Date: Tue, 6 Jul 2004 01:08:42 -0700 From: Kris Kennaway <kris@obsecurity.org> To: Tim Robbins <tjr@freebsd.org> Cc: ngl <ngl@ur.ru> Subject: Re: Shared/exclusive (rw) locks Message-ID: <20040706080842.GA23037@xor.obsecurity.org> In-Reply-To: <20040706071732.GA64106@cat.robbins.dropbear.id.au> References: <0e0401c46312$089eea10$8501a8c0@spirit> <20040706050055.GA63647@cat.robbins.dropbear.id.au> <0e3d01c46316$df50c7a0$8501a8c0@spirit> <20040706054134.GB63647@cat.robbins.dropbear.id.au> <0e6601c46324$d335afe0$8501a8c0@spirit> <20040706071732.GA64106@cat.robbins.dropbear.id.au>
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--AqsLC8rIMeq19msA Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Jul 06, 2004 at 05:17:32PM +1000, Tim Robbins wrote: > On Tue, Jul 06, 2004 at 12:45:27PM +0600, ngl wrote: > > That means, freebsd stable has no spin rwlocks ? >=20 > Right. Reader-writer spinlocks would not be very useful in FreeBSD 4; bec= ause > only one thread can be running in the kernel at once, the only opportunity > you'd have to share reader locks would be if you slept while holding a > spinlock, which is a bad idea (and not permitted by FreeBSD 5 or Linux). > If you want -rwlocks, you'll have to use lockmgr() (which is a sleep lock= ). i.e. perhaps you really want to be using FreeBSD 5. Kris --AqsLC8rIMeq19msA Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.4 (FreeBSD) iD8DBQFA6l4KWry0BWjoQKURAu41AKDz1jggNG5kIM8d1PaL7vKA79LWfwCePS2Y 77GjTjFvHE2AZ6EwomEtAeI= =glL0 -----END PGP SIGNATURE----- --AqsLC8rIMeq19msA--
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