Date: Fri, 13 Apr 2007 19:29:32 +0400 From: Sergey Zaharchenko <doublef-ctm@yandex.ru> To: Oliver Fromme <olli@lurza.secnetix.de> Cc: freebsd-current@FreeBSD.ORG Subject: Re: ZFS committed to the FreeBSD base. Message-ID: <20070413152932.GA3088@shark.localdomain> In-Reply-To: <200704131452.l3DEqjXv040099@lurza.secnetix.de> References: <freebsd-current.20070413164840.V31079@besplex.bde.org> <200704131452.l3DEqjXv040099@lurza.secnetix.de>
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--nFreZHaLTZJo0R7j Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable [cc list trimmed] Hello Oliver! Fri, Apr 13, 2007 at 04:52:45PM +0200 you wrote: > Using cmpxchg8b with a lock prefix wouldn't be a good idea > anyway. If I remember correctly, the lock cmpxchg8b > combination was the cause of the infamous "F00F" bug of > old Pentium processors. It causes them to freeze. AFAICT the bug only manifested itself when the instruction had an invalid register operand: www.intel.com/support/processors/pentium/ppiie/ : > It is illegal to use a register as the destination. ... If a > register is used as the destination, the processor normally stops > execution of the CMPXCH8B instruction, signals this error > condition and executes an error handler in software. > This erratum occurs if the CMPXCHG8B instruction is also locked ... > and an invalid register destination is used. So normal instructions should be OK. The fix was there to protect the system from malicious code which could hang it. --=20 DoubleF No virus detected in this message. Ehrm, wait a minute... /kernel: pid 56921 (antivirus), uid 32000: exited on signal 9 Oh yes, no virus:) --nFreZHaLTZJo0R7j Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.1 (FreeBSD) iD8DBQFGH6Hbwo7hT/9lVdwRAjQKAJ0W0wBuh1mU/qBi97+58em8ldPq3wCfY1Pl 6T7FanHOlPTZ7DQThpp9foU= =SN/w -----END PGP SIGNATURE----- --nFreZHaLTZJo0R7j--
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