Date: Wed, 27 Jul 2005 13:28:52 -0400 From: Gary Mu1der <gmulder@infotechfl.com> To: freebsd-amd64@freebsd.org Subject: Re: Tyan S2885 Thunder K8W lockups Message-ID: <42E7C454.8080404@infotechfl.com> In-Reply-To: <200507270814.j6R8E2Mc006780@peedub.jennejohn.org> References: <200507270814.j6R8E2Mc006780@peedub.jennejohn.org>
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Gary Jennejohn wrote: > NAKATA Maho writes: > >>How to lockup: >># dd if=/dev/mem of=/dev/null bs=1024k >>about 50 seconds later it lockups. 100% reproducible. >>* Both Optimal/Failsafe setting in BIOS >>* Both MTRR Mapping Continuous/Disabled >>* set hw.physmem="4G" doesn't help >> >>workaround: >>on board GbE (bge0) and SATA disabled. >> >>any hints or comments? >> > > > I could be wrong, but it seems to me that you might be accessing HW > address space with resulting undesirable side effects since you're > trying to read the entire range which /dev/mem maps. I can confirm I tried the same thing and got the same result with similar hardware. It was also pointed out to me that reading indiscriminately from /dev/mem may screw up memory mapped I/O and likely cause a crash. Gary
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