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Priority Inheritance?

Posted Jul 19, 2006 22:41 UTC (Wed) by Felix_the_Mac (guest, #32242)
Parent article: Kernel Summit 2006: Realtime

I was under the impresion that the RT patchset included priority inheritance in the kernel. I know that Ingo has submitted patches for user space priority inheritance (which I think have been merged).

If RT is merged totally does it mean that the kernel will need to support kernel priority inheritance? Isn't this what Linus had been dead set against?

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Posted Jul 19, 2006 23:30 UTC (Wed) by corbet (editor, #1) [Link]

Priority inheritance is in 2.6.18. See this article for a description of the PI patch. There's not really any difference between user-space and kernel-space PI - it's all implemented in the kernel in any case.

Priority Inheritance?

Posted Jul 20, 2006 0:09 UTC (Thu) by mingo (subscriber, #31122) [Link]

yes. The kernel/rtmutex.c code which implements user-space PI (the new PI-futexes API) is the exact same code used for preemptible spinlocks too in -rt. It was not entirely trivial to merge the two uses into the same subsystem, but it's reality now. (And i dont want to take all credit for it, large portions of this solution were designed and written by Thomas Gleixner, Esben Nielsen and Steven Rostedt.)