Re: [PATCH] Yielding processor resources during lock contention

[Andrew Morton]

Zwane Mwaikambo <zwane@xxxxxxxxxxx> wrote:
>
> The following patch introduces cpu_lock_yield which allows architectures 
>  to possibly yield processor resources during lock contention.

err.. Haven't you just invented a really sucky semaphore?

> The original 
>  requirement stems from Paul's requirement on PPC64 LPAR systems to yield 
>  the processor to the hypervisor instead of spinning.

Maybe Paul needs to use a semaphore.


Now, maybe Paul has tied himself into sufficiently tangly locking knots
that in some circumstances he needs to spin on the lock and cannot schedule
away.  But he can still use a semaphore and spin on down_trylock.

Confused by all of this.
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