Commit-ID: e121d64e16484d4a5eba94cd2fa9eb3848b7c9c2 Gitweb: https://git.kernel.org/tip/e121d64e16484d4a5eba94cd2fa9eb3848b7c9c2 Author: Byungchul Park <[email protected]> AuthorDate: Wed, 25 Oct 2017 17:56:02 +0900 Committer: Ingo Molnar <[email protected]> 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 <[email protected]> Signed-off-by: Byungchul Park <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> --- 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
