diff options
Diffstat (limited to 'tools/perf/tests/backward-ring-buffer.c')
| -rw-r--r-- | tools/perf/tests/backward-ring-buffer.c | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/tools/perf/tests/backward-ring-buffer.c b/tools/perf/tests/backward-ring-buffer.c new file mode 100644 index 000000000..79a980b1e --- /dev/null +++ b/tools/perf/tests/backward-ring-buffer.c @@ -0,0 +1,171 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Test backward bit in event attribute, read ring buffer from end to + * beginning + */ + +#include <evlist.h> +#include <sys/prctl.h> +#include "record.h" +#include "tests.h" +#include "debug.h" +#include "parse-events.h" +#include "util/mmap.h" +#include <errno.h> +#include <linux/string.h> +#include <perf/mmap.h> + +#define NR_ITERS 111 + +static void testcase(void) +{ + int i; + + for (i = 0; i < NR_ITERS; i++) { + char proc_name[15]; + + snprintf(proc_name, sizeof(proc_name), "p:%d\n", i); + prctl(PR_SET_NAME, proc_name); + } +} + +static int count_samples(struct evlist *evlist, int *sample_count, + int *comm_count) +{ + int i; + + for (i = 0; i < evlist->core.nr_mmaps; i++) { + struct mmap *map = &evlist->overwrite_mmap[i]; + union perf_event *event; + + perf_mmap__read_init(&map->core); + while ((event = perf_mmap__read_event(&map->core)) != NULL) { + const u32 type = event->header.type; + + switch (type) { + case PERF_RECORD_SAMPLE: + (*sample_count)++; + break; + case PERF_RECORD_COMM: + (*comm_count)++; + break; + default: + pr_err("Unexpected record of type %d\n", type); + return TEST_FAIL; + } + } + perf_mmap__read_done(&map->core); + } + return TEST_OK; +} + +static int do_test(struct evlist *evlist, int mmap_pages, + int *sample_count, int *comm_count) +{ + int err; + char sbuf[STRERR_BUFSIZE]; + + err = evlist__mmap(evlist, mmap_pages); + if (err < 0) { + pr_debug("evlist__mmap: %s\n", + str_error_r(errno, sbuf, sizeof(sbuf))); + return TEST_FAIL; + } + + evlist__enable(evlist); + testcase(); + evlist__disable(evlist); + + err = count_samples(evlist, sample_count, comm_count); + evlist__munmap(evlist); + return err; +} + + +static int test__backward_ring_buffer(struct test_suite *test __maybe_unused, int subtest __maybe_unused) +{ + int ret = TEST_SKIP, err, sample_count = 0, comm_count = 0; + char pid[16], sbuf[STRERR_BUFSIZE]; + struct evlist *evlist; + struct evsel *evsel __maybe_unused; + struct parse_events_error parse_error; + struct record_opts opts = { + .target = { + .uid = UINT_MAX, + .uses_mmap = true, + }, + .freq = 0, + .mmap_pages = 256, + .default_interval = 1, + }; + + snprintf(pid, sizeof(pid), "%d", getpid()); + pid[sizeof(pid) - 1] = '\0'; + opts.target.tid = opts.target.pid = pid; + + evlist = evlist__new(); + if (!evlist) { + pr_debug("Not enough memory to create evlist\n"); + return TEST_FAIL; + } + + err = evlist__create_maps(evlist, &opts.target); + if (err < 0) { + pr_debug("Not enough memory to create thread/cpu maps\n"); + goto out_delete_evlist; + } + + parse_events_error__init(&parse_error); + /* + * Set backward bit, ring buffer should be writing from end. Record + * it in aux evlist + */ + err = parse_events(evlist, "syscalls:sys_enter_prctl/overwrite/", &parse_error); + parse_events_error__exit(&parse_error); + if (err) { + pr_debug("Failed to parse tracepoint event, try use root\n"); + ret = TEST_SKIP; + goto out_delete_evlist; + } + + evlist__config(evlist, &opts, NULL); + + err = evlist__open(evlist); + if (err < 0) { + pr_debug("perf_evlist__open: %s\n", + str_error_r(errno, sbuf, sizeof(sbuf))); + goto out_delete_evlist; + } + + ret = TEST_FAIL; + err = do_test(evlist, opts.mmap_pages, &sample_count, + &comm_count); + if (err != TEST_OK) + goto out_delete_evlist; + + if ((sample_count != NR_ITERS) || (comm_count != NR_ITERS)) { + pr_err("Unexpected counter: sample_count=%d, comm_count=%d\n", + sample_count, comm_count); + goto out_delete_evlist; + } + + evlist__close(evlist); + + err = evlist__open(evlist); + if (err < 0) { + pr_debug("perf_evlist__open: %s\n", + str_error_r(errno, sbuf, sizeof(sbuf))); + goto out_delete_evlist; + } + + err = do_test(evlist, 1, &sample_count, &comm_count); + if (err != TEST_OK) + goto out_delete_evlist; + + ret = TEST_OK; +out_delete_evlist: + evlist__delete(evlist); + return ret; +} + +DEFINE_SUITE("Read backward ring buffer", backward_ring_buffer); |