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Re: Name cache locking issue?



We should make it MI.

But why not just use an rwlock?

-- thorpej@iPhone

On Apr 11, 2008, at 4:59 PM, Andrew Doran <ad%netbsd.org@localhost> wrote:

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


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