[BusyBox] init: sysinfo [PATCH]

[Shaun Jackman]

On 7/5/05, Mike Frysinger <vapier at gentoo.org> wrote:
> On Tuesday 05 July 2005 06:17 pm, Jason Schoon wrote:
> > Given that it's difficult to determine who is or isn't using a feature,
> > perhaps for now we could settle for a config option, defaulted to on, such
> > as ENABLE_INIT_SWAPON. That would allow people like me to turn it off to
> > save space, without breaking others.
> 
> good enough for me ... ive never hacked on init before so could someone post a
> patch for this ?

As discussed above.

Cheers,
Shaun

2005-07-05  Shaun Jackman  <sjackman at gmail.com>

	* init/Config.in (CONFIG_FEATURE_INIT_SWAPON): New option.
	* init/init.c (check_memory): Disable the swapon feature unless
	CONFIG_FEATURE_INIT_SWAPON is defined.

--- init/Config.in
+++ init/Config.in
@@ -35,6 +35,14 @@
 	  core file sizes.  If this option is disabled, processes
 	  will not generate any core files.
 
+config CONFIG_FEATURE_INIT_SWAPON
+	bool "  Should init run swapon if short on memory?"
+	default y
+	depends on CONFIG_INIT
+	help
+	  If the system has less than one megabyte of total memory, init
+	  will call /sbin/swapon -a to add swap memory.
+
 config CONFIG_FEATURE_EXTRA_QUIET
 	bool "  Should init be _extra_ quiet on boot?"
 	default y
--- init/init.c
+++ init/init.c
@@ -308,6 +308,7 @@
 	tcsetattr(fd, TCSANOW, &tty);
 }
 
+#ifdef CONFIG_FEATURE_INIT_SWAPON
 /* How much memory does this machine have?
    Units are kBytes to avoid overflow on 4GB machines */
 static unsigned int check_free_memory(void)
@@ -336,6 +337,7 @@
 		return(result * u);
 	}
 }
+#endif /* CONFIG_FEATURE_INIT_SWAPON */
 
 static void console_init(void)
 {
@@ -910,6 +912,7 @@
 	}
 }
 
+#ifdef CONFIG_FEATURE_INIT_SWAPON
 /* Make sure there is enough memory to do something useful. *
  * Calls "swapon -a" if needed so be sure /etc/fstab is present... */
 static void check_memory(void)
@@ -937,6 +940,9 @@
 	message(CONSOLE, "Sorry, your computer does not have enough memory.");
 	loop_forever();
 }
+#else
+# define check_memory()
+#endif /* CONFIG_FEATURE_INIT_SWAPON */
 
 /* NOTE that if CONFIG_FEATURE_USE_INITTAB is NOT defined,
  * then parse_inittab() simply adds in some default