Re: patent on O_ATOMICLOOKUP [Re: [PATCH] loopable tmpfs (2.4.17)]

Karim Yaghmour
2002-05-25T19:16:45Z

Linus Torvalds wrote:
> "..every single spinlock in the kernel assumes that the kernel isn't
> preempted, which means that user apps that can preempt the kernel
> cannot use them."

I misread this paragraph, the rest of my reply follows from this laps.

I said there was no "priority inversion" in the sense that there are
no priority inversion problems during the execution of such user-space
rt tasks. From a purely static perspective, however, the user-space
rt tasks do indeed come to have a higher priority than the kernel.
No fuss there.

That being said, I differ on your judgement of this method.

Karim

===================================================
Karim Yaghmour
karim@opersys.com
Embedded and Real-Time Linux Expert
===================================================