Date: Tue, 20 Jun 2006 16:10:54 +0300 From: Andriy Gapon <avg@icyb.net.ua> To: John Baldwin <jhb@freebsd.org> Cc: freebsd-current@freebsd.org, Nate Lawson <nate@root.org> Subject: Re: Freeze due to performance_cx_lowest=LOW Message-ID: <4497F3DE.7030000@icyb.net.ua> In-Reply-To: <200606161509.28998.jhb@freebsd.org> References: <1148837064.00534930.1148826605@10.7.7.3> <200606011504.31635.jhb@freebsd.org> <44929864.4080207@icyb.net.ua> <200606161509.28998.jhb@freebsd.org>
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on 16/06/2006 22:09 John Baldwin said the following: > On Friday 16 June 2006 07:39, Andriy Gapon wrote: >> Maybe I will say something too ignorant for this list, but is it >> possible to drive hardclock with two interrupts (I haven't thought yet >> how, though) and use RTC as the second interrupt source ? >> I think that RTC/IRQ8 (usually) doesn't have problems associated with >> 8254 timer/IRQ0 and can be used without mixed mode. > > Well, you could use the RTC instead of the lapic timer on CPU 0 and then use > IPIs to forward clock interrupts to all the other CPUs just as we did before > we used the lapic timer. > Well, I think MP systems are "meant" to use lapic timer; anyway, I do not care much for them now :-) But I am exploring possibilities to avoid using lapic timer (or to augment it) on UP systems. And, as you confirm, RTC seems to be a good candidate for that. -- Andriy Gapon
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