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From: John Baldwin <jhb@freebsd.org>
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Date: Fri, 26 Sep 2008 09:49:20 -0400
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Cc: Jeff Wheelhouse <freebsd-hackers@wheelhouse.org>,
	Dag-Erling =?utf-8?q?Sm=C3=B8rgrav?= <des@des.no>
Subject: Re: Major SMP problems with lstat/namei
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On Friday 26 September 2008 05:20:14 am Dag-Erling Sm=C3=B8rgrav wrote:
> Jeff Wheelhouse <freebsd-hackers@wheelhouse.org> writes:
> > http://software.wheelhouse.org/rptest.tar.bz2
>=20
> 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 se=
e=20
which locks (if any) are contested.

=2D-=20
John Baldwin