Messages in this thread Patch in this message | | | From | Waiman Long <> | Subject | [PATCH] locking/lockdep: Make MAX_STACK_TRACE_ENTRIES configurable | Date | Wed, 23 Aug 2017 14:18:58 -0400 |
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A "BUG: MAX_STACK_TRACE_ENTRIES too low!" error was hit when running a networking test on a 4.11 kernel. So even 512k of stack trace entries wasn't enough in this case.
Instead of hardcoding a larger MAX_STACK_TRACE_ENTRIES value, it is now made to be dependent on a new kernel configuration entry LOCKDEP_MAX_STACK_TRACE_ENTRIES so that kernel builders can configure a proper value depending on how the kernel is being used.
The default for this new config option is the same as the current value - 256k if LOCKDEP_SMALL and 512k otherwise.
Signed-off-by: Waiman Long <longman@redhat.com> --- kernel/locking/lockdep_internals.h | 6 ++++++ lib/Kconfig.debug | 12 ++++++++++++ 2 files changed, 18 insertions(+)
diff --git a/kernel/locking/lockdep_internals.h b/kernel/locking/lockdep_internals.h index 1da4669..0873e9b 100644 --- a/kernel/locking/lockdep_internals.h +++ b/kernel/locking/lockdep_internals.h @@ -77,6 +77,12 @@ enum { #define MAX_STACK_TRACE_ENTRIES 524288UL #endif +#ifdef CONFIG_LOCKDEP_MAX_STACK_TRACE_ENTRIES +#undef MAX_STACK_TRACE_ENTRIES +#define MAX_STACK_TRACE_ENTRIES \ + ((unsigned long)CONFIG_LOCKDEP_MAX_STACK_TRACE_ENTRIES) +#endif + #define MAX_LOCKDEP_CHAINS (1UL << MAX_LOCKDEP_CHAINS_BITS) #define MAX_LOCKDEP_CHAIN_HLOCKS (MAX_LOCKDEP_CHAINS*5) diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index ee9e534..0e8fc4e 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1230,6 +1230,18 @@ config WW_MUTEX_SELFTEST Say M if you want these self tests to build as a module. Say N if you are unsure. +# Allow 256k - 4M of lockdep stack trace entries +config LOCKDEP_MAX_STACK_TRACE_ENTRIES + int "Maximum number of lockdep stack trace entries" if LOCKDEP + range 262144 4194304 + default "262144" if LOCKDEP_SMALL + default "524288" if !LOCKDEP_SMALL + ---help--- + This specifies the maximum number of lockdep stack trace + entries that can be used by the locking correctness + validator. If this limit is exceeded, the validator will + be turned off. + endmenu # lock debugging config TRACE_IRQFLAGS -- 1.8.3.1
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