linux-stable/tools/perf/builtin-bench.c
Dmitry Vyukov 68a6772f11 perf bench: Add breakpoint benchmarks
Add 2 benchmarks:

1. Performance of thread creation/exiting in presence of breakpoints.
2. Performance of breakpoint modification in presence of threads.

The benchmarks capture use cases that we are interested in:
using inheritable breakpoints in large highly-threaded applications.

The benchmarks show significant slowdown imposed by breakpoints
(even when they don't fire).

Testing on Intel 8173M with 112 HW threads show:

  perf bench --repeat=56 breakpoint thread --breakpoints=0 --parallelism=56 --threads=20
        78.675000 usecs/op
  perf bench --repeat=56 breakpoint thread --breakpoints=4 --parallelism=56 --threads=20
     12967.135714 usecs/op

That's 165x slowdown due to presence of the breakpoints.

  perf bench --repeat=20000 breakpoint enable --passive=0 --active=0
         1.433250 usecs/op
  perf bench --repeat=20000 breakpoint enable --passive=224 --active=0
       585.318400 usecs/op
  perf bench --repeat=20000 breakpoint enable --passive=0 --active=111
       635.953000 usecs/op

That's 408x and 444x slowdown due to presence of threads.

Profiles show some overhead in toggle_bp_slot,
but also very high contention:

    90.83%  breakpoint-thre  [kernel.kallsyms]  [k] osq_lock
     4.69%  breakpoint-thre  [kernel.kallsyms]  [k] mutex_spin_on_owner
     2.06%  breakpoint-thre  [kernel.kallsyms]  [k] __reserve_bp_slot
     2.04%  breakpoint-thre  [kernel.kallsyms]  [k] toggle_bp_slot

    79.01%  breakpoint-enab  [kernel.kallsyms]  [k] smp_call_function_single
     9.94%  breakpoint-enab  [kernel.kallsyms]  [k] llist_add_batch
     5.70%  breakpoint-enab  [kernel.kallsyms]  [k] _raw_spin_lock_irq
     1.84%  breakpoint-enab  [kernel.kallsyms]  [k] event_function_call
     1.12%  breakpoint-enab  [kernel.kallsyms]  [k] send_call_function_single_ipi
     0.37%  breakpoint-enab  [kernel.kallsyms]  [k] generic_exec_single
     0.24%  breakpoint-enab  [kernel.kallsyms]  [k] __perf_event_disable
     0.20%  breakpoint-enab  [kernel.kallsyms]  [k] _perf_event_enable
     0.18%  breakpoint-enab  [kernel.kallsyms]  [k] toggle_bp_slot

Committer notes:

Fixup struct init for older compilers:

   3    32.90 alpine:3.5                    : FAIL clang version 3.8.1 (tags/RELEASE_381/final)
    bench/breakpoint.c:49:34: error: missing field 'size' initializer [-Werror,-Wmissing-field-initializers]
            struct perf_event_attr attr = {0};
                                            ^
    1 error generated.
   7    37.31 alpine:3.9                    : FAIL gcc version 8.3.0 (Alpine 8.3.0)
    bench/breakpoint.c:49:34: error: missing field 'size' initializer [-Werror,-Wmissing-field-initializers]
            struct perf_event_attr attr = {0};
                                            ^
    1 error generated.

Signed-off-by: Dmitriy Vyukov <dvyukov@google.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220505155745.1690906-1-dvyukov@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2022-05-13 11:00:38 -03:00

332 lines
8.6 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* builtin-bench.c
*
* General benchmarking collections provided by perf
*
* Copyright (C) 2009, Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
*/
/*
* Available benchmark collection list:
*
* sched ... scheduler and IPC performance
* syscall ... System call performance
* mem ... memory access performance
* numa ... NUMA scheduling and MM performance
* futex ... Futex performance
* epoll ... Event poll performance
*/
#include <subcmd/parse-options.h>
#include "builtin.h"
#include "bench/bench.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/prctl.h>
#include <linux/zalloc.h>
typedef int (*bench_fn_t)(int argc, const char **argv);
struct bench {
const char *name;
const char *summary;
bench_fn_t fn;
};
#ifdef HAVE_LIBNUMA_SUPPORT
static struct bench numa_benchmarks[] = {
{ "mem", "Benchmark for NUMA workloads", bench_numa },
{ "all", "Run all NUMA benchmarks", NULL },
{ NULL, NULL, NULL }
};
#endif
static struct bench sched_benchmarks[] = {
{ "messaging", "Benchmark for scheduling and IPC", bench_sched_messaging },
{ "pipe", "Benchmark for pipe() between two processes", bench_sched_pipe },
{ "all", "Run all scheduler benchmarks", NULL },
{ NULL, NULL, NULL }
};
static struct bench syscall_benchmarks[] = {
{ "basic", "Benchmark for basic getppid(2) calls", bench_syscall_basic },
{ "all", "Run all syscall benchmarks", NULL },
{ NULL, NULL, NULL },
};
static struct bench mem_benchmarks[] = {
{ "memcpy", "Benchmark for memcpy() functions", bench_mem_memcpy },
{ "memset", "Benchmark for memset() functions", bench_mem_memset },
{ "find_bit", "Benchmark for find_bit() functions", bench_mem_find_bit },
{ "all", "Run all memory access benchmarks", NULL },
{ NULL, NULL, NULL }
};
static struct bench futex_benchmarks[] = {
{ "hash", "Benchmark for futex hash table", bench_futex_hash },
{ "wake", "Benchmark for futex wake calls", bench_futex_wake },
{ "wake-parallel", "Benchmark for parallel futex wake calls", bench_futex_wake_parallel },
{ "requeue", "Benchmark for futex requeue calls", bench_futex_requeue },
/* pi-futexes */
{ "lock-pi", "Benchmark for futex lock_pi calls", bench_futex_lock_pi },
{ "all", "Run all futex benchmarks", NULL },
{ NULL, NULL, NULL }
};
#ifdef HAVE_EVENTFD_SUPPORT
static struct bench epoll_benchmarks[] = {
{ "wait", "Benchmark epoll concurrent epoll_waits", bench_epoll_wait },
{ "ctl", "Benchmark epoll concurrent epoll_ctls", bench_epoll_ctl },
{ "all", "Run all futex benchmarks", NULL },
{ NULL, NULL, NULL }
};
#endif // HAVE_EVENTFD_SUPPORT
static struct bench internals_benchmarks[] = {
{ "synthesize", "Benchmark perf event synthesis", bench_synthesize },
{ "kallsyms-parse", "Benchmark kallsyms parsing", bench_kallsyms_parse },
{ "inject-build-id", "Benchmark build-id injection", bench_inject_build_id },
{ "evlist-open-close", "Benchmark evlist open and close", bench_evlist_open_close },
{ NULL, NULL, NULL }
};
static struct bench breakpoint_benchmarks[] = {
{ "thread", "Benchmark thread start/finish with breakpoints", bench_breakpoint_thread},
{ "enable", "Benchmark breakpoint enable/disable", bench_breakpoint_enable},
{ "all", "Run all breakpoint benchmarks", NULL},
{ NULL, NULL, NULL },
};
struct collection {
const char *name;
const char *summary;
struct bench *benchmarks;
};
static struct collection collections[] = {
{ "sched", "Scheduler and IPC benchmarks", sched_benchmarks },
{ "syscall", "System call benchmarks", syscall_benchmarks },
{ "mem", "Memory access benchmarks", mem_benchmarks },
#ifdef HAVE_LIBNUMA_SUPPORT
{ "numa", "NUMA scheduling and MM benchmarks", numa_benchmarks },
#endif
{"futex", "Futex stressing benchmarks", futex_benchmarks },
#ifdef HAVE_EVENTFD_SUPPORT
{"epoll", "Epoll stressing benchmarks", epoll_benchmarks },
#endif
{ "internals", "Perf-internals benchmarks", internals_benchmarks },
{ "breakpoint", "Breakpoint benchmarks", breakpoint_benchmarks },
{ "all", "All benchmarks", NULL },
{ NULL, NULL, NULL }
};
/* Iterate over all benchmark collections: */
#define for_each_collection(coll) \
for (coll = collections; coll->name; coll++)
/* Iterate over all benchmarks within a collection: */
#define for_each_bench(coll, bench) \
for (bench = coll->benchmarks; bench && bench->name; bench++)
static void dump_benchmarks(struct collection *coll)
{
struct bench *bench;
printf("\n # List of available benchmarks for collection '%s':\n\n", coll->name);
for_each_bench(coll, bench)
printf("%14s: %s\n", bench->name, bench->summary);
printf("\n");
}
static const char *bench_format_str;
/* Output/formatting style, exported to benchmark modules: */
int bench_format = BENCH_FORMAT_DEFAULT;
unsigned int bench_repeat = 10; /* default number of times to repeat the run */
static const struct option bench_options[] = {
OPT_STRING('f', "format", &bench_format_str, "default|simple", "Specify the output formatting style"),
OPT_UINTEGER('r', "repeat", &bench_repeat, "Specify amount of times to repeat the run"),
OPT_END()
};
static const char * const bench_usage[] = {
"perf bench [<common options>] <collection> <benchmark> [<options>]",
NULL
};
static void print_usage(void)
{
struct collection *coll;
int i;
printf("Usage: \n");
for (i = 0; bench_usage[i]; i++)
printf("\t%s\n", bench_usage[i]);
printf("\n");
printf(" # List of all available benchmark collections:\n\n");
for_each_collection(coll)
printf("%14s: %s\n", coll->name, coll->summary);
printf("\n");
}
static int bench_str2int(const char *str)
{
if (!str)
return BENCH_FORMAT_DEFAULT;
if (!strcmp(str, BENCH_FORMAT_DEFAULT_STR))
return BENCH_FORMAT_DEFAULT;
else if (!strcmp(str, BENCH_FORMAT_SIMPLE_STR))
return BENCH_FORMAT_SIMPLE;
return BENCH_FORMAT_UNKNOWN;
}
/*
* Run a specific benchmark but first rename the running task's ->comm[]
* to something meaningful:
*/
static int run_bench(const char *coll_name, const char *bench_name, bench_fn_t fn,
int argc, const char **argv)
{
int size;
char *name;
int ret;
size = strlen(coll_name) + 1 + strlen(bench_name) + 1;
name = zalloc(size);
BUG_ON(!name);
scnprintf(name, size, "%s-%s", coll_name, bench_name);
prctl(PR_SET_NAME, name);
argv[0] = name;
ret = fn(argc, argv);
free(name);
return ret;
}
static void run_collection(struct collection *coll)
{
struct bench *bench;
const char *argv[2];
argv[1] = NULL;
/*
* TODO:
*
* Preparing preset parameters for
* embedded, ordinary PC, HPC, etc...
* would be helpful.
*/
for_each_bench(coll, bench) {
if (!bench->fn)
break;
printf("# Running %s/%s benchmark...\n", coll->name, bench->name);
argv[1] = bench->name;
run_bench(coll->name, bench->name, bench->fn, 1, argv);
printf("\n");
}
}
static void run_all_collections(void)
{
struct collection *coll;
for_each_collection(coll)
run_collection(coll);
}
int cmd_bench(int argc, const char **argv)
{
struct collection *coll;
int ret = 0;
/* Unbuffered output */
setvbuf(stdout, NULL, _IONBF, 0);
if (argc < 2) {
/* No collection specified. */
print_usage();
goto end;
}
argc = parse_options(argc, argv, bench_options, bench_usage,
PARSE_OPT_STOP_AT_NON_OPTION);
bench_format = bench_str2int(bench_format_str);
if (bench_format == BENCH_FORMAT_UNKNOWN) {
printf("Unknown format descriptor: '%s'\n", bench_format_str);
goto end;
}
if (bench_repeat == 0) {
printf("Invalid repeat option: Must specify a positive value\n");
goto end;
}
if (argc < 1) {
print_usage();
goto end;
}
if (!strcmp(argv[0], "all")) {
run_all_collections();
goto end;
}
for_each_collection(coll) {
struct bench *bench;
if (strcmp(coll->name, argv[0]))
continue;
if (argc < 2) {
/* No bench specified. */
dump_benchmarks(coll);
goto end;
}
if (!strcmp(argv[1], "all")) {
run_collection(coll);
goto end;
}
for_each_bench(coll, bench) {
if (strcmp(bench->name, argv[1]))
continue;
if (bench_format == BENCH_FORMAT_DEFAULT)
printf("# Running '%s/%s' benchmark:\n", coll->name, bench->name);
ret = run_bench(coll->name, bench->name, bench->fn, argc-1, argv+1);
goto end;
}
if (!strcmp(argv[1], "-h") || !strcmp(argv[1], "--help")) {
dump_benchmarks(coll);
goto end;
}
printf("Unknown benchmark: '%s' for collection '%s'\n", argv[1], argv[0]);
ret = 1;
goto end;
}
printf("Unknown collection: '%s'\n", argv[0]);
ret = 1;
end:
return ret;
}