X-Authentication-Warning: delorie.com: mail set sender to djgpp-bounces using -f From: eplmst AT lu DOT erisoft DOT se (Martin Stromberg) Newsgroups: comp.os.msdos.djgpp Subject: Re: HELP with DPMI under DOS - Part II Date: 21 Oct 2003 14:59:36 GMT Organization: Ericsson Erisoft AB, Sweden Lines: 28 Message-ID: References: <3f944c94 DOT sandmann AT clio DOT rice DOT edu> <8N6lb.684$947 DOT 530 AT nntpserver DOT swip DOT net> <3f953833 DOT sandmann AT clio DOT rice DOT edu> NNTP-Posting-Host: lws256.lu.erisoft.se X-Newsreader: TIN [version 1.2 PL2] To: djgpp AT delorie DOT com DJ-Gateway: from newsgroup comp.os.msdos.djgpp Reply-To: djgpp AT delorie DOT com Charles Sandmann (sandmann AT clio DOT rice DOT edu) wrote: : > 5) for Charlies Sandman: I will try to use sbrk(), I use to disable swap : > file I will turn it on again (what about performance?). : When using over 500MB of memory with cwsdpmi r5, the page tables will : fault and cause slower performance. If you have a disk cache, or put a : 2MB swap file on a ram disk you can lower the performance hit. : But the fix for this is to use the current "test" release of cwsdpmi r6: : http://clio.rice.edu/djgpp/csdpmi6t.zip : I haven't messed with it in almost 2 years (not a lot of requests for more : than 500MB of memory under DOS). Eventually I planned to support 4GB, but : I don't have a system with more than 2GB for testing right now. I am : considering making some major memory management changes for the final : release which would limit the 4KB page space to the first 256MB and use : 4MB pages for anything over that. But trying to document that behavior, : which would violate the DPMI specification, is a mess. Why are 4MB pages or swapping the 4KB page tables necessary? Can't you just allocate some memory above 1.1MB and put the page tables that won't fit in conventional memory there? Right, MartinS