/* * Copyright (C) 2016 Google, Inc. * * This software is licensed under the terms of the GNU General Public * License version 2, as published by the Free Software Foundation, and * may be copied, distributed, and modified under those terms. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * */ #define _GNU_SOURCE #include #include #include #include #include #include #include #include #include #include #include #include #include #include "../kselftest.h" void child(int cpu) { cpu_set_t set; CPU_ZERO(&set); CPU_SET(cpu, &set); if (sched_setaffinity(0, sizeof(set), &set) != 0) { perror("sched_setaffinity() failed"); _exit(1); } if (ptrace(PTRACE_TRACEME, 0, NULL, NULL) != 0) { perror("ptrace(PTRACE_TRACEME) failed"); _exit(1); } if (raise(SIGSTOP) != 0) { perror("raise(SIGSTOP) failed"); _exit(1); } _exit(0); } bool run_test(int cpu) { int status; pid_t pid = fork(); pid_t wpid; if (pid < 0) { perror("fork() failed"); return false; } if (pid == 0) child(cpu); wpid = waitpid(pid, &status, __WALL); if (wpid != pid) { perror("waitpid() failed"); return false; } if (!WIFSTOPPED(status)) { printf("child did not stop\n"); return false; } if (WSTOPSIG(status) != SIGSTOP) { printf("child did not stop with SIGSTOP\n"); return false; } if (ptrace(PTRACE_SINGLESTEP, pid, NULL, NULL) < 0) { if (errno == EIO) { printf("ptrace(PTRACE_SINGLESTEP) not supported on this architecture\n"); ksft_exit_skip(); } perror("ptrace(PTRACE_SINGLESTEP) failed"); return false; } wpid = waitpid(pid, &status, __WALL); if (wpid != pid) { perror("waitpid() failed"); return false; } if (WIFEXITED(status)) { printf("child did not single-step\n"); return false; } if (!WIFSTOPPED(status)) { printf("child did not stop\n"); return false; } if (WSTOPSIG(status) != SIGTRAP) { printf("child did not stop with SIGTRAP\n"); return false; } if (ptrace(PTRACE_CONT, pid, NULL, NULL) < 0) { perror("ptrace(PTRACE_CONT) failed"); return false; } wpid = waitpid(pid, &status, __WALL); if (wpid != pid) { perror("waitpid() failed"); return false; } if (!WIFEXITED(status)) { printf("child did not exit after PTRACE_CONT\n"); return false; } return true; } void suspend(void) { int power_state_fd; struct sigevent event = {}; int timerfd; int err; struct itimerspec spec = {}; power_state_fd = open("/sys/power/state", O_RDWR); if (power_state_fd < 0) { perror("open(\"/sys/power/state\") failed (is this test running as root?)"); ksft_exit_fail(); } timerfd = timerfd_create(CLOCK_BOOTTIME_ALARM, 0); if (timerfd < 0) { perror("timerfd_create() failed"); ksft_exit_fail(); } spec.it_value.tv_sec = 5; err = timerfd_settime(timerfd, 0, &spec, NULL); if (err < 0) { perror("timerfd_settime() failed"); ksft_exit_fail(); } if (write(power_state_fd, "mem", strlen("mem")) != strlen("mem")) { perror("entering suspend failed"); ksft_exit_fail(); } close(timerfd); close(power_state_fd); } int main(int argc, char **argv) { int opt; bool do_suspend = true; bool succeeded = true; cpu_set_t available_cpus; int err; int cpu; while ((opt = getopt(argc, argv, "n")) != -1) { switch (opt) { case 'n': do_suspend = false; break; default: printf("Usage: %s [-n]\n", argv[0]); printf(" -n: do not trigger a suspend/resume cycle before the test\n"); return -1; } } if (do_suspend) suspend(); err = sched_getaffinity(0, sizeof(available_cpus), &available_cpus); if (err < 0) { perror("sched_getaffinity() failed"); ksft_exit_fail(); } for (cpu = 0; cpu < CPU_SETSIZE; cpu++) { bool test_success; if (!CPU_ISSET(cpu, &available_cpus)) continue; test_success = run_test(cpu); printf("CPU %d: ", cpu); if (test_success) { printf("[OK]\n"); ksft_inc_pass_cnt(); } else { printf("[FAILED]\n"); ksft_inc_fail_cnt(); succeeded = false; } } ksft_print_cnts(); if (succeeded) ksft_exit_pass(); else ksft_exit_fail(); } /td>space:mode:
authorSteven Rostedt (VMware) <rostedt@goodmis.org>2017-01-30 19:27:10 -0500
committerSteven Rostedt (VMware) <rostedt@goodmis.org>2017-01-31 09:13:49 -0500
commit79c6f448c8b79c321e4a1f31f98194e4f6b6cae7 (patch)
tree370efda701f03cccf21e02bb1fdd3b852547d75c /sound/pci/nm256/Makefile
parent0c744ea4f77d72b3dcebb7a8f2684633ec79be88 (diff)
tracing: Fix hwlat kthread migration
The hwlat tracer creates a kernel thread at start of the tracer. It is pinned to a single CPU and will move to the next CPU after each period of running. If the user modifies the migration thread's affinity, it will not change after that happens. The original code created the thread at the first instance it was called, but later was changed to destroy the thread after the tracer was finished, and would not be created until the next instance of the tracer was established. The code that initialized the affinity was only called on the initial instantiation of the tracer. After that, it was not initialized, and the previous affinity did not match the current newly created one, making it appear that the user modified the thread's affinity when it did not, and the thread failed to migrate again. Cc: stable@vger.kernel.org Fixes: 0330f7aa8ee6 ("tracing: Have hwlat trace migrate across tracing_cpumask CPUs") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'sound/pci/nm256/Makefile')