Major SMP problems with lstat/namei

[John Baldwin]

On Friday 26 September 2008 05:20:14 am Dag-Erling Smørgrav wrote:
> Jeff Wheelhouse <freebsd-hackers at wheelhouse.org> writes:
> > http://software.wheelhouse.org/rptest.tar.bz2
> 
> Thanks.  I get similar results on head; vfs.lookup_shared actually seems
> to *reduce* performance by about 10% - 20%.  I ran the test on both UFS
> and ZFS; there is no significant difference.

You might try http://www.FreeBSD.org/~jhb/patches/namei_rwlock.patch

However, it might also be useful in general to enable lock profiling and see 
which locks (if any) are contested.

-- 
John Baldwin