On 25.01.22 09:25, Zhang, Qiang1 wrote:
On 19.01.22 14:31, Zqiang wrote:
The Xenomai does not yet support the concept of namespaces, and the
same task has different pids in its own pid namespace and parent pid
namespace. however, when the task running in a child pid namespace, we
only recorded the relationship between thread and child pid. so can't
use other pid to find thread.
To fix it, when the thread is created, record all pid in different
namespaces.
Updates: https://gitlab.com/Xenomai/xenomai-hacker-space/-/issues/19
Can you help refreshing my memory on that and also explain why it takes a
different approach than in [1]? That was reported to not work completely
either, yes, but the RCU limitation is now gone with everything switched to
Dovetail.
Hi Jan
This change doesn't depend on RCU, it apply to I-pipe and dovetail.
When switched to Dovetail, the RCU limitation is gone?
Dovetail allows to use RCU-protected read accesses from the out-of-band
(RT) stage, at least in 5.15:
https://source.denx.de/Xenomai/linux-dovetail/-/commit/49cad34e9c2d977a8069278393de922d40ec5d57
Looking at 5.10, there might be remaining restrictions, though possibly
resolvable by backporting the above:
https://source.denx.de/Xenomai/linux-dovetail/-/commit/f989126cca9a305a101e6ddf60a60ef062d1e7f4
As current master has dropped I-pipe support and this patch will likely
not be a backport candiate anyway, we may exploit this property and may
make the pid namespace solution simpler this way.
Jan
--
Siemens AG, Technology
Competence Center Embedded Linux
