Date: Mon, 04 Apr 2005 09:45:44 -0400 From: Gary Mu1der <gmulder@infotechfl.com> To: freebsd-amd64@freebsd.org Subject: Re: Tyan k8sr lockups Message-ID: <42514508.90303@infotechfl.com> In-Reply-To: <20050401201907.U95587@carver.gumbysoft.com> References: <f0111a98c01333b3c306c81d10294de4@khera.org> <Pine.SOC.4.61.0503300229560.3181@tea.blinkenlights.nl> <3f9aa5aef19c41837cce1563e2c97a21@khera.org> <424C215E.5080201@infotechfl.com> <b6c7cfb181756fdfa3593f64223cb08a@khera.org> <424C4EED.5070601@infotechfl.com> <1112312243.6323.10.camel@lanshark.dmv.com> <424D58F7.1010005@infotechfl.com> <cab069d57aee4d9ba99d5ed9ef6b94c1@khera.org> <424DA4B3.3070703@infotechfl.com> <20050401201907.U95587@carver.gumbysoft.com>
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I had suspected that, but I've done the same on a P4 system with 5.3REL, Solaris on Sparc (although I don't know if Sparc has memory mapped I/O), and other Unixes, and had no problems. It was a quick a dirty way to stress the memory and CPU. Thanks for the reply, Gary Doug White wrote: > On Fri, 1 Apr 2005, Gary Mu1der wrote: > > >>I have isolated the crash to the following dd command: >> >> dd if=/dev/mem of=/dev/null bs=1024k skip=4040 count=1 > > > Reading from random places in /dev/mem will cause unpredicatable behavior. > Memory at that offset is in PCI memory-mapped device space, and reading > from there may disrupt the PCI bridge, enable or disable interrupts, or > worse. >
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