Date: Wed, 13 Jun 2001 13:04:01 -0700 (PDT) From: Brad Karp <bkarp@icsi.berkeley.edu> To: freebsd-smp@freebsd.org Subject: clock speedup on 4.3 SMP boxes Message-ID: <200106132004.f5DK41a00672@pynchon.icsi.berkeley.edu>
next in thread | raw e-mail | index | archive | help
I've been experiencing clock speedup (that is, FreeBSD's notion of the current time of day advances faster than real time) on two SMP boxes that run 4.3-RELEASE. The two motherboards: - Tyan S2567, with ServerWorks HEsl chipset - Intel STL2 On both motherboards, I use dual 1 GHz P-IIIs. The clock acceleration appears to be directly proportional to the CPU load on the machine. When I run large simulations that drive one or both CPUs to 100% utilization, the clock gain approaches one hour gain (or more!) per 24 hours real time! Though I run ntpd, ntpd quits once the clock drifts so far so fast, of course. I scoured the -smp archives, assuming that I'd see other reports if this is a kernel SMP code bug. But I found no such reports. At that point, I'd only seen the behavior on the Tyan S2567. So I sent the board to Tyan for repair! Then, I began observing the same behavior on the Intel STL2 board. I now fear that this is an SMP kernel bug. Has anyone seen such clock gains under 4.3, or earlier releases? Many thanks, -Brad, bkarp@icsi.berkeley.edu To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-smp" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200106132004.f5DK41a00672>