Re: Name cache locking issue?

[Andrew Doran <ad%netbsd.org@localhost>]

On Fri, Apr 11, 2008 at 04:21:17PM -0700, Jason Thorpe wrote:

> On Apr 11, 2008, at 8:25 AM, Andrew Doran wrote:
> >
> >Module Name: src
> >Committed By:        ad
> >Date:                Fri Apr 11 15:25:24 UTC 2008
> >
> >Modified Files:
> >     src/sys/kern: kern_cpu.c vfs_cache.c
> >     src/sys/sys: cpu_data.h namei.src
> >
> >Log Message:
> >Restructure the name cache code to eliminate most lock contention
> >resulting from forward lookups. Discussed on tech-kern@.
> 
> Hm, is cache_lock_cpus() safe if CPU_INFO_ITERATOR() happens to return  
> the CPUs in a different order on different CPUs?

A quick check shows that they all start from the same point (the first CPU)
so it should be OK. I guess we should document that somewhere, and maybe get
rid of the MD macro altogether.

Andrew