diff --git a/src/auto/configure b/src/auto/configure
index 43c161b..5659d38 100755
--- a/src/auto/configure
+++ b/src/auto/configure
@@ -13688,6 +13688,62 @@
 fi
 rm -f conftest.err conftest.$ac_objext conftest.$ac_ext
 
+echo "$as_me:$LINENO: checking for sysinfo.mem_unit" >&5
+echo $ECHO_N "checking for sysinfo.mem_unit... $ECHO_C" >&6
+cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+#include <sys/types.h>
+#include <sys/sysinfo.h>
+int
+main ()
+{
+	struct sysinfo sinfo;
+ 	sinfo.mem_unit = 1;
+
+  ;
+  return 0;
+}
+_ACEOF
+rm -f conftest.$ac_objext
+if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
+  (eval $ac_compile) 2>conftest.er1
+  ac_status=$?
+  grep -v '^ *+' conftest.er1 >conftest.err
+  rm -f conftest.er1
+  cat conftest.err >&5
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } &&
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; } &&
+	 { ac_try='test -s conftest.$ac_objext'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; }; then
+  echo "$as_me:$LINENO: result: yes" >&5
+echo "${ECHO_T}yes" >&6; cat >>confdefs.h <<\_ACEOF
+#define HAVE_SYSINFO_MEM_UNIT 1
+_ACEOF
+
+else
+  echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+echo "$as_me:$LINENO: result: no" >&5
+echo "${ECHO_T}no" >&6
+fi
+rm -f conftest.err conftest.$ac_objext conftest.$ac_ext
+
 echo "$as_me:$LINENO: checking for sysconf" >&5
 echo $ECHO_N "checking for sysconf... $ECHO_C" >&6
 cat >conftest.$ac_ext <<_ACEOF
diff --git a/src/config.h.in b/src/config.h.in
index 9b42b92..3d9e162 100644
--- a/src/config.h.in
+++ b/src/config.h.in
@@ -176,6 +176,7 @@
 #undef HAVE_SYSCONF
 #undef HAVE_SYSCTL
 #undef HAVE_SYSINFO
+#undef HAVE_SYSINFO_MEM_UNIT
 #undef HAVE_TGETENT
 #undef HAVE_TOWLOWER
 #undef HAVE_TOWUPPER
diff --git a/src/configure.in b/src/configure.in
index 66f6295..0af26bd 100644
--- a/src/configure.in
+++ b/src/configure.in
@@ -2590,6 +2590,17 @@
 	AC_MSG_RESULT(yes); AC_DEFINE(HAVE_SYSINFO),
 	AC_MSG_RESULT(not usable))
 
+dnl struct sysinfo may have the mem_unit field or not
+AC_MSG_CHECKING(for sysinfo.mem_unit)
+AC_TRY_COMPILE(
+[#include <sys/types.h>
+#include <sys/sysinfo.h>],
+[	struct sysinfo sinfo;
+ 	sinfo.mem_unit = 1;
+	],
+	AC_MSG_RESULT(yes); AC_DEFINE(HAVE_SYSINFO_MEM_UNIT),
+	AC_MSG_RESULT(no))
+
 dnl sysconf() may exist but not support what we want to use
 AC_MSG_CHECKING(for sysconf)
 AC_TRY_COMPILE(
diff --git a/src/option.c b/src/option.c
index 3be5612..87cf5f6 100644
--- a/src/option.c
+++ b/src/option.c
@@ -3030,7 +3030,7 @@
 #else
 # ifdef HAVE_TOTAL_MEM
 	    /* Use amount of memory available to Vim. */
-	    n = (mch_total_mem(FALSE) >> 11);
+	    n = (mch_total_mem(FALSE) >> 1);
 # else
 	    n = (0x7fffffff >> 11);
 # endif
diff --git a/src/os_unix.c b/src/os_unix.c
index 5195b6b..a188452 100644
--- a/src/os_unix.c
+++ b/src/os_unix.c
@@ -428,8 +428,8 @@
 # endif
 
 /*
- * Return total amount of memory available.  Doesn't change when memory has
- * been allocated.
+ * Return total amount of memory available in Kbyte.
+ * Doesn't change when memory has been allocated.
  */
 /* ARGSUSED */
     long_u
@@ -437,9 +437,10 @@
     int special;
 {
 # ifdef __EMX__
-    return ulimit(3, 0L);   /* always 32MB? */
+    return ulimit(3, 0L) >> 10;   /* always 32MB? */
 # else
     long_u	mem = 0;
+    long_u	shiftright = 10;  /* how much to shift "mem" right for Kbyte */
 
 #  ifdef HAVE_SYSCTL
     int		mib[2], physmem;
@@ -460,7 +461,19 @@
 
 	/* Linux way of getting amount of RAM available */
 	if (sysinfo(&sinfo) == 0)
+	{
+#   ifdef HAVE_SYSINFO_MEM_UNIT
+	    /* avoid overflow as much as possible */
+	    while (shiftright > 0 && (sinfo.mem_unit & 1) == 0)
+	    {
+		sinfo.mem_unit = sinfo.mem_unit >> 1;
+		--shiftright;
+	    }
+	    mem = sinfo.totalram * sinfo.mem_unit;
+#   else
 	    mem = sinfo.totalram;
+#   endif
+	}
     }
 #  endif
 
@@ -473,7 +486,15 @@
 	pagesize = sysconf(_SC_PAGESIZE);
 	pagecount = sysconf(_SC_PHYS_PAGES);
 	if (pagesize > 0 && pagecount > 0)
+	{
+	    /* avoid overflow as much as possible */
+	    while (shiftright > 0 && (pagesize & 1) == 0)
+	    {
+		pagesize = pagesize >> 1;
+		--shiftright;
+	    }
 	    mem = (long_u)pagesize * pagecount;
+	}
     }
 #  endif
 
@@ -488,15 +509,18 @@
 #   ifdef RLIM_INFINITY
 		&& rlp.rlim_cur != RLIM_INFINITY
 #   endif
-		&& (long_u)rlp.rlim_cur < mem
+		&& ((long_u)rlp.rlim_cur >> 10) < (mem >> shiftright)
 	   )
-	    return (long_u)rlp.rlim_cur;
+	{
+	    mem = (long_u)rlp.rlim_cur;
+	    shiftright = 10;
+	}
     }
 #  endif
 
     if (mem > 0)
-	return mem;
-    return (long_u)0x7fffffff;
+	return mem >> shiftright;
+    return (long_u)0x1fffff;
 # endif
 }
 #endif
diff --git a/src/version.c b/src/version.c
index 8e6c550..4152b50 100644
--- a/src/version.c
+++ b/src/version.c
@@ -667,6 +667,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    236,
+/**/
     235,
 /**/
     234,