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Newsgroups: comp.os.386bsd.bugs Path: sserve!newshost.anu.edu.au!munnari.oz.au!spool.mu.edu!agate!ames!purdue!mozo.cc.purdue.edu!staff.cc.purdue.edu!bj From: bj@staff.cc.purdue.edu (Ben Jackson) Subject: vm_pageout bug in FreeBSD 1.1.5R? Sender: news@mozo.cc.purdue.edu (USENET News) Message-ID: <CsLyvD.3Eu@mozo.cc.purdue.edu> Date: Fri, 8 Jul 1994 06:18:49 GMT Organization: Purdue University Lines: 39 I've tried several things in an attempt to isolate the kernel panic (`page fault in supervisor mode') problem I'm having with FreeBSD 1.1.5R on my PCI 486/66 w/16M. So far the most conclusive results are that it only panics after it begins to use swap space. I successfully raytraced for 3+ hours one day, and then started X and intentionally consumed enough memory to start swapping and got a panic almost immediately. I've configured in more swap partitions (on nonexistant IDE drives) to see if there was an IDE dependancy. No difference. I disabled swapping on my second drive. No difference. I (rather pessimistically, I admit) built a kernel with `options NOBOUNCE'. No difference. I've configured kernels without SYSV* options enabled. No difference! Arrgh! This happens with both the GENERICAH kernel (I have a 1542Cf) and my normal configuration file (which I'm using with 1.1R with no problems). I built a version of my kernel today with DDB, since I rarely get dumps from the crashes, and when I do savecore rarely saves them (it usually complains about /dev/wd0a not being configured, which is true, since I have no IDE drives, but non-sequiter). After numerous reboots and only minimal effort to cause the problem, I've been able to poke though the kernel after several of these panics. There seems to be a strange "speed" dependancy. If I consume memory using `while :; do emacs &; done', I get a panic in the trap code as it tries to access the page in vm_page_lookup(). If I do it more slowly, I get stopped in vm_pageout_scan(), called from vm_pageout() called from main(). DDB and I aren't on the same wavelengh, so I haven't been able to get any more detailed information out of it, and unfortunately the 1.1R vm_pageout.c is radically different, which makes it difficult to isolate the problem. Does anyone have any suggestions on how I might narrow my search? Have there been any patches to the vm system since 1.1.5 came out? Thanks! -- Ben Jackson, bj@cc.purdue.edu