Commit-ID: e121d64e16484d4a5eba94cd2fa9eb3848b7c9c2 Gitweb: https://git.kernel.org/tip/e121d64e16484d4a5eba94cd2fa9eb3848b7c9c2 Author: Byungchul Park <byungchul.p...@lge.com> AuthorDate: Wed, 25 Oct 2017 17:56:02 +0900 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Wed, 25 Oct 2017 12:19:02 +0200
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 <mi...@kernel.org> Signed-off-by: Byungchul Park <byungchul.p...@lge.com> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Thomas Gleixner <t...@linutronix.de> Cc: amir7...@gmail.com Cc: ax...@kernel.dk Cc: darrick.w...@oracle.com Cc: da...@fromorbit.com Cc: h...@infradead.org Cc: idryo...@gmail.com Cc: jo...@kernel.org Cc: johannes.b...@intel.com Cc: kernel-t...@lge.com Cc: linux-bl...@vger.kernel.org Cc: linux-fsde...@vger.kernel.org Cc: linux...@kvack.org Cc: linux-...@vger.kernel.org Cc: o...@redhat.com Cc: t...@kernel.org Link: http://lkml.kernel.org/r/1508921765-15396-7-git-send-email-byungchul.p...@lge.com Signed-off-by: Ingo Molnar <mi...@kernel.org> --- kernel/locking/lockdep.c | 4 ++++ lib/Kconfig.debug | 15 +++++++++++++++ 2 files changed, 19 insertions(+) diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index 160b5d6..db933d0 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 c1e720a..2b439a5 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
