[PATCH 2/2] lockdep: allow user to disable CONFIG_TRACE_IRQFLAGS

From: tom . leiming
Date: Tue May 04 2010 - 12:02:59 EST


From: Ming Lei <tom.leiming@xxxxxxxxx>

There is still the lost irq-on tracing issue on ARM,
(see http://marc.info/?l=linux-arm-kernel&m=126047420005553&w=2)
which may disable lockdep after kernel boot, seems no
good solution for the issue up to now.

The patch exports the config option of CONFIG_TRACE_IRQFLAGS
and allows user to disable it for support of checking circular
dead lock only if irq flags tracing can't work correctly always.

Signed-off-by: Ming Lei <tom.leiming@xxxxxxxxx>
---
lib/Kconfig.debug | 3 +++
lib/locking-selftest.c | 2 ++
2 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 935248b..448f18f 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -550,11 +550,14 @@ config DEBUG_LOCKDEP
of more runtime overhead.

config TRACE_IRQFLAGS
+ bool "Lock prove: IRQ flags tracing"
depends on DEBUG_KERNEL
bool
default y
depends on TRACE_IRQFLAGS_SUPPORT
depends on PROVE_LOCKING
+ help
+ If you say Y here, IRQ flags will be traced to prove locking.

config DEBUG_SPINLOCK_SLEEP
bool "Spinlock debugging: sleep-inside-spinlock checking"
diff --git a/lib/locking-selftest.c b/lib/locking-selftest.c
index 619313e..d9e5bfe 100644
--- a/lib/locking-selftest.c
+++ b/lib/locking-selftest.c
@@ -1176,6 +1176,7 @@ void locking_selftest(void)

printk(" --------------------------------------------------------------------------\n");

+#ifdef CONFIG_TRACE_IRQFLAGS
/*
* irq-context testcases:
*/
@@ -1188,6 +1189,7 @@ void locking_selftest(void)

DO_TESTCASE_6x2("irq read-recursion", irq_read_recursion);
// DO_TESTCASE_6x2B("irq read-recursion #2", irq_read_recursion2);
+#endif

if (unexpected_testcase_failures) {
printk("-----------------------------------------------------------------\n");
--
1.6.2.5

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