Date: Thu, 30 Mar 2000 13:37:32 +0200 From: Poul-Henning Kamp <phk@critter.freebsd.dk> To: Bruce Evans <bde@zeta.org.au> Cc: Mike Smith <msmith@FreeBSD.ORG>, Matthew Dillon <dillon@apollo.backplane.com>, freebsd-current@FreeBSD.ORG Subject: Re: SMP buildworld times / performance tests Message-ID: <1274.954416252@critter.freebsd.dk> In-Reply-To: Your message of "Thu, 30 Mar 2000 21:24:28 %2B1000." <Pine.BSF.4.21.0003302111410.3247-100000@alphplex.bde.org>
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In message <Pine.BSF.4.21.0003302111410.3247-100000@alphplex.bde.org>, Bruce Ev ans writes: >On Wed, 29 Mar 2000, Mike Smith wrote: > >> 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. -- Poul-Henning Kamp FreeBSD coreteam member phk@FreeBSD.ORG "Real hackers run -current on their laptop." FreeBSD -- It will take a long time before progress goes too far! To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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