[Xenomai-core] Overcoming the foreign stack

2010-10-05 Thread Jan Kiszka
Hi, quite a few limitations and complications of using Linux services over non-Linux domains relate to potentially invalid current and thread_info. The non-Linux domain could maintain their own kernel stacks while Linux tend to derive current and thread_info from the stack pointer. This is not an

Re: [Xenomai-core] Overcoming the foreign stack

2010-10-05 Thread Gilles Chanteperdrix
Jan Kiszka wrote: Hi, quite a few limitations and complications of using Linux services over non-Linux domains relate to potentially invalid current and thread_info. The non-Linux domain could maintain their own kernel stacks while Linux tend to derive current and thread_info from the stack

Re: [Xenomai-core] Overcoming the foreign stack

2010-10-05 Thread Jan Kiszka
Am 05.10.2010 11:56, Gilles Chanteperdrix wrote: Jan Kiszka wrote: Hi, quite a few limitations and complications of using Linux services over non-Linux domains relate to potentially invalid current and thread_info. The non-Linux domain could maintain their own kernel stacks while Linux tend

Re: [Xenomai-core] Overcoming the foreign stack

2010-10-05 Thread Gilles Chanteperdrix
Jan Kiszka wrote: - consistent view on the system (if current is always valid, there are no more confusions between current Linux vs. Xenomai task) That is inherently incompatible with the co-kernel approach. Xenomai will always be able to preempt Linux at a place where the state is not

Re: [Xenomai-core] Overcoming the foreign stack

2010-10-05 Thread Jan Kiszka
Am 05.10.2010 12:32, Gilles Chanteperdrix wrote: Jan Kiszka wrote: - consistent view on the system (if current is always valid, there are no more confusions between current Linux vs. Xenomai task) That is inherently incompatible with the co-kernel approach. Xenomai will always be able

Re: [Xenomai-core] Overcoming the foreign stack

2010-10-05 Thread Gilles Chanteperdrix
Jan Kiszka wrote: Am 05.10.2010 12:32, Gilles Chanteperdrix wrote: Jan Kiszka wrote: - consistent view on the system (if current is always valid, there are no more confusions between current Linux vs. Xenomai task) That is inherently incompatible with the co-kernel approach. Xenomai will

Re: [Xenomai-core] Overcoming the foreign stack

2010-10-05 Thread Gilles Chanteperdrix
Jan Kiszka wrote: My key question is currently if and how much of this could be realized in 2.6. Could we drop in-kernel skins in that version? If not, what about disabling them by default, converting RTDM tasks to a kthread-based approach, and enabling tracing etc. only in that case?

Re: [Xenomai-core] Overcoming the foreign stack

2010-10-05 Thread Jan Kiszka
Am 05.10.2010 12:59, Gilles Chanteperdrix wrote: Jan Kiszka wrote: My key question is currently if and how much of this could be realized in 2.6. Could we drop in-kernel skins in that version? If not, what about disabling them by default, converting RTDM tasks to a kthread-based approach, and

Re: [Xenomai-core] Overcoming the foreign stack

2010-10-05 Thread Jan Kiszka
Am 05.10.2010 13:06, Jan Kiszka wrote: Am 05.10.2010 12:59, Gilles Chanteperdrix wrote: Jan Kiszka wrote: My key question is currently if and how much of this could be realized in 2.6. Could we drop in-kernel skins in that version? If not, what about disabling them by default, converting RTDM

Re: [Xenomai-core] Overcoming the foreign stack

2010-10-05 Thread Gilles Chanteperdrix
Jan Kiszka wrote: Hi, quite a few limitations and complications of using Linux services over non-Linux domains relate to potentially invalid current and thread_info. The non-Linux domain could maintain their own kernel stacks while Linux tend to derive current and thread_info from the stack

Re: [Xenomai-core] Overcoming the foreign stack

2010-10-05 Thread Jan Kiszka
Am 05.10.2010 15:15, Gilles Chanteperdrix wrote: Jan Kiszka wrote: Hi, quite a few limitations and complications of using Linux services over non-Linux domains relate to potentially invalid current and thread_info. The non-Linux domain could maintain their own kernel stacks while Linux tend

Re: [Xenomai-core] Overcoming the foreign stack

2010-10-05 Thread Gilles Chanteperdrix
Jan Kiszka wrote: Am 05.10.2010 15:15, Gilles Chanteperdrix wrote: Jan Kiszka wrote: Hi, quite a few limitations and complications of using Linux services over non-Linux domains relate to potentially invalid current and thread_info. The non-Linux domain could maintain their own kernel

Re: [Xenomai-core] Overcoming the foreign stack

2010-10-05 Thread Jan Kiszka
Am 05.10.2010 15:42, Gilles Chanteperdrix wrote: Jan Kiszka wrote: Am 05.10.2010 15:15, Gilles Chanteperdrix wrote: Jan Kiszka wrote: Hi, quite a few limitations and complications of using Linux services over non-Linux domains relate to potentially invalid current and thread_info. The

Re: [Xenomai-core] Overcoming the foreign stack

2010-10-05 Thread Gilles Chanteperdrix
Jan Kiszka wrote: Am 05.10.2010 15:42, Gilles Chanteperdrix wrote: Jan Kiszka wrote: Am 05.10.2010 15:15, Gilles Chanteperdrix wrote: Jan Kiszka wrote: Hi, quite a few limitations and complications of using Linux services over non-Linux domains relate to potentially invalid current and

Re: [Xenomai-core] Overcoming the foreign stack

2010-10-05 Thread Jan Kiszka
Am 05.10.2010 15:50, Gilles Chanteperdrix wrote: Jan Kiszka wrote: Am 05.10.2010 15:42, Gilles Chanteperdrix wrote: Jan Kiszka wrote: Am 05.10.2010 15:15, Gilles Chanteperdrix wrote: Jan Kiszka wrote: Hi, quite a few limitations and complications of using Linux services over non-Linux

Re: [Xenomai-core] Overcoming the foreign stack

2010-10-05 Thread Gilles Chanteperdrix
Jan Kiszka wrote: Am 05.10.2010 15:50, Gilles Chanteperdrix wrote: Jan Kiszka wrote: Am 05.10.2010 15:42, Gilles Chanteperdrix wrote: Jan Kiszka wrote: Am 05.10.2010 15:15, Gilles Chanteperdrix wrote: Jan Kiszka wrote: Hi, quite a few limitations and complications of using Linux services