diff --git a/tools/perf/Documentation/perf-test.txt b/tools/perf/Documentation/perf-test.txt index 32da0d1fa86a..2f4a91f5b9dc 100644 --- a/tools/perf/Documentation/perf-test.txt +++ b/tools/perf/Documentation/perf-test.txt @@ -69,3 +69,15 @@ OPTIONS --list-workloads:: List the available workloads to use with -w/--workload. + +--record-ctl=fifo:ctl-fifo[,ack-fifo]:: + This option is used to communicate with a perf record session in order + to control the recording scope to only the workload and avoid recording + setup and teardown code. When specifying this option, the same FIFO path + must be specified in the record session via: + + perf record -D -1 --control=fifo:ctl-fifo[,ack-fifo] ... + + Perf test sends 'enable' and 'disable' commands through ctl-fifo to + control event recording. If 'ack-fifo' is provided, the workload runner + waits for an 'ack' response after each command. diff --git a/tools/perf/tests/builtin-test.c b/tools/perf/tests/builtin-test.c index b64fc2204f22..86ea427eb0aa 100644 --- a/tools/perf/tests/builtin-test.c +++ b/tools/perf/tests/builtin-test.c @@ -56,6 +56,7 @@ static unsigned int runs_per_test = 1; static unsigned int failure_snippet_lines = 10; const char *dso_to_test; const char *test_objdump_path = "objdump"; +static const char *workload_control; /* * List of architecture specific tests. Not a weak symbol as the array length is @@ -168,6 +169,11 @@ static struct test_workload *workloads[] = { #endif }; +struct workload_control { + int ctl_fd; + int ack_fd; +}; + #define workloads__for_each(workload) \ for (unsigned i = 0; i < ARRAY_SIZE(workloads) && ({ workload = workloads[i]; 1; }); i++) @@ -1387,13 +1393,185 @@ static int workloads__fprintf_list(FILE *fp) return printed; } +static int perf_control_open_fifo(struct workload_control *ctl, const char *str) +{ + char *s, *p; + int ret; + + if (strncmp(str, "fifo:", 5)) + return -EINVAL; + + str += 5; + if (!*str || *str == ',') + return -EINVAL; + + s = strdup(str); + if (!s) + return -ENOMEM; + + p = strchr(s, ','); + if (p) + *p = '\0'; + + ctl->ctl_fd = open(s, O_WRONLY | O_CLOEXEC); + if (ctl->ctl_fd < 0) { + ret = -errno; + pr_err("Failed to open workload control FIFO '%s': %m\n", s); + free(s); + return ret; + } + + if (p && *++p) { + ctl->ack_fd = open(p, O_RDONLY | O_CLOEXEC); + if (ctl->ack_fd < 0) { + ret = -errno; + pr_err("Failed to open workload control ack FIFO '%s': %m\n", p); + close(ctl->ctl_fd); + ctl->ctl_fd = -1; + free(s); + return ret; + } + } + + free(s); + return 0; +} + +static int perf_control_open(struct workload_control *ctl) +{ + int ret; + + if (!workload_control) + return 0; + + ret = perf_control_open_fifo(ctl, workload_control); + + if (ret == -EINVAL) { + pr_err("Unsupported workload control spec '%s', expected fifo:ctl-fifo[,ack-fifo]\n", + workload_control); + } + + return ret; +} + +static void perf_control_close(struct workload_control *ctl) +{ + if (ctl->ctl_fd >= 0) { + close(ctl->ctl_fd); + ctl->ctl_fd = -1; + } + if (ctl->ack_fd >= 0) { + close(ctl->ack_fd); + ctl->ack_fd = -1; + } +} + +static int perf_control_write_cmd(int fd, const char *cmd) +{ + size_t len = strlen(cmd); + ssize_t ret; + + while (len) { + ret = write(fd, cmd, len); + if (ret < 0) { + if (errno == EINTR) + continue; + pr_err("Failed to write perf control command: %m\n"); + return -1; + } + + if (!ret) { + pr_err("Failed to write perf control command: short write\n"); + return -1; + } + + cmd += ret; + len -= ret; + } + + return 0; +} + +static int perf_control_read_ack(int fd) +{ + char buf[16]; + ssize_t ret; + + do { + ret = read(fd, buf, sizeof(buf) - 1); + } while (ret < 0 && errno == EINTR); + + if (ret < 0) { + pr_err("Failed to read perf control ack: %m\n"); + return -1; + } + + if (!ret) { + pr_err("Unexpected EOF while reading perf control ack\n"); + return -1; + } + + buf[ret] = '\0'; + for (ssize_t i = 0; i < ret; i++) { + if (buf[i] == '\n' || buf[i] == '\0') { + buf[i] = '\0'; + break; + } + } + + if (strcmp(buf, "ack")) { + pr_err("Unexpected perf control ack: %s\n", buf); + return -1; + } + + return 0; +} + +static int perf_control_send(struct workload_control *ctl, const char *cmd) +{ + if (ctl->ctl_fd < 0) + return 0; + + if (perf_control_write_cmd(ctl->ctl_fd, cmd)) + return -1; + + if (ctl->ack_fd >= 0 && perf_control_read_ack(ctl->ack_fd)) + return -1; + + return 0; +} + static int run_workload(const char *work, int argc, const char **argv) { struct test_workload *twl; workloads__for_each(twl) { - if (!strcmp(twl->name, work)) - return twl->func(argc, argv); + struct workload_control ctl = { + .ctl_fd = -1, + .ack_fd = -1, + }; + int control_ret, ret; + + if (strcmp(twl->name, work)) + continue; + + ret = perf_control_open(&ctl); + if (ret) + return ret; + + if (perf_control_send(&ctl, "enable\n")) { + perf_control_close(&ctl); + return -1; + } + + ret = twl->func(argc, argv); + + control_ret = perf_control_send(&ctl, "disable\n"); + perf_control_close(&ctl); + if (control_ret) + return -1; + + return ret; } pr_info("No workload found: %s\n", work); @@ -1486,6 +1664,8 @@ int cmd_test(int argc, const char **argv) OPT_UINTEGER('r', "runs-per-test", &runs_per_test, "Run each test the given number of times, default 1"), OPT_STRING('w', "workload", &workload, "work", "workload to run for testing, use '--list-workloads' to list the available ones."), + OPT_STRING(0, "record-ctl", &workload_control, "fifo:ctl-fifo[,ack-fifo]", + "Write enable to the fifo just before running the workload and disable after, with optional ack from ack-fifo"), OPT_BOOLEAN(0, "list-workloads", &list_workloads, "List the available builtin workloads to use with -w/--workload"), OPT_STRING(0, "dso", &dso_to_test, "dso", "dso to test"), OPT_STRING(0, "objdump", &test_objdump_path, "path",