[PATCH] prohibit rcutorture from being compiled into the kernel

["Paul E. McKenney" <paulmck@linux.vnet.ibm.com>]

Hello!

There have been a number of instances where people have accidentally
compiled rcutorture into the kernel (CONFIG_RCU_TORTURE_TEST=y), which
has never been useful, and has often resulted in great frustration.  The
attached patch prohibits rcutorture from being compiled into the kernel.
It may be excluded altogether or compiled as a module.  People wishing
to have rcutorture hammer their machine immediately upon boot are free
to hand-edit lib/Kconfig.debug to remove the "depends on m" line.

Thanks to Randy Dunlap for the trick that makes this work.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
---

 Kconfig.debug |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff -urpNa -X dontdiff linux-2.6.21/lib/Kconfig.debug linux-2.6.21-rcutorturemodonly/lib/Kconfig.debug
--- linux-2.6.21/lib/Kconfig.debug	2007-04-25 20:08:32.000000000 -0700
+++ linux-2.6.21-rcutorturemodonly/lib/Kconfig.debug	2007-05-15 17:17:14.000000000 -0700
@@ -382,14 +382,13 @@ config FORCED_INLINING
 config RCU_TORTURE_TEST
 	tristate "torture tests for RCU"
 	depends on DEBUG_KERNEL
+	depends on m
 	default n
 	help
 	  This option provides a kernel module that runs torture tests
 	  on the RCU infrastructure.  The kernel module may be built
 	  after the fact on the running kernel to be tested, if desired.
 
-	  Say Y here if you want RCU torture tests to start automatically
-	  at boot time (you probably don't).
 	  Say M if you want the RCU torture tests to build as a module.
 	  Say N if you are unsure.