Gilles Chanteperdrix wrote:
> Jan Kiszka wrote:
>> Gilles Chanteperdrix wrote:
>>> Jan Kiszka wrote:
>>>> As the xnsched structures get initialized later, during xnpod_init,
>>>> xnsched_cpu always returned 0 in the gatekeeper_thread prologue. That
>>>> caused binding of all gatekeepers to CPU 0.
>>>>
>>>> Signed-off-by: Jan Kiszka <jan.kis...@siemens.com>
>>>> ---
>>>>
>>>> ksrc/nucleus/shadow.c | 5 ++++-
>>>> 1 files changed, 4 insertions(+), 1 deletions(-)
>>>>
>>>> diff --git a/ksrc/nucleus/shadow.c b/ksrc/nucleus/shadow.c
>>>> index 1dedd85..2243c0e 100644
>>>> --- a/ksrc/nucleus/shadow.c
>>>> +++ b/ksrc/nucleus/shadow.c
>>>> @@ -823,11 +823,14 @@ static int gatekeeper_thread(void *data)
>>>> struct task_struct *this_task = current;
>>>> DECLARE_WAITQUEUE(wait, this_task);
>>>> struct xnsched *sched = data;
>>>> - int cpu = xnsched_cpu(sched);
>>>> struct xnthread *target;
>>>> cpumask_t cpumask;
>>>> + int cpu;
>>>> spl_t s;
>>>>
>>>> + /* sched not fully initialized, xnsched_cpu does not work yet */
>>>> + cpu = sched - nkpod_struct.sched;
>>>> +
>>>> this_task->flags |= PF_NOFREEZE;
>>>> sigfillset(&this_task->blocked);
>>>> cpumask = cpumask_of_cpu(cpu);
>>> This does not look good, it means that the gatekeeper accesses the sched
>>> structure before it is initialized. So, IMO, the proper fix would be to
>>> start the gatekeepers only after the sched structure has been initialized.
>>>
>> I briefly thought about moving xnshadow_mount into xnpod_init. But given
>> the fact that it worked like this before and that I was not able to
>> quickly exclude new regressions when reordering things, I decided to
>> restore the old pattern.
>
> Ok. What about passing cpu as the gatekeeper argument, and using
> xnpod_sched_slot(cpu) to find the sched pointer ?
>
Something like this? Same result, but looks indeed a bit nicer.
----------->
As the xnsched structures get initialized later, during xnpod_init,
xnsched_cpu always returned 0 in the gatekeeper_thread prologue. That
caused binding of all gatekeepers to CPU 0.
Signed-off-by: Jan Kiszka <jan.kis...@siemens.com>
---
ksrc/nucleus/shadow.c | 8 ++++----
1 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/ksrc/nucleus/shadow.c b/ksrc/nucleus/shadow.c
index 1dedd85..6822fcb 100644
--- a/ksrc/nucleus/shadow.c
+++ b/ksrc/nucleus/shadow.c
@@ -822,8 +822,8 @@ static int gatekeeper_thread(void *data)
{
struct task_struct *this_task = current;
DECLARE_WAITQUEUE(wait, this_task);
- struct xnsched *sched = data;
- int cpu = xnsched_cpu(sched);
+ int cpu = (long)data;
+ struct xnsched *sched = xnpod_sched_slot(cpu);
struct xnthread *target;
cpumask_t cpumask;
spl_t s;
@@ -2600,8 +2600,8 @@ int xnshadow_mount(void)
sema_init(&sched->gksync, 0);
xnarch_memory_barrier();
sched->gatekeeper =
- kthread_create(&gatekeeper_thread, sched, "gatekeeper/%d",
- cpu);
+ kthread_create(&gatekeeper_thread, (void *)(long)cpu,
+ "gatekeeper/%d", cpu);
wake_up_process(sched->gatekeeper);
down(&sched->gksync);
}
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