Date: Sat, 13 Mar 1999 01:10:03 -0800 (PST) From: "Daniel C. Sobral" <dcs@newsguy.com> To: freebsd-bugs@FreeBSD.org Subject: Re: kern/10565: Slow timekeeping on certain motherboards/cpus/chipsets Message-ID: <199903130910.BAA22377@freefall.freebsd.org>
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The following reply was made to PR kern/10565; it has been noted by GNATS. From: "Daniel C. Sobral" <dcs@newsguy.com> To: junki@qn-lpr2-98.quicknet.inet.fi Cc: FreeBSD-gnats-submit@FreeBSD.ORG Subject: Re: kern/10565: Slow timekeeping on certain motherboards/cpus/chipsets Date: Sat, 13 Mar 1999 17:57:12 +0900 Would you happen to have apm enabled in these computers? Juha Nurmela wrote: > > >Number: 10565 > >Category: kern > >Synopsis: Slow timekeeping on certain motherboards/cpus/chipsets > >Confidential: no > >Severity: non-critical > >Priority: low > >Responsible: freebsd-bugs > >State: open > >Quarter: > >Keywords: > >Date-Required: > >Class: change-request > >Submitter-Id: current-users > >Arrival-Date: Fri Mar 12 19:30:00 PST 1999 > >Closed-Date: > >Last-Modified: > >Originator: Juha Nurmela > >Release: FreeBSD 4.0-CURRENT i386 > >Organization: > ACME Inc. > >Environment: > > Timecounter "i8254" frequency 1193182 Hz > Timecounter "TSC" frequency 74539244 Hz > CPU: AMD K5 model 0 (74.54-MHz 586-class CPU) > Origin = "AuthenticAMD" Id = 0x500 Stepping=0 > Features=0x3bf<FPU,VME,DE,PSE,TSC,MSR,MCE,CX8,APIC> > > chip0: <Intel 82437VX PCI cache memory controller> rev 0x02 on pci0.0.0 > chip1: <Intel 82371SB PCI to ISA bridge> rev 0x01 on pci0.7.0 > > >Description: > > Time does not increment. Well, very slowly and not in any determinable > constant rate. Using the timerchip for timecounter instead > of tsc register works around the problem. > > Another 'fix' with my mobo is to keep the cpu busy, and not let > it enter HLT. 'while : ; do date; done' almost does the trick as > well as a idle-priority process in tight loop (does it better). > > Looks like the mobo does bad SMI stuff whenever a HLT is executed, > and it cannot really be changed in the bios settings which disable > power management. > > >How-To-Repeat: > > With this kind of PC, build a kernel which contains no apm0, > nor SMP, and watch date in idlish system, then in busyish system. > Date should step almost properly in busy state and halt > almost completely in idle system. > > >Fix: > > It might be nice to have a std way to set the existing hlt_vector in > swtch.s into just RET (which it already is with SMP). > options "CPU_HALT_NO" and/or > sysctl -w machdep.do_halt=0 > cp_time[] via sysctl would be nice too... > > >Release-Note: > >Audit-Trail: > >Unformatted: > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-bugs" in the body of the message -- Daniel C. Sobral (8-DCS) dcs@newsguy.com dcs@freebsd.org "My theory is that his ignorance clouded his poor judgment." To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-bugs" in the body of the message
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