Re: [PATCH] 2.4.0-prerelease: preemptive kernel.

[Nigel Gamble]

On Thu, 4 Jan 2001, Andi Kleen wrote:
> The problem is that current Linux semaphores are very costly locks -- they
> always cause a context switch.

My preemptible kernel patch currently just uses Linux semaphores to
implement sleeping kernel mutexes, but we (at MontaVista Software) are
working on a new implementation that also does priority inheritance,
to avoid the priority inversion problem, and that does the minimum
necessary context switches.

Nigel Gamble                                    [e-mail]
Mountain View, CA, USA.                         http://www.nrg.org/