Re: sched_yield() makes OpenLDAP slow

[Nikita Danilov <nikita@clusterfs.com>]

Howard Chu <hyc@symas.com> writes:

[...]

> concurrency. It is the nature of such a system to encounter deadlocks
> over the normal course of operations. When a deadlock is detected, some
> thread must be chosen (by one of a variety of algorithms) to abort its
> transaction, in order to allow other operations to proceed to
> completion. In this situation, the chosen thread must get control of the
> CPU long enough to clean itself up,

What prevents transaction monitor from using, say, condition variables
to "yield cpu"? That would have an additional advantage of blocking
thread precisely until specific event occurs, instead of blocking for
some vague indeterminate load and platform dependent amount of time.

>                                     and then it must yield the CPU in
> order to allow any other competing threads to complete their
> transaction.

Again, this sounds like thing doable with standard POSIX synchronization
primitives.

>
> -- 
>   -- Howard Chu

Nikita.