Add generic exit-time stack-depth checking to CONFIG_DEBUG_STACK_USAGE

Add generic exit-time stack-depth checking to CONFIG_DEBUG_STACK_USAGE.

This also adds UML support.

Tested on UML and i386.

[akpm@linux-foundation.org: cleanups, speedups, tweaks]
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 10 insertions, 0 deletions

diff --git a/arch/um/Kconfig.debug b/arch/um/Kconfig.debug
index 09c1aca6339f..c86f5eb29fd5 100644
--- a/arch/um/Kconfig.debug
+++ b/arch/um/Kconfig.debug
@@ -47,4 +47,13 @@ config GCOV
         If you're involved in UML kernel development and want to use gcov,
         say Y.  If you're unsure, say N.
 
+config DEBUG_STACK_USAGE
+        bool "Stack utilization instrumentation"
+        default N
+        help
+          Track the maximum kernel stack usage - this will look at each
+          kernel stack at process exit and log it if it's the deepest
+          stack seen so far.
+
+          This option will slow down process creation and destruction somewhat.
 endmenu
diff --git a/arch/um/defconfig b/arch/um/defconfig
index a54d0efecae1..e5b2df9e12de 100644
--- a/arch/um/defconfig
+++ b/arch/um/defconfig
@@ -527,3 +527,4 @@ CONFIG_FORCED_INLINING=y
 # CONFIG_RCU_TORTURE_TEST is not set
 # CONFIG_GPROF is not set
 # CONFIG_GCOV is not set
+# CONFIG_DEBUG_STACK_USAGE is not set