Skip site navigation (1)Skip section navigation (2)
Date:      Tue, 20 Jun 2006 20:15:39 +0300
From:      Andriy Gapon <avg@icyb.net.ua>
To:        freebsd-current@freebsd.org
Cc:        Nate Lawson <nate@root.org>
Subject:   Re: Freeze due to performance_cx_lowest=LOW
Message-ID:  <44982D3B.9050409@icyb.net.ua>
In-Reply-To: <4497F3DE.7030000@icyb.net.ua>
References:  <1148837064.00534930.1148826605@10.7.7.3> <200606011504.31635.jhb@freebsd.org> <44929864.4080207@icyb.net.ua> <200606161509.28998.jhb@freebsd.org> <4497F3DE.7030000@icyb.net.ua>

next in thread | previous in thread | raw e-mail | index | archive | help
on 20/06/2006 16:10 Andriy Gapon said the following:
> 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.
> 

BTW, an interesting link here:
http://www.microsoft.com/whdc/system/CEC/mm-timer.mspx

Some quotes:
8254 PIT
... this timer is only used in periodic mode to provide the periodic
clock interrupt on uni-processor systems. [in Windows]

RTC
... The RTC is used in periodic mode to provide the system profiling
interrupt on uni-processor systems and the clock interrupt on
multi-processor systems. [in Windows]

Not sure about their terminology and how up-to-date this document is,
but I think that they use 8254 for hardclock on non-APIC systems and RTC
 on APIC systems in Windows XP.

-- 
Andriy Gapon



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?44982D3B.9050409>