There is a bug left in the FD-Himem.exe memory manager. When a program that had allocated several XMS blocks doesn't release these blocks in the order FD-Himem likes it, it will report a too small "largest free block". Luckily the memory is not "permanently" lost, FD-Himem is able to regenerate if certain conditions are met.
This is a snapshot of the FD-XMS handle table after DOOM was launched and terminated: ---------------------------------------------------------------------- XMS version: 0300h XMS3+ largest free block (kB): 702036 <-------- BAD XMS3+ highest address: 2FFF0000 XMS3+ total extended memory (kB): 783957 no handle region size(kB) locks flags ------------------------------------------------------- 1 07A9 00110000-0022ABFF 1131 1 02 used 2 07B3 0022AC00-0025ABFF 192 1 02 used 3 07BD 0025AC00-023DAFFF 34305 0 01 free 4 07C7 00000000-00000000 0 0 01 free 5 07D1 023DB000-0255AFFF 1536 0 01 free 6 07DB 0255B000-0285AFFF 3072 0 01 free 7 07E5 0285B000-02E5AFFF 6144 0 01 free 8 07EF 02E5B000-03A5AFFF 12288 0 01 free 9 07F9 03A5B000-0525AFFF 24576 0 01 free 10 0803 0525B000-2FFEFFFF 702036 0 01 free 11 080D 00000000-00000000 0 0 01 free 12 0817 00000000-00000000 0 0 01 free 13 0821 00000000-00000000 0 0 01 free 14 082B 00000000-00000000 0 0 01 free 15 0835 00000000-00000000 0 0 01 free 16 083F 00000000-00000000 0 0 01 free 17 0849 00000000-00000000 0 0 01 free ... ---------------------------------------------------------------------- As it can be seen, the largest block is 80 MB too small. What's bad, a try to alloc 750 MB will fail now. One first has to alloc smaller chunks until Himem is cured again. As a comparison, if one does the same procedure with MS Himem, the table looks like this after DOOM: ---------------------------------------------------------------------- XMS version: 0300h XMS3+ largest free block (kB): 783888 <------------- GOOD XMS3+ highest address: 000B02DF XMS3+ total extended memory (kB): 783888 no handle region size(kB) locks flags ------------------------------------------------------- 1 D58E 00110000-00110FFF 4 1 02 used 2 D598 00111000-00140FFF 192 1 02 used 3 D5A2 00141000-0026BFFF 1196 0 02 used 4 D5AC 0026D000-2FFEFFFF 783884 0 04 unused 5 D5B6 041AC800-0422D7FF 516 0 04 unused 6 D5C0 0422D800-0432E7FF 1028 0 04 unused 7 D5CA 0432E800-0452F7FF 2052 0 04 unused 8 D5D4 0452F800-049307FF 4100 0 04 unused 9 D5DE 04930800-051327FF 8200 0 04 unused 10 D5E8 05132800-06134BFF 16393 0 04 unused 11 D5F2 06134C00-2FFEFFFF 686829 0 04 unused 12 D5FC 2413EC00-2813E7FF 65535 0 04 unused 13 D606 2813E800-2C13E3FF 65535 0 04 unused 14 D610 2C13E400-2FFEFFFF 64199 0 04 unused 16 D624 00000000-00000000 0 0 04 unused 17 D62E 00000000-00000000 0 0 04 unused ... ------------------------------------------------------- This is much better (although there is a bug in MS-Himem with the "highest address" value) ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys -- and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user
