* [PATCH v2] firmware/psci: psci_checker: Park kthreads before stopping them
@ 2019-06-10 17:38 Jean-Philippe Brucker
2019-06-11 9:42 ` Sudeep Holla
2019-06-11 10:48 ` Lorenzo Pieralisi
0 siblings, 2 replies; 4+ messages in thread
From: Jean-Philippe Brucker @ 2019-06-10 17:38 UTC (permalink / raw)
To: lorenzo.pieralisi; +Cc: mark.rutland, linux-arm-kernel, sudeep.holla
Since commit 85f1abe0019f ("kthread, sched/wait: Fix kthread_parkme()
completion issue"), kthreads that are bound to a CPU must be parked
before being stopped. At the moment the PSCI checker calls
kthread_stop() directly on the suspend kthread, which triggers the
following warning:
[ 6.068288] WARNING: CPU: 1 PID: 1 at kernel/kthread.c:398 __kthread_bind_mask+0x20/0x78
...
[ 6.190151] Call trace:
[ 6.192566] __kthread_bind_mask+0x20/0x78
[ 6.196615] kthread_unpark+0x74/0x80
[ 6.200235] kthread_stop+0x44/0x1d8
[ 6.203769] psci_checker+0x3bc/0x484
[ 6.207389] do_one_initcall+0x48/0x260
[ 6.211180] kernel_init_freeable+0x2c8/0x368
[ 6.215488] kernel_init+0x10/0x100
[ 6.218935] ret_from_fork+0x10/0x1c
[ 6.222467] ---[ end trace e05e22863d043cd3 ]---
kthread_unpark() tries to bind the thread to its CPU and aborts with a
WARN() if the thread wasn't in TASK_PARKED state. Park the kthreads
before stopping them.
Fixes: 85f1abe0019f ("kthread, sched/wait: Fix kthread_parkme() completion issue")
Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
---
Since v1: rebased onto v5.2-rc4
---
drivers/firmware/psci/psci_checker.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/drivers/firmware/psci/psci_checker.c b/drivers/firmware/psci/psci_checker.c
index 08c85099d4d0..f3659443f8c2 100644
--- a/drivers/firmware/psci/psci_checker.c
+++ b/drivers/firmware/psci/psci_checker.c
@@ -359,16 +359,16 @@ static int suspend_test_thread(void *arg)
for (;;) {
/* Needs to be set first to avoid missing a wakeup. */
set_current_state(TASK_INTERRUPTIBLE);
- if (kthread_should_stop()) {
- __set_current_state(TASK_RUNNING);
+ if (kthread_should_park())
break;
- }
schedule();
}
pr_info("CPU %d suspend test results: success %d, shallow states %d, errors %d\n",
cpu, nb_suspend, nb_shallow_sleep, nb_err);
+ kthread_parkme();
+
return nb_err;
}
@@ -433,8 +433,10 @@ static int suspend_tests(void)
/* Stop and destroy all threads, get return status. */
- for (i = 0; i < nb_threads; ++i)
+ for (i = 0; i < nb_threads; ++i) {
+ err += kthread_park(threads[i]);
err += kthread_stop(threads[i]);
+ }
out:
cpuidle_resume_and_unlock();
kfree(threads);
--
2.21.0
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^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH v2] firmware/psci: psci_checker: Park kthreads before stopping them
2019-06-10 17:38 [PATCH v2] firmware/psci: psci_checker: Park kthreads before stopping them Jean-Philippe Brucker
@ 2019-06-11 9:42 ` Sudeep Holla
2019-06-11 10:48 ` Lorenzo Pieralisi
1 sibling, 0 replies; 4+ messages in thread
From: Sudeep Holla @ 2019-06-11 9:42 UTC (permalink / raw)
To: Jean-Philippe Brucker
Cc: mark.rutland, lorenzo.pieralisi, linux-arm-kernel, Sudeep Holla
On Mon, Jun 10, 2019 at 06:38:29PM +0100, Jean-Philippe Brucker wrote:
> Since commit 85f1abe0019f ("kthread, sched/wait: Fix kthread_parkme()
> completion issue"), kthreads that are bound to a CPU must be parked
> before being stopped. At the moment the PSCI checker calls
> kthread_stop() directly on the suspend kthread, which triggers the
> following warning:
>
> [ 6.068288] WARNING: CPU: 1 PID: 1 at kernel/kthread.c:398 __kthread_bind_mask+0x20/0x78
> ...
> [ 6.190151] Call trace:
> [ 6.192566] __kthread_bind_mask+0x20/0x78
> [ 6.196615] kthread_unpark+0x74/0x80
> [ 6.200235] kthread_stop+0x44/0x1d8
> [ 6.203769] psci_checker+0x3bc/0x484
> [ 6.207389] do_one_initcall+0x48/0x260
> [ 6.211180] kernel_init_freeable+0x2c8/0x368
> [ 6.215488] kernel_init+0x10/0x100
> [ 6.218935] ret_from_fork+0x10/0x1c
> [ 6.222467] ---[ end trace e05e22863d043cd3 ]---
>
> kthread_unpark() tries to bind the thread to its CPU and aborts with a
> WARN() if the thread wasn't in TASK_PARKED state. Park the kthreads
> before stopping them.
>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
--
Regards,
Sudeep
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^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH v2] firmware/psci: psci_checker: Park kthreads before stopping them
2019-06-10 17:38 [PATCH v2] firmware/psci: psci_checker: Park kthreads before stopping them Jean-Philippe Brucker
2019-06-11 9:42 ` Sudeep Holla
@ 2019-06-11 10:48 ` Lorenzo Pieralisi
2019-06-17 11:51 ` Olof Johansson
1 sibling, 1 reply; 4+ messages in thread
From: Lorenzo Pieralisi @ 2019-06-11 10:48 UTC (permalink / raw)
To: Jean-Philippe Brucker, arm, arnd, olof
Cc: mark.rutland, linux-arm-kernel, sudeep.holla
Hi Arnd, Olof,
Can you pick this up please (with my ACK below) or you prefer me
resending it ?
On Mon, Jun 10, 2019 at 06:38:29PM +0100, Jean-Philippe Brucker wrote:
> Since commit 85f1abe0019f ("kthread, sched/wait: Fix kthread_parkme()
> completion issue"), kthreads that are bound to a CPU must be parked
> before being stopped. At the moment the PSCI checker calls
> kthread_stop() directly on the suspend kthread, which triggers the
> following warning:
>
> [ 6.068288] WARNING: CPU: 1 PID: 1 at kernel/kthread.c:398 __kthread_bind_mask+0x20/0x78
> ...
> [ 6.190151] Call trace:
> [ 6.192566] __kthread_bind_mask+0x20/0x78
> [ 6.196615] kthread_unpark+0x74/0x80
> [ 6.200235] kthread_stop+0x44/0x1d8
> [ 6.203769] psci_checker+0x3bc/0x484
> [ 6.207389] do_one_initcall+0x48/0x260
> [ 6.211180] kernel_init_freeable+0x2c8/0x368
> [ 6.215488] kernel_init+0x10/0x100
> [ 6.218935] ret_from_fork+0x10/0x1c
> [ 6.222467] ---[ end trace e05e22863d043cd3 ]---
>
> kthread_unpark() tries to bind the thread to its CPU and aborts with a
> WARN() if the thread wasn't in TASK_PARKED state. Park the kthreads
> before stopping them.
>
> Fixes: 85f1abe0019f ("kthread, sched/wait: Fix kthread_parkme() completion issue")
> Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
> ---
> Since v1: rebased onto v5.2-rc4
> ---
> drivers/firmware/psci/psci_checker.c | 10 ++++++----
> 1 file changed, 6 insertions(+), 4 deletions(-)
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> diff --git a/drivers/firmware/psci/psci_checker.c b/drivers/firmware/psci/psci_checker.c
> index 08c85099d4d0..f3659443f8c2 100644
> --- a/drivers/firmware/psci/psci_checker.c
> +++ b/drivers/firmware/psci/psci_checker.c
> @@ -359,16 +359,16 @@ static int suspend_test_thread(void *arg)
> for (;;) {
> /* Needs to be set first to avoid missing a wakeup. */
> set_current_state(TASK_INTERRUPTIBLE);
> - if (kthread_should_stop()) {
> - __set_current_state(TASK_RUNNING);
> + if (kthread_should_park())
> break;
> - }
> schedule();
> }
>
> pr_info("CPU %d suspend test results: success %d, shallow states %d, errors %d\n",
> cpu, nb_suspend, nb_shallow_sleep, nb_err);
>
> + kthread_parkme();
> +
> return nb_err;
> }
>
> @@ -433,8 +433,10 @@ static int suspend_tests(void)
>
>
> /* Stop and destroy all threads, get return status. */
> - for (i = 0; i < nb_threads; ++i)
> + for (i = 0; i < nb_threads; ++i) {
> + err += kthread_park(threads[i]);
> err += kthread_stop(threads[i]);
> + }
> out:
> cpuidle_resume_and_unlock();
> kfree(threads);
> --
> 2.21.0
>
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^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH v2] firmware/psci: psci_checker: Park kthreads before stopping them
2019-06-11 10:48 ` Lorenzo Pieralisi
@ 2019-06-17 11:51 ` Olof Johansson
0 siblings, 0 replies; 4+ messages in thread
From: Olof Johansson @ 2019-06-17 11:51 UTC (permalink / raw)
To: Lorenzo Pieralisi
Cc: mark.rutland, arnd, Jean-Philippe Brucker, arm, sudeep.holla,
linux-arm-kernel
On Tue, Jun 11, 2019 at 11:48:23AM +0100, Lorenzo Pieralisi wrote:
> Hi Arnd, Olof,
>
> Can you pick this up please (with my ACK below) or you prefer me
> resending it ?
Resending is always slightly less work for us to collect acks, but I've applied
it at our end now.
Thanks!
-Olof
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^ permalink raw reply [flat|nested] 4+ messages in thread
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2019-06-10 17:38 [PATCH v2] firmware/psci: psci_checker: Park kthreads before stopping them Jean-Philippe Brucker
2019-06-11 9:42 ` Sudeep Holla
2019-06-11 10:48 ` Lorenzo Pieralisi
2019-06-17 11:51 ` Olof Johansson
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