From abeeec74b248880c337a3ae71e5fed2eabd77121 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ludovic=20Court=C3=A8s?= <ludo@gnu.org>
Date: Sat, 15 Dec 2018 18:04:27 +0100
Subject: [PATCH] Do not warn the user when 'madvise' returns ENOSYS.

* libguile/vm.c (return_unused_stack_to_os): Avoid 'perror' calls when
'madvise' returns ENOSYS.
---
 libguile/vm.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/libguile/vm.c b/libguile/vm.c
index e9e6ad0c4..82cdae91a 100644
--- a/libguile/vm.c
+++ b/libguile/vm.c
@@ -660,7 +660,10 @@ return_unused_stack_to_os (struct scm_vm *vp)
         ret = madvise ((void *) lo, hi - lo, MADV_DONTNEED);
       while (ret && errno == EAGAIN);
 
-      if (ret)
+      /* If the OS doesn't implement 'madvise' (as is currently the case
+         for GNU/Hurd), don't warn the user since there's nothing they
+         can do about it.  */
+      if (ret && errno != ENOSYS)
         perror ("madvise failed");
     }