Date: Thu, 30 Mar 2000 10:05:26 -0800 From: Mike Smith <msmith@freebsd.org> To: Poul-Henning Kamp <phk@critter.freebsd.dk> Cc: Bruce Evans <bde@zeta.org.au>, Mike Smith <msmith@freebsd.org>, Matthew Dillon <dillon@apollo.backplane.com>, freebsd-current@freebsd.org Subject: Re: SMP buildworld times / performance tests Message-ID: <200003301805.KAA00452@mass.cdrom.com> In-Reply-To: Your message of "Thu, 30 Mar 2000 13:37:32 %2B0200." <1274.954416252@critter.freebsd.dk>
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> >> Just following on from this, one thing that I can see immediately being > >> very important to me at least is a spinlock in the timecounter structure. > >> Calcru and various other things call microtime(), and we're going to want > >> to lock out updates and parallel accesses to the timecounter. What > >> should we be using for an interrupt-disabling spinlock? > > > >Nothing. Accesses to the timecounter struct are already MP safe and fast. > >Only the i8254 timecounter hardware currently needs interrupt-disabling, > >but it is hopefully never used on SMP machines. > > Worse. It is used by default on SMP machines which don't sport the > PIIX timecounter. ie. anything using the PIIX3 or older (think 440FX dual P6 systems, etc.) -- \\ Give a man a fish, and you feed him for a day. \\ Mike Smith \\ Tell him he should learn how to fish himself, \\ msmith@freebsd.org \\ and he'll hate you for a lifetime. \\ msmith@cdrom.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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