s3: Remove madvise support

This reverts 193be432.  The MADVISE_PROTECT is inherited by all child
processes and cannot be unset.  The intention of the original patch was
to protect the parent process, but allow children to be killed in low
memory.  Since this isn't possible with the current API, reverting the
whole feature.

2 files changed, 0 insertions, 36 deletions

diff --git a/source3/configure.in b/source3/configure.in
index d67feccb9b..e48ff34554 100644
--- a/source3/configure.in
+++ b/source3/configure.in
@@ -4723,35 +4723,6 @@ SMB_LIBRARY(addns, 0, no, [undefined API])
 
 
 #################################################
-# check to see if we should set the protected madvise flag,
-# which will keep smbd alive in low memory conditions
-AC_MSG_CHECKING(whether to protect smbd from being killed in low memory)
-AC_ARG_WITH(madvise-protect,
-[AS_HELP_STRING([--with-madvise-protect], [Include low memory madvise protection (default=no)])],
-[ case "$withval" in
-  yes)
-    AC_TRY_COMPILE([
-        #include <sys/mman.h>
-        ],[
-        int a = MADV_PROTECT;
-        ],
-        [samba_cv_madvise_protect=yes],
-        [samba_cv_madvise_protect=no])
-    if test x"$samba_cv_madvise_protect" = x"yes"; then
-        AC_MSG_RESULT(yes)
-        AC_DEFINE(WITH_MADVISE_PROTECTED,1,[Whether to include low memory protection support])
-    else
-        AC_MSG_ERROR(Low memory protection supporte requires availability of MADVISE_PROTECT flag.)
-    fi
-    ;;
-  *)
-    AC_MSG_RESULT(no)
-    ;;
-  esac ],
-  AC_MSG_RESULT(no)
-)
-
-#################################################
 # these tests are taken from the GNU fileutils package
 AC_CHECKING(how to get filesystem space usage)
 space=no
diff --git a/source3/lib/util.c b/source3/lib/util.c
index 89f7be8e6c..ec794ca74e 100644
--- a/source3/lib/util.c
+++ b/source3/lib/util.c
@@ -899,13 +899,6 @@ bool reinit_after_fork(struct messaging_context *msg_ctx,
 	 * numbers as each other */
 	set_need_random_reseed();
 
-#ifdef WITH_MADVISE_PROTECTED
-	/* Protect parent process from being killed by kernel when system
-	 * memory is low.  Child processes can still be killed */
-	if(!parent_longlived)
-		madvise(NULL,0,MADV_PROTECT);
-#endif
-
 	/* tdb needs special fork handling */
 	if (tdb_reopen_all(parent_longlived ? 1 : 0) == -1) {
 		DEBUG(0,("tdb_reopen_all failed.\n"));