aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorByungchul Park <byungchul.park@lge.com>2017-10-25 17:56:02 +0900
committerIngo Molnar <mingo@kernel.org>2017-10-25 12:19:02 +0200
commite121d64e16484d4a5eba94cd2fa9eb3848b7c9c2 (patch)
treecd5a01b328ca0c2337aa035a0e0c2b11a38e9e4d
parent2dcd5adfb7401b762ddbe4b86dcacc2f3de6b97b (diff)
download96b-common-e121d64e16484d4a5eba94cd2fa9eb3848b7c9c2.tar.gz
locking/lockdep: Introduce CONFIG_BOOTPARAM_LOCKDEP_CROSSRELEASE_FULLSTACK=y
Add a Kconfig knob that enables the lockdep "crossrelease_fullstack" boot parameter. Suggested-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Byungchul Park <byungchul.park@lge.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: amir73il@gmail.com Cc: axboe@kernel.dk Cc: darrick.wong@oracle.com Cc: david@fromorbit.com Cc: hch@infradead.org Cc: idryomov@gmail.com Cc: johan@kernel.org Cc: johannes.berg@intel.com Cc: kernel-team@lge.com Cc: linux-block@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Cc: linux-mm@kvack.org Cc: linux-xfs@vger.kernel.org Cc: oleg@redhat.com Cc: tj@kernel.org Link: http://lkml.kernel.org/r/1508921765-15396-7-git-send-email-byungchul.park@lge.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
-rw-r--r--kernel/locking/lockdep.c4
-rw-r--r--lib/Kconfig.debug15
2 files changed, 19 insertions, 0 deletions
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 160b5d6df7cb..db933d063bfc 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -76,7 +76,11 @@ module_param(lock_stat, int, 0644);
#define lock_stat 0
#endif
+#ifdef CONFIG_BOOTPARAM_LOCKDEP_CROSSRELEASE_FULLSTACK
+static int crossrelease_fullstack = 1;
+#else
static int crossrelease_fullstack;
+#endif
static int __init allow_crossrelease_fullstack(char *str)
{
crossrelease_fullstack = 1;
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index c1e720a22c71..2b439a515c30 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1179,6 +1179,21 @@ config LOCKDEP_COMPLETIONS
A deadlock caused by wait_for_completion() and complete() can be
detected by lockdep using crossrelease feature.
+config BOOTPARAM_LOCKDEP_CROSSRELEASE_FULLSTACK
+ bool "Enable the boot parameter, crossrelease_fullstack"
+ depends on LOCKDEP_CROSSRELEASE
+ default n
+ help
+ The lockdep "cross-release" feature needs to record stack traces
+ (of calling functions) for all acquisitions, for eventual later
+ use during analysis. By default only a single caller is recorded,
+ because the unwind operation can be very expensive with deeper
+ stack chains.
+
+ However a boot parameter, crossrelease_fullstack, was
+ introduced since sometimes deeper traces are required for full
+ analysis. This option turns on the boot parameter.
+
config DEBUG_LOCKDEP
bool "Lock dependency engine debugging"
depends on DEBUG_KERNEL && LOCKDEP