Hi Rouven, On Wed, Jul 3, 2019 at 12:04 PM Rouven Czerwinski <[email protected]> wrote: > > If the kernel is compiled with CONFIG_PREEMPT_VOLUNTARY and OP-TEE is > executing a long running workload, the following errors are raised: > > [ 1705.971228] rcu: INFO: rcu_sched detected stalls on CPUs/tasks: > [ 1705.977195] rcu: (detected by 0, t=2102 jiffies, g=51977, q=3) > [ 1705.983152] rcu: All QSes seen, last rcu_sched kthread activity 2102 > (140596-138494), jiffies_till_next_fqs=1, root ->qsmask 0x0 > [ 1705.994729] optee-xtest R running task 0 169 157 > 0x00000002 > > While OP-TEE is returning regulary to the kernel due to timer > interrrupts, the OPTEE_SMC_FUNC_FOREIGN_INTR case does not contain an > explicit rescheduling point. Add a might_sleep() to the RPC request case > to ensure that the kernel can reschedule another task if OP-TEE requests > RPC handling. > > Signed-off-by: Rouven Czerwinski <[email protected]> > --- > drivers/tee/optee/call.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/tee/optee/call.c b/drivers/tee/optee/call.c > index aa942703ae65..13b0269a0abc 100644 > --- a/drivers/tee/optee/call.c > +++ b/drivers/tee/optee/call.c > @@ -148,6 +148,7 @@ u32 optee_do_call_with_arg(struct tee_context *ctx, > phys_addr_t parg) > */ > optee_cq_wait_for_completion(&optee->call_queue, &w); > } else if (OPTEE_SMC_RETURN_IS_RPC(res.a0)) { > + might_sleep(); > param.a0 = res.a0; > param.a1 = res.a1; > param.a2 = res.a2; > -- > 2.20.1 >
Looks good. I'll pick this up and fix the spell errors in the commit message. Thanks, Jens
