stats(&stats);
> printf("# function '%s' (%s)\n", r->name, r->desc);
>
> if (r->fn.init && r->fn.init(info, p, &src, &dst))
> @@ -211,11 +217,16 @@ static void __bench_mem_function(struct bench_mem_info *info, struct bench_param
> switch (bench_format) {
> case BENCH_FORMAT_DEFAULT:
> if (use_cycles) {
> - printf(" %14lf cycles/byte\n", (double)rt.cycles/(double)p->size_total);
> + printf(" %14lf cycles/byte", (double)rt.cycles/(double)p->size_total);
> } else {
> result_bps = (double)p->size_total/timeval2double(&rt.tv);
> print_bps(result_bps);
> }
> + if (nr_threads > 1) {
> + printf("/thread\t( +- %6.2f%% )",
> + rel_stddev_stats(stddev_stats(&stats), avg_stats(&stats)));
> + }
> + printf("\n");
> break;
>
> case BENCH_FORMAT_SIMPLE:
> @@ -495,16 +506,27 @@ static void mmap_page_touch(void *dst, size_t size, unsigned int page_shift, boo
> }
> }
>
> -static int do_mmap(const struct function *r, struct bench_params *p,
> - void *src __maybe_unused, void *dst __maybe_unused,
> - union bench_clock *accum)
> +struct mmap_data {
> + pthread_t id;
> + const struct function *func;
> + struct bench_params *params;
> + union bench_clock result;
> + unsigned int seed;
> + int error;
> +};
> +
> +static void *do_mmap_thread(void *arg)
> {
> + struct mmap_data *data = arg;
> + const struct function *r = data->func;
> + struct bench_params *p = data->params;
> union bench_clock start, end, diff;
> mmap_op_t fn = r->fn.mmap_op;
> bool populate = strcmp(r->name, "populate") == 0;
> + void *dst;
>
> - if (p->seed)
> - srand(p->seed);
> + if (data->seed)
> + srand(data->seed);
>
> for (unsigned int i = 0; i < p->nr_loops; i++) {
> clock_get(&start);
> @@ -515,16 +537,59 @@ static int do_mmap(const struct function *r, struct bench_params *p,
> fn(dst, p->size, p->page_shift, p->seed);
> clock_get(&end);
> diff = clock_diff(&start, &end);
> - clock_accum(accum, &diff);
> + clock_accum(&data->result, &diff);
>
> bench_munmap(dst, p->size);
> }
>
> - return 0;
> + return data;
> out:
> - printf("# Memory allocation failed - maybe size (%s) %s?\n", size_str,
> - p->page_shift != PAGE_SHIFT_4KB ? "has insufficient hugepages" : "is too large");
> - return -1;
> + data->error = -ENOMEM;
> + return NULL;
> +}
> +
> +static int do_mmap(const struct function *r, struct bench_params *p,
> + void *src __maybe_unused, void *dst __maybe_unused,
> + union bench_clock *accum)
> +{
> + struct mmap_data *data;
> + int error = 0;
> +
> + data = calloc(nr_threads, sizeof(*data));
> + if (!data) {
> + printf("# Failed to allocate thread resources\n");
> + return -1;
> + }
> +
> + for (unsigned int i = 0; i < nr_threads; i++) {
> + data[i].func = r;
> + data[i].params = p;
> + if (p->seed)
> + data[i].seed = p->seed + i;
> +
> + if (pthread_create(&data[i].id, NULL, do_mmap_thread, &data[i]) < 0)
> + data[i].error = -errno;
> + }
> +
> + for (unsigned int i = 0; i < nr_threads; i++) {
> + union bench_clock *t = &data[i].result;
> +
> + pthread_join(data[i].id, NULL);
> +
> + clock_accum(accum, t);
> + if (use_cycles)
> + update_stats(&stats, t->cycles);
> + else
> + update_stats(&stats, t->tv.tv_sec * 1e6 + t->tv.tv_usec);
> + error |= data[i].error;
> + }
> + free(data);
> +
> + if (error) {
> + printf("# Memory allocation failed - maybe size (%s) %s?\n", size_str,
> + p->page_shift != PAGE_SHIFT_4KB ? "has insufficient hugepages" : "is too large");
> + }
> + return error ? -1 : 0;
> }
>
> static const char * const bench_mem_mmap_usage[] = {
> @@ -549,6 +614,8 @@ int bench_mem_mmap(int argc, const char **argv)
> static const struct option bench_mmap_options[] = {
> OPT_UINTEGER('r', "randomize", &seed,
> "Seed to randomize page access offset."),
> + OPT_UINTEGER('t', "threads", &nr_threads,
> + "Number of threads to run concurrently (default: 1)."),
> OPT_PARENT(bench_common_options),
> OPT_END()
> };
--
ankur
^ permalink raw reply [flat|nested] 11+ messages in thread* Re: [PATCH v2 2/2] perf bench: Add -t/--threads option to perf bench mem mmap
2026-02-19 0:44 ` [PATCH v2 2/2] perf bench: Add -t/--threads option to perf bench mem mmap Namhyung Kim
2026-02-19 10:43 ` James Clark
2026-02-26 7:02 ` Ankur Arora
@ 2026-02-27 21:42 ` Namhyung Kim
2 siblings, 0 replies; 11+ messages in thread
From: Namhyung Kim @ 2026-02-27 21:42 UTC (permalink / raw)
To: Arnaldo Carvalho de Melo, Ian Rogers, James Clark
Cc: Jiri Olsa, Adrian Hunter, Peter Zijlstra, Ingo Molnar, LKML,
linux-perf-users, Ankur Arora
On Wed, Feb 18, 2026 at 04:44:17PM -0800, Namhyung Kim wrote:
> So that it can measure overhead of mmap_lock and/or per-VMA lock
> contention.
>
> $ perf bench mem mmap -f demand -l 1000 -t 1
> # Running 'mem/mmap' benchmark:
> # function 'demand' (Demand loaded mmap())
> # Copying 1MB bytes ...
>
> 2.786858 GB/sec
>
> $ perf bench mem mmap -f demand -l 1000 -t 2
> # Running 'mem/mmap' benchmark:
> # function 'demand' (Demand loaded mmap())
> # Copying 1MB bytes ...
>
> 1.624468 GB/sec/thread ( +- 0.30% )
>
> $ perf bench mem mmap -f demand -l 1000 -t 3
> # Running 'mem/mmap' benchmark:
> # function 'demand' (Demand loaded mmap())
> # Copying 1MB bytes ...
>
> 1.493068 GB/sec/thread ( +- 0.15% )
>
> $ perf bench mem mmap -f demand -l 1000 -t 4
> # Running 'mem/mmap' benchmark:
> # function 'demand' (Demand loaded mmap())
> # Copying 1MB bytes ...
>
> 1.006087 GB/sec/thread ( +- 0.41% )
>
> Cc: Ankur Arora <ankur.a.arora@oracle.com>
> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Applied only this patch to perf-tools-next.
Thanks,
Namhyung
> ---
> v2)
> * correct timeval2double calculation
> * add "/thread" notation when -t > 1 (James)
> * add stddev when -t > 1 (Ankur)
>
> tools/perf/Documentation/perf-bench.txt | 4 +
> tools/perf/bench/mem-functions.c | 109 +++++++++++++++++++-----
> 2 files changed, 92 insertions(+), 21 deletions(-)
>
> diff --git a/tools/perf/Documentation/perf-bench.txt b/tools/perf/Documentation/perf-bench.txt
> index 1160224cb718392d..c5913cf59c988421 100644
> --- a/tools/perf/Documentation/perf-bench.txt
> +++ b/tools/perf/Documentation/perf-bench.txt
> @@ -274,6 +274,10 @@ Repeat mmap() invocation this number of times.
> --cycles::
> Use perf's cpu-cycles event instead of gettimeofday syscall.
>
> +-t::
> +--threads=<NUM>::
> +Create multiple threads to call mmap/munmap concurrently.
> +
> SUITES FOR 'numa'
> ~~~~~~~~~~~~~~~~~
> *mem*::
> diff --git a/tools/perf/bench/mem-functions.c b/tools/perf/bench/mem-functions.c
> index 676c8d18f4c2e259..8e04ae69f8a85c5e 100644
> --- a/tools/perf/bench/mem-functions.c
> +++ b/tools/perf/bench/mem-functions.c
> @@ -7,13 +7,14 @@
> * Written by Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
> */
>
> -#include "debug.h"
> +#include "bench.h"
> #include "../perf-sys.h"
> #include <subcmd/parse-options.h>
> -#include "../util/header.h"
> -#include "../util/cloexec.h"
> -#include "../util/string2.h"
> -#include "bench.h"
> +#include "util/cloexec.h"
> +#include "util/debug.h"
> +#include "util/header.h"
> +#include "util/stat.h"
> +#include "util/string2.h"
> #include "mem-memcpy-arch.h"
> #include "mem-memset-arch.h"
>
> @@ -26,6 +27,7 @@
> #include <errno.h>
> #include <linux/time64.h>
> #include <linux/log2.h>
> +#include <pthread.h>
>
> #define K 1024
>
> @@ -41,6 +43,7 @@ static unsigned int nr_loops = 1;
> static bool use_cycles;
> static int cycles_fd;
> static unsigned int seed;
> +static unsigned int nr_threads = 1;
>
> static const struct option bench_common_options[] = {
> OPT_STRING('s', "size", &size_str, "1MB",
> @@ -121,6 +124,8 @@ static struct perf_event_attr cycle_attr = {
> .config = PERF_COUNT_HW_CPU_CYCLES
> };
>
> +static struct stats stats;
> +
> static int init_cycles(void)
> {
> cycles_fd = sys_perf_event_open(&cycle_attr, getpid(), -1, -1, perf_event_open_cloexec_flag());
> @@ -174,18 +179,18 @@ static void clock_accum(union bench_clock *a, union bench_clock *b)
>
> static double timeval2double(struct timeval *ts)
> {
> - return (double)ts->tv_sec + (double)ts->tv_usec / (double)USEC_PER_SEC;
> + return ((double)ts->tv_sec + (double)ts->tv_usec / (double)USEC_PER_SEC) / nr_threads;
> }
>
> #define print_bps(x) do { \
> if (x < K) \
> - printf(" %14lf bytes/sec\n", x); \
> + printf(" %14lf bytes/sec", x); \
> else if (x < K * K) \
> - printf(" %14lfd KB/sec\n", x / K); \
> + printf(" %14lfd KB/sec", x / K); \
> else if (x < K * K * K) \
> - printf(" %14lf MB/sec\n", x / K / K); \
> + printf(" %14lf MB/sec", x / K / K); \
> else \
> - printf(" %14lf GB/sec\n", x / K / K / K); \
> + printf(" %14lf GB/sec", x / K / K / K); \
> } while (0)
>
> static void __bench_mem_function(struct bench_mem_info *info, struct bench_params *p,
> @@ -197,6 +202,7 @@ static void __bench_mem_function(struct bench_mem_info *info, struct bench_param
> void *src = NULL, *dst = NULL;
>
> memset(&rt, 0, sizeof(rt));
> + init_stats(&stats);
> printf("# function '%s' (%s)\n", r->name, r->desc);
>
> if (r->fn.init && r->fn.init(info, p, &src, &dst))
> @@ -211,11 +217,16 @@ static void __bench_mem_function(struct bench_mem_info *info, struct bench_param
> switch (bench_format) {
> case BENCH_FORMAT_DEFAULT:
> if (use_cycles) {
> - printf(" %14lf cycles/byte\n", (double)rt.cycles/(double)p->size_total);
> + printf(" %14lf cycles/byte", (double)rt.cycles/(double)p->size_total);
> } else {
> result_bps = (double)p->size_total/timeval2double(&rt.tv);
> print_bps(result_bps);
> }
> + if (nr_threads > 1) {
> + printf("/thread\t( +- %6.2f%% )",
> + rel_stddev_stats(stddev_stats(&stats), avg_stats(&stats)));
> + }
> + printf("\n");
> break;
>
> case BENCH_FORMAT_SIMPLE:
> @@ -495,16 +506,27 @@ static void mmap_page_touch(void *dst, size_t size, unsigned int page_shift, boo
> }
> }
>
> -static int do_mmap(const struct function *r, struct bench_params *p,
> - void *src __maybe_unused, void *dst __maybe_unused,
> - union bench_clock *accum)
> +struct mmap_data {
> + pthread_t id;
> + const struct function *func;
> + struct bench_params *params;
> + union bench_clock result;
> + unsigned int seed;
> + int error;
> +};
> +
> +static void *do_mmap_thread(void *arg)
> {
> + struct mmap_data *data = arg;
> + const struct function *r = data->func;
> + struct bench_params *p = data->params;
> union bench_clock start, end, diff;
> mmap_op_t fn = r->fn.mmap_op;
> bool populate = strcmp(r->name, "populate") == 0;
> + void *dst;
>
> - if (p->seed)
> - srand(p->seed);
> + if (data->seed)
> + srand(data->seed);
>
> for (unsigned int i = 0; i < p->nr_loops; i++) {
> clock_get(&start);
> @@ -515,16 +537,59 @@ static int do_mmap(const struct function *r, struct bench_params *p,
> fn(dst, p->size, p->page_shift, p->seed);
> clock_get(&end);
> diff = clock_diff(&start, &end);
> - clock_accum(accum, &diff);
> + clock_accum(&data->result, &diff);
>
> bench_munmap(dst, p->size);
> }
>
> - return 0;
> + return data;
> out:
> - printf("# Memory allocation failed - maybe size (%s) %s?\n", size_str,
> - p->page_shift != PAGE_SHIFT_4KB ? "has insufficient hugepages" : "is too large");
> - return -1;
> + data->error = -ENOMEM;
> + return NULL;
> +}
> +
> +static int do_mmap(const struct function *r, struct bench_params *p,
> + void *src __maybe_unused, void *dst __maybe_unused,
> + union bench_clock *accum)
> +{
> + struct mmap_data *data;
> + int error = 0;
> +
> + data = calloc(nr_threads, sizeof(*data));
> + if (!data) {
> + printf("# Failed to allocate thread resources\n");
> + return -1;
> + }
> +
> + for (unsigned int i = 0; i < nr_threads; i++) {
> + data[i].func = r;
> + data[i].params = p;
> + if (p->seed)
> + data[i].seed = p->seed + i;
> +
> + if (pthread_create(&data[i].id, NULL, do_mmap_thread, &data[i]) < 0)
> + data[i].error = -errno;
> + }
> +
> + for (unsigned int i = 0; i < nr_threads; i++) {
> + union bench_clock *t = &data[i].result;
> +
> + pthread_join(data[i].id, NULL);
> +
> + clock_accum(accum, t);
> + if (use_cycles)
> + update_stats(&stats, t->cycles);
> + else
> + update_stats(&stats, t->tv.tv_sec * 1e6 + t->tv.tv_usec);
> + error |= data[i].error;
> + }
> + free(data);
> +
> + if (error) {
> + printf("# Memory allocation failed - maybe size (%s) %s?\n", size_str,
> + p->page_shift != PAGE_SHIFT_4KB ? "has insufficient hugepages" : "is too large");
> + }
> + return error ? -1 : 0;
> }
>
> static const char * const bench_mem_mmap_usage[] = {
> @@ -549,6 +614,8 @@ int bench_mem_mmap(int argc, const char **argv)
> static const struct option bench_mmap_options[] = {
> OPT_UINTEGER('r', "randomize", &seed,
> "Seed to randomize page access offset."),
> + OPT_UINTEGER('t', "threads", &nr_threads,
> + "Number of threads to run concurrently (default: 1)."),
> OPT_PARENT(bench_common_options),
> OPT_END()
> };
> --
> 2.53.0.335.g19a08e0c02-goog
>
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