| Message ID | 20190610173829.4741-1-jean-philippe.brucker@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] firmware/psci: psci_checker: Park kthreads before stopping them | expand |
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
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 >
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
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);
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(-)