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1.1 root 1: /* vmparam.h 4.10 81/04/24 */
2:
3: /*
4: * Machine dependent constants
5: */
6: #define NPTEPG (NBPG/(sizeof (struct pte)))
7: /* number of ptes per page */
8: #define USRSTACK (0x80000000-UPAGES*NBPG)
9: /* Start of user stack */
10: #define P1TOP 0x200000 /* boundary between P0 and P1 regions */
11:
12: /*
13: * Virtual memory related constants
14: */
15: #define SLOP 32
16: #define MAXTSIZ (6*2048-SLOP) /* max text size (clicks) */
17: #define MAXDSIZ (12*1024-32-SLOP) /* max data size (clicks) */
18: #define MAXSSIZ (12*1024-32-SLOP) /* max stack size (clicks) */
19:
20: /*
21: * Sizes of the system and user portions of the system page table.
22: */
23: /* SYSPTSIZE IS SILLY; IT SHOULD BE COMPUTED AT BOOT TIME */
24: #define SYSPTSIZE (12*NPTEPG)
25: #define USRPTSIZE (8*NPTEPG)
26:
27: /*
28: * The size of the clock loop.
29: */
30: #define LOOPPAGES (maxfree - firstfree)
31:
32: /*
33: * The time for a process to be blocked before being very swappable.
34: * This is a number of seconds which the system takes as being a non-trivial
35: * amount of real time. You probably shouldn't change this;
36: * it is used in subtle ways (fractions and multiples of it are, that is, like
37: * half of a ``long time'', almost a long time, etc.)
38: * It is related to human patience and other factors which don't really
39: * change over time.
40: */
41: #define MAXSLP 20
42:
43: /*
44: * A swapped in process is given a small amount of core without being bothered
45: * by the page replacement algorithm. Basically this says that if you are
46: * swapped in you deserve some resources. We protect the last SAFERSS
47: * pages against paging and will just swap you out rather than paging you.
48: * Note that each process has at least UPAGES+CLSIZE pages which are not
49: * paged anyways (this is currently 8+2=10 pages or 5k bytes), so this
50: * number just means a swapped in process is given around 25k bytes.
51: * Just for fun: current memory prices are 4600$ a megabyte on VAX (4/22/81),
52: * so we loan each swapped in process memory worth 100$, or just admit
53: * that we don't consider it worthwhile and swap it out to disk which costs
54: * $30/mb or about $0.75.
55: */
56: #define SAFERSS 32 /* nominal ``small'' resident set size
57: protected against replacement */
58:
59: /*
60: * DISKRPM is used to estimate the number of paging i/o operations
61: * which one can expect from a single disk controller.
62: */
63: #define DISKRPM 60
64:
65: /*
66: * Klustering constants. Klustering is the gathering
67: * of pages together for pagein/pageout, while clustering
68: * is the treatment of hardware page size as though it were
69: * larger than it really is.
70: *
71: * KLMAX gives maximum cluster size in CLSIZE page (cluster-page)
72: * units. Note that KLMAX*CLSIZE must be <= DMMIN in dmap.h.
73: */
74:
75: #define KLMAX (32/CLSIZE)
76: #define KLSEQL (16/CLSIZE) /* in klust if vadvise(VA_SEQL) */
77: #define KLIN (8/CLSIZE) /* default data/stack in klust */
78: #define KLTXT (4/CLSIZE) /* default text in klust */
79: #define KLOUT (32/CLSIZE)
80:
81: /*
82: * KLSDIST is the advance or retard of the fifo reclaim for sequential
83: * processes data space.
84: */
85: #define KLSDIST 3 /* klusters advance/retard for seq. fifo */
86:
87: #ifdef KERNEL
88: int klseql;
89: int klsdist;
90: int klin;
91: int kltxt;
92: int klout;
93: #endif
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