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Xref: sserve comp.os.linux:47860 comp.os.386bsd.questions:3787 comp.sys.ibm.pc.hardware:60183 comp.windows.x.i386unix:2498 Newsgroups: comp.os.linux,comp.os.386bsd.questions,comp.sys.ibm.pc.hardware,comp.windows.x.i386unix Path: sserve!newshost.anu.edu.au!munnari.oz.au!news.Hawaii.Edu!ames!agate!doc.ic.ac.uk!uknet!gdt!aber!fronta.aber.ac.uk!pcg From: pcg@aber.ac.uk (Piercarlo Grandi) Subject: Re: SUMMARY: 486DX2/66 for Unix conclusions (fairly long) In-Reply-To: davidg@implode.rain.com's message of 13 Jul 93 11: 42:41 GMT Message-ID: <PCG.93Jul13210635@decb.aber.ac.uk> Sender: news@aber.ac.uk (USENET news service) Nntp-Posting-Host: decb.aber.ac.uk Reply-To: pcg@aber.ac.uk (Piercarlo Grandi) Organization: Prifysgol Cymru, Aberystwyth References: <CA3pv5.56D@implode.rain.com> Date: Tue, 13 Jul 1993 20:06:35 GMT Lines: 40 >>> On 13 Jul 93 11:42:41 GMT, davidg@implode.rain.com (David Greenman) >>> said: David> Sorry that I missed the original post, but seeing part of the David> following quote, I have to make some corrections to what Chris David> Metcalf and Piercarlo Grandi have said: Chris> o Linux uses the disk better: shared libraries for Chris> executables, and virtual memory is physical memory PLUS disk Chris> swap partitions; 386BSD currently uses unshared libraries Chris> (though apparently some people are working on this), and does Chris> the usual BSD virtual memory technique where all virtual memory Chris> must be backed by swap. David> It is true that 386BSD as it is shipped does not support have David> libraries. It is *not* true that it's total VM must be backed by David> swap. In fact if you want you can have *no* swap. The total VM in David> 386BSD is memory + swap. 386BSD's VM system has nothing in David> common with original BSD; 386BSD's VM system is derived from Mach David> 2.5. What about BSD4.4? pcg> On the other hand Linux does no swapping. However the BSD swapper pcg> sucks, but maybe it's better than nothing. However overall I think pcg> that the VM subsystem is better under BSD than Linux, even if I pcg> would love for it to use page fault frequency as policy. David> This is wrong, too. 386BSD does *not* swap. The swapping code has David> not yet been written. 386BSD only pages. Yes, but doesn't BSD4.4 swap? Or have I got it backwards? The 386BSD VM subsystem is, as far as I know, a very preliminary version of the BSD4.4 one, but the latter is very much improved. Is it that BSD4.4 does no swapping either? The lack of swapping is a terrible thing, even for a single user workstation. Having only paging forces you to have enough real memory for the working sets of all processes, or else thrash. Neither is a nice option...