Re: [patch] sched: fix scheduling latencies for !PREEMPT kernels

William Lee Irwin III
2004-09-15T20:43:10Z

On Wed, Sep 15, 2004 at 06:36:24AM -0700, Hans Reiser wrote:
> Why bother? It is V3, it should be left undisturbed except for
> bugfixes. Please, spend your efforts on reducing V4 latency and
> measuring whether it fails to scale to multiple processors. That would
> be very useful to me if someone helped with that. V4 has the
> architecture for doing such things well, but there are always accidental
> bottlenecks that testing can discover, and I am sure we will have a
> handful of things preventing us from scaling well that are not hard to
> fix. It would be nice to fix those......
> The hard stuff for scalability, the locking of the tree, we did that.
> We just haven't tested and evaluated and refined like we need to in V4.

It's not for scalability; it's for cleaning up the users, which are
universally buggy. My suggestion above would not, in fact, make reiser3
any more scalable; it would merely isolate the locking semantics it
couldn't live without into its own internals.

-- wli