Re: [patch] Real-Time Preemption, -RT-2.6.9-rc4-mm1-U8

[john cooper]

Scott Wood wrote:

> On Thu, Oct 21, 2004 at 06:15:00PM -0400, john cooper wrote:
>
> > Yes, but my concern was having to backoff in out-of-sequence
> > spinlock acquisition paths. 
>
> Out-of-sequence acquisition is a bug, unless the caller uses trylocks
> and handles backoff itself.
Understood -- we may be getting hung up on terminology here.

Rather the issue was whether the nondeterministic out-of-sequence
backoff could be pushed to a noncritical path. I believe so.
It is further likely a backoff would not be needed as the
a path acquiring a mutex's task-owned list lock during a
priority promotion scan shouldn't have reason to acquire any
task's mutex-owned list lock. The latter list would only need
to be locked at time of successful mutex acquisition/free.

-john

--
john.cooper@xxxxxxxxxxx

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