* [PATCH v1 0/3] selftests/timers/posix_timers: various cleanups
@ 2024-03-04 18:11 Edward Liaw
2024-03-04 18:11 ` [PATCH v1 1/3] selftests/timers/posix_timers: Make signal distribution test less fragile Edward Liaw
` (3 more replies)
0 siblings, 4 replies; 6+ messages in thread
From: Edward Liaw @ 2024-03-04 18:11 UTC (permalink / raw
To: linux-kernel, John Stultz, Thomas Gleixner, Stephen Boyd,
Shuah Khan, Nathan Chancellor, Nick Desaulniers, Bill Wendling,
Justin Stitt
Cc: linux-kselftest, kernel-team, Edward Liaw, llvm
I'm sending some patches that were orignally in
https://lore.kernel.org/lkml/20230606132949.068951363@linutronix.de/
to prevent the timer_distribution test from hanging and also fix some
format inconsistencies.
Edward Liaw (3):
selftests/timers/posix_timers: Make signal distribution test less
fragile
selftests/timers/posix_timers: Use TAP reporting format
selftests/timers/posix_timers: Use llabs for long long
tools/testing/selftests/timers/posix_timers.c | 196 ++++++++----------
1 file changed, 89 insertions(+), 107 deletions(-)
--
2.44.0.rc1.240.g4c46232300-goog
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH v1 1/3] selftests/timers/posix_timers: Make signal distribution test less fragile
2024-03-04 18:11 [PATCH v1 0/3] selftests/timers/posix_timers: various cleanups Edward Liaw
@ 2024-03-04 18:11 ` Edward Liaw
2024-03-04 18:11 ` [PATCH v1 2/3] selftests/timers/posix_timers: Use TAP reporting format Edward Liaw
` (2 subsequent siblings)
3 siblings, 0 replies; 6+ messages in thread
From: Edward Liaw @ 2024-03-04 18:11 UTC (permalink / raw
To: linux-kernel, John Stultz, Thomas Gleixner, Stephen Boyd,
Shuah Khan, Nathan Chancellor, Nick Desaulniers, Bill Wendling,
Justin Stitt
Cc: linux-kselftest, kernel-team, Edward Liaw, llvm
The signal distribution test has a tendency to hang for a long time as the
signal delivery is not really evenly distributed.
Increasing the timer interval to 10ms makes this less likely. Add a timeout
to catch the case where it hangs and terminate the test gracefully.
While at it get rid of the pointless atomic operation on a the thread local
variable in the signal handler.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[edliaw: Rebase and fix checkpatch recommendations]
Signed-off-by: Edward Liaw <edliaw@google.com>
---
tools/testing/selftests/timers/posix_timers.c | 43 ++++++++++++-------
1 file changed, 27 insertions(+), 16 deletions(-)
diff --git a/tools/testing/selftests/timers/posix_timers.c b/tools/testing/selftests/timers/posix_timers.c
index d49dd3ffd0d9..03779b6b3c20 100644
--- a/tools/testing/selftests/timers/posix_timers.c
+++ b/tools/testing/selftests/timers/posix_timers.c
@@ -24,7 +24,8 @@ static volatile int done;
/* Busy loop in userspace to elapse ITIMER_VIRTUAL */
static void user_loop(void)
{
- while (!done);
+ while (!done)
+ continue;
}
/*
@@ -184,18 +185,19 @@ static int check_timer_create(int which)
return 0;
}
-int remain;
-__thread int got_signal;
+static int remain;
+static __thread int got_signal;
static void *distribution_thread(void *arg)
{
- while (__atomic_load_n(&remain, __ATOMIC_RELAXED));
+ while (__atomic_load_n(&remain, __ATOMIC_RELAXED) && !done)
+ continue;
return NULL;
}
static void distribution_handler(int nr)
{
- if (!__atomic_exchange_n(&got_signal, 1, __ATOMIC_RELAXED))
+ if (++got_signal == 1)
__atomic_fetch_sub(&remain, 1, __ATOMIC_RELAXED);
}
@@ -205,17 +207,19 @@ static void distribution_handler(int nr)
*/
static int check_timer_distribution(void)
{
- int err, i;
- timer_t id;
const int nthreads = 10;
pthread_t threads[nthreads];
struct itimerspec val = {
.it_value.tv_sec = 0,
- .it_value.tv_nsec = 1000 * 1000,
+ .it_value.tv_nsec = 20 * 1000 * 1000,
.it_interval.tv_sec = 0,
- .it_interval.tv_nsec = 1000 * 1000,
+ .it_interval.tv_nsec = 20 * 1000 * 1000,
};
+ time_t start, now;
+ int err, i;
+ timer_t id;
+ done = 0;
remain = nthreads + 1; /* worker threads + this thread */
signal(SIGALRM, distribution_handler);
err = timer_create(CLOCK_PROCESS_CPUTIME_ID, NULL, &id);
@@ -240,7 +244,18 @@ static int check_timer_distribution(void)
}
/* Wait for all threads to receive the signal. */
- while (__atomic_load_n(&remain, __ATOMIC_RELAXED));
+ now = start = time(NULL);
+ while (__atomic_load_n(&remain, __ATOMIC_RELAXED)) {
+ now = time(NULL);
+ if (now - start > 5)
+ break;
+ }
+ done = 1;
+
+ if (timer_delete(id)) {
+ ksft_perror("Can't delete timer\n");
+ return -1;
+ }
for (i = 0; i < nthreads; i++) {
err = pthread_join(threads[i], NULL);
@@ -251,12 +266,8 @@ static int check_timer_distribution(void)
}
}
- if (timer_delete(id)) {
- ksft_perror("Can't delete timer");
- return -1;
- }
+ ksft_test_result((now - start <= 5), "%s\n", __func__);
- ksft_test_result_pass("check_timer_distribution\n");
return 0;
}
@@ -265,7 +276,7 @@ int main(int argc, char **argv)
ksft_print_header();
ksft_set_plan(6);
- ksft_print_msg("Testing posix timers. False negative may happen on CPU execution \n");
+ ksft_print_msg("Testing posix timers. False negative may happen on CPU execution\n");
ksft_print_msg("based timers if other threads run on the CPU...\n");
if (check_itimer(ITIMER_VIRTUAL) < 0)
--
2.44.0.rc1.240.g4c46232300-goog
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH v1 2/3] selftests/timers/posix_timers: Use TAP reporting format
2024-03-04 18:11 [PATCH v1 0/3] selftests/timers/posix_timers: various cleanups Edward Liaw
2024-03-04 18:11 ` [PATCH v1 1/3] selftests/timers/posix_timers: Make signal distribution test less fragile Edward Liaw
@ 2024-03-04 18:11 ` Edward Liaw
2024-03-04 18:11 ` [PATCH v1 3/3] selftests/timers/posix_timers: Use llabs for long long Edward Liaw
2024-03-07 21:04 ` [PATCH v1 0/3] selftests/timers/posix_timers: various cleanups Thomas Gleixner
3 siblings, 0 replies; 6+ messages in thread
From: Edward Liaw @ 2024-03-04 18:11 UTC (permalink / raw
To: linux-kernel, John Stultz, Thomas Gleixner, Stephen Boyd,
Shuah Khan, Nathan Chancellor, Nick Desaulniers, Bill Wendling,
Justin Stitt
Cc: linux-kselftest, kernel-team, Edward Liaw, llvm
No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[edliaw: Fix checkpatch recommendations]
Signed-off-by: Edward Liaw <edliaw@google.com>
---
tools/testing/selftests/timers/posix_timers.c | 161 +++++++-----------
1 file changed, 66 insertions(+), 95 deletions(-)
diff --git a/tools/testing/selftests/timers/posix_timers.c b/tools/testing/selftests/timers/posix_timers.c
index 03779b6b3c20..0f550fc9e879 100644
--- a/tools/testing/selftests/timers/posix_timers.c
+++ b/tools/testing/selftests/timers/posix_timers.c
@@ -10,6 +10,7 @@
#include <sys/time.h>
#include <stdio.h>
#include <signal.h>
+#include <string.h>
#include <unistd.h>
#include <time.h>
#include <pthread.h>
@@ -19,6 +20,20 @@
#define DELAY 2
#define USECS_PER_SEC 1000000
+static void __fatal_error(const char *test, const char *name, const char *what)
+{
+ char buf[64];
+
+ strerror_r(errno, buf, sizeof(buf));
+
+ if (name && strlen(name))
+ ksft_exit_fail_msg("%s %s %s %s\n", test, name, what, buf);
+ else
+ ksft_exit_fail_msg("%s %s %s\n", test, what, buf);
+}
+
+#define fatal_error(name, what) __fatal_error(__func__, name, what)
+
static volatile int done;
/* Busy loop in userspace to elapse ITIMER_VIRTUAL */
@@ -67,15 +82,13 @@ static int check_diff(struct timeval start, struct timeval end)
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);
+ if (abs(diff - DELAY * USECS_PER_SEC) > USECS_PER_SEC / 2)
return -1;
- }
return 0;
}
-static int check_itimer(int which)
+static void check_itimer(int which)
{
const char *name;
int err;
@@ -91,7 +104,7 @@ static int check_itimer(int which)
else if (which == ITIMER_REAL)
name = "ITIMER_REAL";
else
- return -1;
+ ksft_exit_fail_msg("Unknown setitimer() type %d\n", which);
done = 0;
@@ -103,16 +116,12 @@ static int check_itimer(int which)
signal(SIGALRM, sig_handler);
err = gettimeofday(&start, NULL);
- if (err < 0) {
- ksft_perror("Can't call gettimeofday()");
- return -1;
- }
+ if (err < 0)
+ fatal_error(name, "gettimeofday()");
err = setitimer(which, &val, NULL);
- if (err < 0) {
- ksft_perror("Can't set timer");
- return -1;
- }
+ if (err < 0)
+ fatal_error(name, "setitimer()");
if (which == ITIMER_VIRTUAL)
user_loop();
@@ -122,19 +131,15 @@ static int check_itimer(int which)
idle_loop();
err = gettimeofday(&end, NULL);
- if (err < 0) {
- ksft_perror("Can't call gettimeofday()");
- return -1;
- }
+ if (err < 0)
+ fatal_error(name, "gettimeofday()");
- ksft_test_result(check_diff(start, end) == 0, "%s\n", name);
-
- return 0;
+ ksft_test_result(!check_diff(start, end), "%s %s\n", __func__, name);
}
-static int check_timer_create(int which)
+static void check_timer_create(int which)
{
- const char *type;
+ const char *name;
int err;
timer_t id;
struct timeval start, end;
@@ -142,47 +147,37 @@ static int check_timer_create(int which)
.it_value.tv_sec = DELAY,
};
- if (which == CLOCK_THREAD_CPUTIME_ID) {
- type = "thread";
- } else if (which == CLOCK_PROCESS_CPUTIME_ID) {
- type = "process";
- } else {
- ksft_print_msg("Unknown timer_create() type %d\n", which);
- return -1;
- }
+ if (which == CLOCK_THREAD_CPUTIME_ID)
+ name = "thread";
+ else if (which == CLOCK_PROCESS_CPUTIME_ID)
+ name = "process";
+ else
+ ksft_exit_fail_msg("Unknown timer_create() type %d\n", which);
done = 0;
err = timer_create(which, NULL, &id);
- if (err < 0) {
- ksft_perror("Can't create timer");
- return -1;
- }
- signal(SIGALRM, sig_handler);
+ if (err < 0)
+ fatal_error(name, "timer_create()");
+
+ if (signal(SIGALRM, sig_handler) == SIG_ERR)
+ fatal_error(name, "signal()");
err = gettimeofday(&start, NULL);
- if (err < 0) {
- ksft_perror("Can't call gettimeofday()");
- return -1;
- }
+ if (err < 0)
+ fatal_error(name, "gettimeofday()");
err = timer_settime(id, 0, &val, NULL);
- if (err < 0) {
- ksft_perror("Can't set timer");
- return -1;
- }
+ if (err < 0)
+ fatal_error(name, "timer_settime()");
user_loop();
err = gettimeofday(&end, NULL);
- if (err < 0) {
- ksft_perror("Can't call gettimeofday()");
- return -1;
- }
+ if (err < 0)
+ fatal_error(name, "gettimeofday()");
ksft_test_result(check_diff(start, end) == 0,
- "timer_create() per %s\n", type);
-
- return 0;
+ "%s %s\n", __func__, name);
}
static int remain;
@@ -205,7 +200,7 @@ static void distribution_handler(int nr)
* Test that all running threads _eventually_ receive CLOCK_PROCESS_CPUTIME_ID
* timer signals. This primarily tests that the kernel does not favour any one.
*/
-static int check_timer_distribution(void)
+static void check_timer_distribution(void)
{
const int nthreads = 10;
pthread_t threads[nthreads];
@@ -221,26 +216,20 @@ static int check_timer_distribution(void)
done = 0;
remain = nthreads + 1; /* worker threads + this thread */
- signal(SIGALRM, distribution_handler);
+ if (signal(SIGALRM, distribution_handler) == SIG_ERR)
+ fatal_error(NULL, "signal()");
+
err = timer_create(CLOCK_PROCESS_CPUTIME_ID, NULL, &id);
- if (err < 0) {
- ksft_perror("Can't create timer");
- return -1;
- }
+ if (err < 0)
+ fatal_error(NULL, "timer_create()");
+
err = timer_settime(id, 0, &val, NULL);
- if (err < 0) {
- ksft_perror("Can't set timer");
- return -1;
- }
+ if (err < 0)
+ fatal_error(NULL, "timer_settime()");
for (i = 0; i < nthreads; i++) {
- err = pthread_create(&threads[i], NULL, distribution_thread,
- NULL);
- if (err) {
- ksft_print_msg("Can't create thread: %s (%d)\n",
- strerror(errno), errno);
- return -1;
- }
+ if (pthread_create(&threads[i], NULL, distribution_thread, NULL))
+ fatal_error(NULL, "pthread_create()");
}
/* Wait for all threads to receive the signal. */
@@ -252,23 +241,15 @@ static int check_timer_distribution(void)
}
done = 1;
- if (timer_delete(id)) {
- ksft_perror("Can't delete timer\n");
- return -1;
- }
+ if (timer_delete(id))
+ fatal_error(NULL, "timer_delete()");
for (i = 0; i < nthreads; i++) {
- err = pthread_join(threads[i], NULL);
- if (err) {
- ksft_print_msg("Can't join thread: %s (%d)\n",
- strerror(errno), errno);
- return -1;
- }
+ if (pthread_join(threads[i], NULL))
+ fatal_error(NULL, "pthread_join()");
}
ksft_test_result((now - start <= 5), "%s\n", __func__);
-
- return 0;
}
int main(int argc, char **argv)
@@ -279,17 +260,10 @@ int main(int argc, char **argv)
ksft_print_msg("Testing posix timers. False negative may happen on CPU execution\n");
ksft_print_msg("based timers if other threads run on the CPU...\n");
- if (check_itimer(ITIMER_VIRTUAL) < 0)
- return ksft_exit_fail();
-
- if (check_itimer(ITIMER_PROF) < 0)
- return ksft_exit_fail();
-
- if (check_itimer(ITIMER_REAL) < 0)
- return ksft_exit_fail();
-
- if (check_timer_create(CLOCK_THREAD_CPUTIME_ID) < 0)
- return ksft_exit_fail();
+ check_itimer(ITIMER_VIRTUAL);
+ check_itimer(ITIMER_PROF);
+ check_itimer(ITIMER_REAL);
+ check_timer_create(CLOCK_THREAD_CPUTIME_ID);
/*
* It's unfortunately hard to reliably test a timer expiration
@@ -300,11 +274,8 @@ int main(int argc, char **argv)
* 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 ksft_exit_fail();
-
- if (check_timer_distribution() < 0)
- return ksft_exit_fail();
+ check_timer_create(CLOCK_PROCESS_CPUTIME_ID);
+ check_timer_distribution();
ksft_finished();
}
--
2.44.0.rc1.240.g4c46232300-goog
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH v1 3/3] selftests/timers/posix_timers: Use llabs for long long
2024-03-04 18:11 [PATCH v1 0/3] selftests/timers/posix_timers: various cleanups Edward Liaw
2024-03-04 18:11 ` [PATCH v1 1/3] selftests/timers/posix_timers: Make signal distribution test less fragile Edward Liaw
2024-03-04 18:11 ` [PATCH v1 2/3] selftests/timers/posix_timers: Use TAP reporting format Edward Liaw
@ 2024-03-04 18:11 ` Edward Liaw
2024-03-07 21:04 ` [PATCH v1 0/3] selftests/timers/posix_timers: various cleanups Thomas Gleixner
3 siblings, 0 replies; 6+ messages in thread
From: Edward Liaw @ 2024-03-04 18:11 UTC (permalink / raw
To: linux-kernel, John Stultz, Thomas Gleixner, Stephen Boyd,
Shuah Khan, Nathan Chancellor, Nick Desaulniers, Bill Wendling,
Justin Stitt
Cc: linux-kselftest, kernel-team, Edward Liaw, llvm
Fixes clang warning: absolute value function 'abs' given an argument of
type 'long long' but has parameter of type 'int' which may cause
truncation of value.
Signed-off-by: Edward Liaw <edliaw@google.com>
---
tools/testing/selftests/timers/posix_timers.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/timers/posix_timers.c b/tools/testing/selftests/timers/posix_timers.c
index 0f550fc9e879..78b4b2d3dc44 100644
--- a/tools/testing/selftests/timers/posix_timers.c
+++ b/tools/testing/selftests/timers/posix_timers.c
@@ -82,7 +82,7 @@ static int check_diff(struct timeval start, struct timeval end)
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)
+ if (llabs(diff - DELAY * USECS_PER_SEC) > USECS_PER_SEC / 2)
return -1;
return 0;
--
2.44.0.rc1.240.g4c46232300-goog
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH v1 0/3] selftests/timers/posix_timers: various cleanups
2024-03-04 18:11 [PATCH v1 0/3] selftests/timers/posix_timers: various cleanups Edward Liaw
` (2 preceding siblings ...)
2024-03-04 18:11 ` [PATCH v1 3/3] selftests/timers/posix_timers: Use llabs for long long Edward Liaw
@ 2024-03-07 21:04 ` Thomas Gleixner
[not found] ` <CAG4es9XXYzzrt3-eybtXZ2Cy9fTtEPiCbggDxPcaRY=fiKM78A@mail.gmail.com>
3 siblings, 1 reply; 6+ messages in thread
From: Thomas Gleixner @ 2024-03-07 21:04 UTC (permalink / raw
To: Edward Liaw, linux-kernel, John Stultz, Stephen Boyd, Shuah Khan,
Nathan Chancellor, Nick Desaulniers, Bill Wendling, Justin Stitt
Cc: linux-kselftest, kernel-team, Edward Liaw, llvm
On Mon, Mar 04 2024 at 18:11, Edward Liaw wrote:
> I'm sending some patches that were orignally in
> https://lore.kernel.org/lkml/20230606132949.068951363@linutronix.de/
> to prevent the timer_distribution test from hanging and also fix some
> format inconsistencies.
Thanks for picking those up and moving them forward. Any particular
reason why you didn't pick up the full set?
Thanks,
tglx
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v1 0/3] selftests/timers/posix_timers: various cleanups
[not found] ` <CAG4es9XXYzzrt3-eybtXZ2Cy9fTtEPiCbggDxPcaRY=fiKM78A@mail.gmail.com>
@ 2024-03-07 21:41 ` Thomas Gleixner
0 siblings, 0 replies; 6+ messages in thread
From: Thomas Gleixner @ 2024-03-07 21:41 UTC (permalink / raw
To: Edward Liaw
Cc: linux-kernel, John Stultz, Stephen Boyd, Shuah Khan,
Nathan Chancellor, Nick Desaulniers, Bill Wendling, Justin Stitt,
linux-kselftest, kernel-team, llvm
On Thu, Mar 07 2024 at 13:34, Edward Liaw wrote:
>> Thanks for picking those up and moving them forward. Any particular
>> reason why you didn't pick up the full set?
>
> I didn't know enough about the code to resolve some of the merges in the
> full set. I had run into the issue with the test timer_distribution test
> hanging on the Android kernel and wanted to get that fixed first.
Fair enough. I've marked your series for my post merge window tree and
I'll have a look at the rest of the pile.
Thanks,
tglx
^ permalink raw reply [flat|nested] 6+ messages in thread
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2024-03-07 21:04 ` [PATCH v1 0/3] selftests/timers/posix_timers: various cleanups Thomas Gleixner
[not found] ` <CAG4es9XXYzzrt3-eybtXZ2Cy9fTtEPiCbggDxPcaRY=fiKM78A@mail.gmail.com>
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