[src/trunk]: src/sbin/newfs For MFS, no longer use heuristic based on rlimit ...

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

details:   https://anonhg.NetBSD.org/src/rev/d104f7155c1e
branches:  trunk
changeset: 785523:d104f7155c1e
user:      mlelstv <mlelstv%NetBSD.org@localhost>
date:      Sun Mar 17 12:25:36 2013 +0000

description:
For MFS, no longer use heuristic based on rlimit to determine mmap size.
This is no longer functional with current memory allocation routines.

diffstat:

 sbin/newfs/mkfs.c |  65 +++++++++++++++++++++---------------------------------
 1 files changed, 25 insertions(+), 40 deletions(-)

diffs (114 lines):

diff -r 2682c81de5b9 -r d104f7155c1e sbin/newfs/mkfs.c
--- a/sbin/newfs/mkfs.c Sun Mar 17 12:19:57 2013 +0000
+++ b/sbin/newfs/mkfs.c Sun Mar 17 12:25:36 2013 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: mkfs.c,v 1.113 2013/01/22 09:39:12 dholland Exp $      */
+/*     $NetBSD: mkfs.c,v 1.114 2013/03/17 12:25:36 mlelstv Exp $       */
 
 /*
  * Copyright (c) 1980, 1989, 1993
@@ -73,7 +73,7 @@
 #if 0
 static char sccsid[] = "@(#)mkfs.c     8.11 (Berkeley) 5/3/95";
 #else
-__RCSID("$NetBSD: mkfs.c,v 1.113 2013/01/22 09:39:12 dholland Exp $");
+__RCSID("$NetBSD: mkfs.c,v 1.114 2013/03/17 12:25:36 mlelstv Exp $");
 #endif
 #endif /* not lint */
 
@@ -121,7 +121,6 @@
 static int ilog2(int);
 static void zap_old_sblock(int);
 #ifdef MFS
-static void calc_memfree(void);
 static void *mkfs_malloc(size_t size);
 #endif
 
@@ -191,9 +190,6 @@
 #endif
 #ifdef MFS
        if (mfs && !Nflag) {
-               calc_memfree();
-               if ((uint64_t)fssize * sectorsize > memleft)
-                       fssize = memleft / sectorsize;
                if ((membase = mkfs_malloc(fssize * sectorsize)) == NULL)
                        exit(12);
        }
@@ -1625,33 +1621,6 @@
 
 #ifdef MFS
 /*
- * XXX!
- * Attempt to guess how much more space is available for process data.  The
- * heuristic we use is
- *
- *     max_data_limit - (sbrk(0) - etext) - 128kB
- *
- * etext approximates that start address of the data segment, and the 128kB
- * allows some slop for both segment gap between text and data, and for other
- * (libc) malloc usage.
- */
-static void
-calc_memfree(void)
-{
-       extern char etext;
-       struct rlimit rlp;
-       u_long base;
-
-       base = (u_long)sbrk(0) - (u_long)&etext;
-       if (getrlimit(RLIMIT_DATA, &rlp) < 0)
-               perror("getrlimit");
-       rlp.rlim_cur = rlp.rlim_max;
-       if (setrlimit(RLIMIT_DATA, &rlp) < 0)
-               perror("setrlimit");
-       memleft = rlp.rlim_max - base - (128 * 1024);
-}
-
-/*
  * Internal version of malloc that trims the requested size if not enough
  * memory is available.
  */
@@ -1659,20 +1628,36 @@
 mkfs_malloc(size_t size)
 {
        u_long pgsz;
-       caddr_t *memory;
+       caddr_t *memory, *extra;
+       size_t exsize = 128 * 1024;
 
        if (size == 0)
                return (NULL);
-       if (memleft == 0)
-               calc_memfree();
 
        pgsz = getpagesize() - 1;
        size = (size + pgsz) &~ pgsz;
-       if (size > memleft)
-               size = memleft;
-       memleft -= size;
+
+       /* try to map requested size */
        memory = mmap(0, size, PROT_READ|PROT_WRITE, MAP_ANON|MAP_PRIVATE,
            -1, 0);
-       return memory != MAP_FAILED ? memory : NULL;
+       if (memory == MAP_FAILED)
+               return NULL;
+
+       /* try to map something extra */
+       extra = mmap(0, exsize, PROT_READ|PROT_WRITE, MAP_ANON|MAP_PRIVATE,
+           -1, 0);
+       munmap(extra, exsize);
+
+       /* if extra memory couldn't be mapped, reduce original request accordingly */
+       if (extra == MAP_FAILED) {
+               munmap(memory, size);
+               size -= exsize;
+               memory = mmap(0, size, PROT_READ|PROT_WRITE, MAP_ANON|MAP_PRIVATE,
+                   -1, 0);
+               if (memory == MAP_FAILED)
+                       return NULL;
+       }
+
+       return memory;
 }
 #endif /* MFS */