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Xref: sserve comp.unix.bsd:14106 comp.os.mach:3924 Path: sserve!newshost.anu.edu.au!harbinger.cc.monash.edu.au!msuinfo!agate!howland.reston.ans.net!swrinde!pipex!sunic!news.funet.fi!nntp.hut.fi!nntp!jvh From: jvh@cs.hut.fi (Johannes Helander) Newsgroups: comp.unix.bsd,comp.os.mach Subject: BSD vm (Re: Anyone using MachTen on a Mac?) Date: 05 Jun 1994 23:21:51 GMT Organization: Helsinki University of Technology, CS Lab. Lines: 30 Distribution: inet Message-ID: <JVH.94Jun6022152@hutcs.cs.hut.fi> References: <1994Jun3.210215.20699@midway.uchicago.edu> <2sp809$hnq@xochi.tezcat.com> <1994Jun4.091322.13685@midway.uchicago.edu> <2sruh6$hnh@news.u.washington.edu> <2ss0lm$54s@xochi.tezcat.com> <VIXIE.94Jun5145032@office.home.vix.com> NNTP-Posting-Host: hutcs.cs.hut.fi In-reply-to: vixie@vix.com's message of 5 Jun 94 14:50:32 In article <VIXIE.94Jun5145032@office.home.vix.com> vixie@vix.com (Paul A Vixie) writes: > "Based heavily" might be too strong a wording. BNR2 included the Mach 2.5 > "pmap" code, with lots of local modifications to get it to fit into the BSD > kernel "style" and also increase performance (which wasn't really a concern > for the Mach folks). The mmap() stuff was also borrowed somewhat from Mach, The vm_objects, vm_maps, vm_fault, etc. are a much more significant part. The pmap layer is just the lowest machine dependent part that manages the actual page tables and physical page allocations. Mapping, copy on write, inheritance, sharing, lookup, etc are managed by the machine independent layers. > but modified even more radically. Not being familiar with all the details I'd say it was basically unixified. This includes changing the application interface and gluing the code together with vnodes, the buffer cache etc. The performance improvements are indeed valuable but the application interface changes I wouldn't call improvement. > Pmap is an ugly hairy nasty mess. At least it isolates the machine dependent mess from the rest of the system. As for the machine independent code it might be hairy but if you call it ugly you could as well call 99%+ of all software ugly (not necessarily untrue). Johannes