improve PH entry, per Bill Hacker's suggestion

[users/jgh/exim.git] / src / OS / os.h-Linux

diff --git a/src/OS/os.h-Linux b/src/OS/os.h-Linux
index 5b731eaa1144761d0c32274e9c5b6dd7c65c45e3..fe4eaa6c76f8c9bed210f1bdaee8b3e38795992a 100644 (file)
--- a/src/OS/os.h-Linux
+++ b/src/OS/os.h-Linux
@@ -1,16 +1,27 @@
-/* $Cambridge: exim/src/OS/os.h-Linux,v 1.4 2006/10/30 22:06:33 tom Exp $ */
-
 /* Exim: OS-specific C header file for Linux */
 
+/* Some old systems we've received bug-reports for have a <limits.h> which
+does not pull in <features.h>.  Best to just pull it in now and have done
+with the issue. */
+
+#include <features.h>
+
+
 #define CRYPT_H
 #define GLIBC_IP_OPTIONS
 #define HAVE_MMAP
 #define HAVE_BSD_GETLOADAVG
 #define HAVE_SYS_STATVFS_H
-#define HAVE_LINUX_SENDFILE
 #define NO_IP_VAR_H
 #define SIG_IGN_WORKS
 
+/* When using the DKIM, setting HAVE_LINUX_SENDFILE can increase
+performance on outgoing mail a bit. Note: With older glibc versions
+this setting will conflict with the _FILE_OFFSET_BITS=64 setting
+defined as part of the Linux CFLAGS. */
+
+/* #define HAVE_LINUX_SENDFILE */
+
 #define F_FREESP     O_TRUNC
 typedef struct flock flock_t;