Hello, I am trying to figure out if Xenomai would work correctly with Lttng. Currently I haven’t figured out how the system manages buffers, but I am checking if this would be generally applicable to Xenomai.
I’d like to know if anyone has already used Lttng UST with xenomai threads, and if there is any need to compile lttng/liburcu for xenomai or using some patches. (I haven’t seen anything that indicates it would not work). ## urcu flavours This has a few variants, lttng uses the bulletproof one. Most others should be faster on average – but all of them might unlock a futex with a raw syscall. Other flavours like qsbr could likely be faster if the futex sycall would be replaced with a cobalt mutex (it’s very unlikely this path is executed). Would need some work to get this done (and lttng to use it). ## sys_membarrier recent kernels and liburcu versions support this syscall, which supposedly allows removal of reader memory barriers. The syscall will somehow interrupt the threads (all *running threads* of the process), which implicitly causes a barrier for readers. Q: I guess this will *not* interrupt xenomai threads, as their shadow linux thread is not *running*? Q: x86_64 accesses are strictly ordered, do you actually need membarriers at all? Kind regards, Norbert ________________________________ This message and any attachments are solely for the use of the intended recipients. They may contain privileged and/or confidential information or other information protected from disclosure. If you are not an intended recipient, you are hereby notified that you received this email in error and that any review, dissemination, distribution or copying of this email and any attachment is strictly prohibited. If you have received this email in error, please contact the sender and delete the message and any attachment from your system. ANDRITZ HYDRO GmbH Rechtsform/ Legal form: Gesellschaft mit beschränkter Haftung / Corporation Firmensitz/ Registered seat: Wien Firmenbuchgericht/ Court of registry: Handelsgericht Wien Firmenbuchnummer/ Company registration: FN 61833 g DVR: 0605077 UID-Nr.: ATU14756806 Thank You ________________________________
