[Lustre-devel] SMP Scalability, MDS, reducing cpu pingpong

[Ricardo M. Correia]

On Qua, 2009-07-29 at 12:01 -0400, Oleg Drokin wrote:
> Yes. If clients are not contending, we have same benefits, but
> this never happens in the real world.
> Creates in a same dir is a contention point on the dir and there is
> no point in scheduling all clients on different cpus and let them
> serialize, where we can free those cpus for some other set of clients
> doing something else.

Will this still be true with the DMU?

I don't know which locks are involved at the Lustre level, but the DMU
itself does leaf-level locking of ZAP structures (used for directories).

Cheers,
Ricardo