support for BUFCACHEPERCENT

diff --git a/sys/arch/sun3/sun3/machdep.c b/sys/arch/sun3/sun3/machdep.c
index ecd655d..77922cb 100644 (file)
--- a/sys/arch/sun3/sun3/machdep.c
+++ b/sys/arch/sun3/sun3/machdep.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: machdep.c,v 1.16 1997/02/03 23:22:38 kstailey Exp $   */
+/*     $OpenBSD: machdep.c,v 1.17 1997/02/06 20:00:43 kstailey Exp $   */
 /*     $NetBSD: machdep.c,v 1.77 1996/10/13 03:47:51 christos Exp $    */
 
 /*
@@ -206,22 +206,37 @@ allocsys(v)
        valloc(msqids, struct msqid_ds, msginfo.msgmni);
 #endif
 
+#ifndef BUFCACHEPERCENT
+#define BUFCACHEPERCENT 5
+#endif
        /*
-        * Determine how many buffers to allocate. We allocate
+        * Determine how many buffers to allocate. By default we allocate
         * the BSD standard of use 10% of memory for the first 2 Meg,
-        * 5% of remaining. Insure a minimum of 16 buffers.
+        * 5% of remaining.  But this might cause systems with large 
+        * core (32MB) to fail to boot due to small KVM space.  Reduce
+        * BUFCACHEPERCENT in this case.
+        * Insure a minimum of 16 buffers.
         * Allocate 1/2 as many swap buffer headers as file i/o buffers.
         */
        if (bufpages == 0) {
                /* We always have more than 2MB of memory. */
-               bufpages = ((btoc(2 * 1024 * 1024) + physmem) /
-                           (20 * CLSIZE));
+               bufpages = (btoc(2 * 1024 * 1024) + physmem) /
+                       ((100/BUFCACHEPERCENT) * CLSIZE);
        }
        if (nbuf == 0) {
                nbuf = bufpages;
                if (nbuf < 16)
                        nbuf = 16;
        }
+       /* Restrict to at most 70% filled kvm */
+       if (nbuf * MAXBSIZE >
+           (VM_MAX_KERNEL_ADDRESS-VM_MIN_KERNEL_ADDRESS) * 7 / 10)
+               nbuf = (VM_MAX_KERNEL_ADDRESS-VM_MIN_KERNEL_ADDRESS) /
+                       MAXBSIZE * 7 / 10;
+       
+       /* More buffer pages than fits into the buffers is senseless.  */
+       if (bufpages > nbuf * MAXBSIZE / CLBYTES)
+               bufpages = nbuf * MAXBSIZE / CLBYTES;
        if (nswbuf == 0) {
                nswbuf = (nbuf / 2) &~ 1;       /* force even */
                if (nswbuf > 256)
@@ -628,6 +643,7 @@ sendsig(catcher, sig, mask, code, type, val)
                kfp->sf_sip = &fp->sf_si;
                initsiginfo(&kfp->sf_si, sig, code, type, val);
        }
+       /* XXX do not copy out siginfo if not needed */
        (void) copyout((caddr_t)kfp, (caddr_t)fp, fsize);
        frame->f_regs[SP] = (int)fp;
 #ifdef DEBUG