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authorLinus Torvalds <torvalds@linux-foundation.org>2013-07-07 01:09:38 +0400
committerLinus Torvalds <torvalds@linux-foundation.org>2013-07-07 01:09:38 +0400
commit21884a83b2192a00885d7244a1dda32debd2fbc7 (patch)
treee00267bbcac32f0114b3d21a20c61107d2314c40 /tools
parent8b70a90cabafb6a6e1a0d3f838b38355fe48337e (diff)
parent73b0cd674ccc64c921e25bd7154f26d342116539 (diff)
downloadlinux-21884a83b2192a00885d7244a1dda32debd2fbc7.tar.xz
Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer core updates from Thomas Gleixner: "The timer changes contain: - posix timer code consolidation and fixes for odd corner cases - sched_clock implementation moved from ARM to core code to avoid duplication by other architectures - alarm timer updates - clocksource and clockevents unregistration facilities - clocksource/events support for new hardware - precise nanoseconds RTC readout (Xen feature) - generic support for Xen suspend/resume oddities - the usual lot of fixes and cleanups all over the place The parts which touch other areas (ARM/XEN) have been coordinated with the relevant maintainers. Though this results in an handful of trivial to solve merge conflicts, which we preferred over nasty cross tree merge dependencies. The patches which have been committed in the last few days are bug fixes plus the posix timer lot. The latter was in akpms queue and next for quite some time; they just got forgotten and Frederic collected them last minute." * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (59 commits) hrtimer: Remove unused variable hrtimers: Move SMP function call to thread context clocksource: Reselect clocksource when watchdog validated high-res capability posix-cpu-timers: don't account cpu timer after stopped thread runtime accounting posix_timers: fix racy timer delta caching on task exit posix-timers: correctly get dying task time sample in posix_cpu_timer_schedule() selftests: add basic posix timers selftests posix_cpu_timers: consolidate expired timers check posix_cpu_timers: consolidate timer list cleanups posix_cpu_timer: consolidate expiry time type tick: Sanitize broadcast control logic tick: Prevent uncontrolled switch to oneshot mode tick: Make oneshot broadcast robust vs. CPU offlining x86: xen: Sync the CMOS RTC as well as the Xen wallclock x86: xen: Sync the wallclock when the system time is set timekeeping: Indicate that clock was set in the pvclock gtod notifier timekeeping: Pass flags instead of multiple bools to timekeeping_update() xen: Remove clock_was_set() call in the resume path hrtimers: Support resuming with two or more CPUs online (but stopped) timer: Fix jiffies wrap behavior of round_jiffies_common() ...
Diffstat (limited to 'tools')
-rw-r--r--tools/testing/selftests/Makefile1
-rw-r--r--tools/testing/selftests/timers/Makefile8
-rw-r--r--tools/testing/selftests/timers/posix_timers.c221
3 files changed, 230 insertions, 0 deletions
diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
index 0a63658065f0..4cb14cae3791 100644
--- a/tools/testing/selftests/Makefile
+++ b/tools/testing/selftests/Makefile
@@ -6,6 +6,7 @@ TARGETS += memory-hotplug
TARGETS += mqueue
TARGETS += net
TARGETS += ptrace
+TARGETS += timers
TARGETS += vm
all:
diff --git a/tools/testing/selftests/timers/Makefile b/tools/testing/selftests/timers/Makefile
new file mode 100644
index 000000000000..eb2859f4ad21
--- /dev/null
+++ b/tools/testing/selftests/timers/Makefile
@@ -0,0 +1,8 @@
+all:
+ gcc posix_timers.c -o posix_timers -lrt
+
+run_tests: all
+ ./posix_timers
+
+clean:
+ rm -f ./posix_timers
diff --git a/tools/testing/selftests/timers/posix_timers.c b/tools/testing/selftests/timers/posix_timers.c
new file mode 100644
index 000000000000..4fa655d68a81
--- /dev/null
+++ b/tools/testing/selftests/timers/posix_timers.c
@@ -0,0 +1,221 @@
+/*
+ * Copyright (C) 2013 Red Hat, Inc., Frederic Weisbecker <fweisbec@redhat.com>
+ *
+ * Licensed under the terms of the GNU GPL License version 2
+ *
+ * Selftests for a few posix timers interface.
+ *
+ * Kernel loop code stolen from Steven Rostedt <srostedt@redhat.com>
+ */
+
+#include <sys/time.h>
+#include <stdio.h>
+#include <signal.h>
+#include <unistd.h>
+#include <time.h>
+#include <pthread.h>
+
+#define DELAY 2
+#define USECS_PER_SEC 1000000
+
+static volatile int done;
+
+/* Busy loop in userspace to elapse ITIMER_VIRTUAL */
+static void user_loop(void)
+{
+ while (!done);
+}
+
+/*
+ * Try to spend as much time as possible in kernelspace
+ * to elapse ITIMER_PROF.
+ */
+static void kernel_loop(void)
+{
+ void *addr = sbrk(0);
+
+ while (!done) {
+ brk(addr + 4096);
+ brk(addr);
+ }
+}
+
+/*
+ * Sleep until ITIMER_REAL expiration.
+ */
+static void idle_loop(void)
+{
+ pause();
+}
+
+static void sig_handler(int nr)
+{
+ done = 1;
+}
+
+/*
+ * Check the expected timer expiration matches the GTOD elapsed delta since
+ * we armed the timer. Keep a 0.5 sec error margin due to various jitter.
+ */
+static int check_diff(struct timeval start, struct timeval end)
+{
+ long long diff;
+
+ diff = end.tv_usec - start.tv_usec;
+ diff += (end.tv_sec - start.tv_sec) * USECS_PER_SEC;
+
+ if (abs(diff - DELAY * USECS_PER_SEC) > USECS_PER_SEC / 2) {
+ printf("Diff too high: %lld..", diff);
+ return -1;
+ }
+
+ return 0;
+}
+
+static int check_itimer(int which)
+{
+ int err;
+ struct timeval start, end;
+ struct itimerval val = {
+ .it_value.tv_sec = DELAY,
+ };
+
+ printf("Check itimer ");
+
+ if (which == ITIMER_VIRTUAL)
+ printf("virtual... ");
+ else if (which == ITIMER_PROF)
+ printf("prof... ");
+ else if (which == ITIMER_REAL)
+ printf("real... ");
+
+ fflush(stdout);
+
+ done = 0;
+
+ if (which == ITIMER_VIRTUAL)
+ signal(SIGVTALRM, sig_handler);
+ else if (which == ITIMER_PROF)
+ signal(SIGPROF, sig_handler);
+ else if (which == ITIMER_REAL)
+ signal(SIGALRM, sig_handler);
+
+ err = gettimeofday(&start, NULL);
+ if (err < 0) {
+ perror("Can't call gettimeofday()\n");
+ return -1;
+ }
+
+ err = setitimer(which, &val, NULL);
+ if (err < 0) {
+ perror("Can't set timer\n");
+ return -1;
+ }
+
+ if (which == ITIMER_VIRTUAL)
+ user_loop();
+ else if (which == ITIMER_PROF)
+ kernel_loop();
+ else if (which == ITIMER_REAL)
+ idle_loop();
+
+ gettimeofday(&end, NULL);
+ if (err < 0) {
+ perror("Can't call gettimeofday()\n");
+ return -1;
+ }
+
+ if (!check_diff(start, end))
+ printf("[OK]\n");
+ else
+ printf("[FAIL]\n");
+
+ return 0;
+}
+
+static int check_timer_create(int which)
+{
+ int err;
+ timer_t id;
+ struct timeval start, end;
+ struct itimerspec val = {
+ .it_value.tv_sec = DELAY,
+ };
+
+ printf("Check timer_create() ");
+ if (which == CLOCK_THREAD_CPUTIME_ID) {
+ printf("per thread... ");
+ } else if (which == CLOCK_PROCESS_CPUTIME_ID) {
+ printf("per process... ");
+ }
+ fflush(stdout);
+
+ done = 0;
+ timer_create(which, NULL, &id);
+ if (err < 0) {
+ perror("Can't create timer\n");
+ return -1;
+ }
+ signal(SIGALRM, sig_handler);
+
+ err = gettimeofday(&start, NULL);
+ if (err < 0) {
+ perror("Can't call gettimeofday()\n");
+ return -1;
+ }
+
+ err = timer_settime(id, 0, &val, NULL);
+ if (err < 0) {
+ perror("Can't set timer\n");
+ return -1;
+ }
+
+ user_loop();
+
+ gettimeofday(&end, NULL);
+ if (err < 0) {
+ perror("Can't call gettimeofday()\n");
+ return -1;
+ }
+
+ if (!check_diff(start, end))
+ printf("[OK]\n");
+ else
+ printf("[FAIL]\n");
+
+ return 0;
+}
+
+int main(int argc, char **argv)
+{
+ int err;
+
+ printf("Testing posix timers. False negative may happen on CPU execution \n");
+ printf("based timers if other threads run on the CPU...\n");
+
+ if (check_itimer(ITIMER_VIRTUAL) < 0)
+ return -1;
+
+ if (check_itimer(ITIMER_PROF) < 0)
+ return -1;
+
+ if (check_itimer(ITIMER_REAL) < 0)
+ return -1;
+
+ if (check_timer_create(CLOCK_THREAD_CPUTIME_ID) < 0)
+ return -1;
+
+ /*
+ * It's unfortunately hard to reliably test a timer expiration
+ * on parallel multithread cputime. We could arm it to expire
+ * on DELAY * nr_threads, with nr_threads busy looping, then wait
+ * the normal DELAY since the time is elapsing nr_threads faster.
+ * But for that we need to ensure we have real physical free CPUs
+ * to ensure true parallelism. So test only one thread until we
+ * find a better solution.
+ */
+ if (check_timer_create(CLOCK_PROCESS_CPUTIME_ID) < 0)
+ return -1;
+
+ return 0;
+}