[PATCH v4 4/7] locking/lockdep: Introduce CONFIG_BOOTPARAM_LOCKDEP_CROSSRELEASE_FULLSTACK
From: Byungchul Park <hidden>
Date: 2017-10-25 05:11:09
Also in:
linux-fsdevel, linux-mm, linux-xfs, lkml
Subsystem:
library code, locking primitives, the rest · Maintainers:
Andrew Morton, Peter Zijlstra, Ingo Molnar, Will Deacon, Boqun Feng, Linus Torvalds
The boot parameter, crossrelease_fullstack, was introduced to control whether to enable unwind in cross-release or not. Add a Kconfig doing the same thing. Suggested-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Byungchul Park <redacted> --- 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 @@ #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 4bef610..e4b54a5 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug@@ -1225,6 +1225,21 @@ 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
--
1.9.1