Date: Sat, 11 Sep 1999 18:44:01 +0200 From: Christoph Splittgerber <chris@sdata.de> To: freebsd-stable@freebsd.org Subject: Re: URGENT! HEADS UP: 3.3-RC SMP + APM -> FIX Message-ID: <37DA86D1.4AFF1E6F@sdata.de> References: <19990910145217.F0BE61CA8@overcee.netplex.com.au>
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Peter Wemm wrote: > BTW; to quote Linux's Alan Cox on one thread over SMP vs APM problems > and hacks that partially work under Linux: > "APM will never be SMP safe, the problem is at the BIOS level not Linux" > > I've re-read the mpspec 1.4.6 stuff and I can't find a single mention of > APM in it. > > IMHO, it's a pretty safe assumption that APM should not be called for > anything more than things like ATX poweroff under SMP, and even that's > probably best to defer until after all the AP's have been halted. Things > like suspend, cpuclock slowdown, idle showdown etc are seriously bad for > SMP systems as the cpu calling the bios will be the one affected. (eg: a > suspend-to-disk will put the calling CPU into SMI mode and dump it's state > to disk... the other poor cpu's context is going to be lost, and indeed the > other cpu will continue running *during* the suspend-to-disk...) Even if I don't want to use APM, I need the system statistics of cpu% etc. I personally would not care too much if I can't "shutdown -p" etc. but system statistics are mandatory. On my 3.2-stable the trick was no enable "apm0 at isa? flags 0x20" in the kernel config file to get system statistics working (it did not work without the 0x20 flag nor with apm disabled at all). Because this is a production system here I can not cvsup to stable as long as I don't know if SMP (including system statistics) is working again. Can somebody please verify if this is fixed now on -stable. Thanks in advance, Christoph To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message
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