+
+/*
+ * Paging thresholds (see vm_sched.c).
+ * Strategy of 1/19/85:
+ * lotsfree is 512k bytes, but at most 1/4 of memory
+ * desfree is 200k bytes, but at most 1/8 of memory
+ * minfree is 64k bytes, but at most 1/2 of desfree
+ */
+#define LOTSFREE (512 * 1024)
+#define LOTSFREEFRACT 4
+#define DESFREE (200 * 1024)
+#define DESFREEFRACT 8
+#define MINFREE (64 * 1024)
+#define MINFREEFRACT 2
+
+/*
+ * There are two clock hands, initially separated by HANDSPREAD bytes
+ * (but at most all of user memory). The amount of time to reclaim
+ * a page once the pageout process examines it increases with this
+ * distance and decreases as the scan rate rises.
+ */
+#define HANDSPREAD (2 * 1024 * 1024)
+
+/*
+ * The number of times per second to recompute the desired paging rate
+ * and poke the pagedaemon.
+ */
+#define RATETOSCHEDPAGING 4
+
+/*
+ * Believed threshold (in megabytes) for which interleaved
+ * swapping area is desirable.
+ */
+#define LOTSOFMEM 2
+
+#define mapin(pte, v, pfnum, prot) \
+ (*(int *)(pte) = (pfnum) | (prot), mtpr(TBIS, v))