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(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171// 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(evlist)->nr_mmaps; i++) { struct mmap *map = &evlist__overwrite_mmap(evlist)[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__do_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__do_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 = { .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_put_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_put_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_put_evlist; }
ret = TEST_FAIL; err = do_test(evlist, opts.mmap_pages, &sample_count, &comm_count); if (err != TEST_OK) goto out_put_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_put_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_put_evlist; }
err = do_test(evlist, 1, &sample_count, &comm_count); if (err != TEST_OK) goto out_put_evlist;
ret = TEST_OK;out_put_evlist: evlist__put(evlist); return ret;}
DEFINE_SUITE("Read backward ring buffer", backward_ring_buffer);