[src/trunk]: src/sys/arch/i386/i386 Make the msgbuf initialisation track clos...

[cherry <cherry%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/427bbbdfa3bf
branches:  trunk
changeset: 819999:427bbbdfa3bf
user:      cherry <cherry%NetBSD.org@localhost>
date:      Mon Dec 26 15:47:48 2016 +0000

description:
Make the msgbuf initialisation track closer to the original
pre-uvm_physseg.h one.

To see the exact changes with the original, line for line, do:

cvs rdiff -u -r1.772 -r1.775 src/sys/arch/i386/i386/machdep.c

diffstat:

 sys/arch/i386/i386/machdep.c |  60 +++++++++++++++++++++++++++----------------
 1 files changed, 38 insertions(+), 22 deletions(-)

diffs (85 lines):

diff -r a3a7877b5d72 -r 427bbbdfa3bf sys/arch/i386/i386/machdep.c
--- a/sys/arch/i386/i386/machdep.c      Mon Dec 26 14:53:17 2016 +0000
+++ b/sys/arch/i386/i386/machdep.c      Mon Dec 26 15:47:48 2016 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: machdep.c,v 1.774 2016/12/23 09:24:57 maya Exp $       */
+/*     $NetBSD: machdep.c,v 1.775 2016/12/26 15:47:48 cherry Exp $     */
 
 /*-
  * Copyright (c) 1996, 1997, 1998, 2000, 2004, 2006, 2008, 2009
@@ -67,7 +67,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: machdep.c,v 1.774 2016/12/23 09:24:57 maya Exp $");
+__KERNEL_RCSID(0, "$NetBSD: machdep.c,v 1.775 2016/12/26 15:47:48 cherry Exp $");
 
 #include "opt_beep.h"
 #include "opt_compat_ibcs2.h"
@@ -1037,30 +1037,46 @@
 static void
 init386_msgbuf(void)
 {
-        /* Message buffer is located at end of core. */
-       psize_t reqsz = round_page(MSGBUFSIZE);
-       psize_t sz = 0;
-
-       for (sz = 0; sz < reqsz; sz += PAGE_SIZE) {
-               paddr_t stolenpa;
-
-               if (!uvm_page_physget(&stolenpa))
+       /* Message buffer is located at end of core. */
+       psize_t sz = round_page(MSGBUFSIZE);
+       psize_t reqsz = sz;
+       uvm_physseg_t x;
+               
+search_again:
+        for (x = uvm_physseg_get_first();
+            uvm_physseg_valid_p(x);
+            x = uvm_physseg_get_next(x)) {
+               if (ctob(uvm_physseg_get_avail_end(x)) == avail_end) {
                        break;
-
-               if (stolenpa == (msgbuf_p_seg[msgbuf_p_cnt].paddr
-                       + PAGE_SIZE)) {
-                       /* contiguous: append it to current buf alloc */
-                       msgbuf_p_seg[msgbuf_p_cnt].sz += PAGE_SIZE;
-               } else  {
-                       /* non-contiguous: start a new msgbuf seg */
-                       msgbuf_p_seg[msgbuf_p_cnt].sz = PAGE_SIZE;
-                       msgbuf_p_seg[msgbuf_p_cnt++].paddr = stolenpa;
                }
        }
+       if (uvm_physseg_valid_p(x) == false)
+               panic("init386: can't find end of memory");
 
-       if (sz != reqsz)
-               printf("%s: could only allocate %"PRIxPSIZE" bytes of requested"
-                   " %"PRIxPSIZE" bytes\n", __func__, sz, reqsz);
+       /* Shrink so it'll fit in the last segment. */
+       if (uvm_physseg_get_avail_end(x) - uvm_physseg_get_avail_start(x) < atop(sz))
+               sz = ctob(uvm_physseg_get_avail_end(x) - uvm_physseg_get_avail_start(x));
+
+       uvm_physseg_unplug(uvm_physseg_get_end(x) - atop(sz), atop(sz));
+       msgbuf_p_seg[msgbuf_p_cnt].sz = sz;
+        msgbuf_p_seg[msgbuf_p_cnt++].paddr = ctob(uvm_physseg_get_avail_end(x));
+
+       /* Now find where the new avail_end is. */
+       avail_end = ctob(uvm_physseg_get_avail_end(x));
+
+       if (sz == reqsz)
+               return;
+
+       reqsz -= sz;
+       if (msgbuf_p_cnt == VM_PHYSSEG_MAX) {
+               /* No more segments available, bail out. */
+               printf("WARNING: MSGBUFSIZE (%zu) too large, using %zu.\n",
+                   (size_t)MSGBUFSIZE, (size_t)(MSGBUFSIZE - reqsz));
+               return;
+       }
+
+       sz = reqsz;
+       goto search_again;
 }
 
 #ifndef XEN