Re: [PATCH 2/3] Increase lockdep limits: MAX_LOCK_DEPTH

[Peter Zijlstra <a.p.zijlstra@chello.nl>]

On Tue, 2009-07-07 at 16:25 +0100, Joao Correia wrote:
> (Applies to current Linus tree, as of 2.6.31-rc2)
> 
> As a result of increasing MAX_STACK_TRACE_ENTRIES on the previous
> patch, another limit surfaced as being hit too soon.
> This patch increases MAX_LOCK_DEPTH, being hit by false positives, and
> turning off the locking correctness validator.
> 
> The new value is arbitrary, but I believe the old one was too. Given
> the amount of changes happening with regards to the usage of lockdep,
> the previous limit is just too low and keeping it that way would
> defeat the purpose of lockdep.
> 
> 
> Signed-off-by: Joao Correia <joaomiguelcorreia@gmail.com>

NAK, find the site that triggers this and fix it. holding more than 48
locks at any one time is silly.

> ---
>  include/linux/sched.h |    2 +-
>  1 files changes, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/include/linux/sched.h b/include/linux/sched.h
> index 0085d75..304231b 100644
> --- a/include/linux/sched.h
> +++ b/include/linux/sched.h
> @@ -1367,7 +1367,7 @@ struct task_struct {
>         int softirq_context;
>  #endif
>  #ifdef CONFIG_LOCKDEP
> -# define MAX_LOCK_DEPTH 48UL
> +# define MAX_LOCK_DEPTH 96UL
>         u64 curr_chain_key;
>         int lockdep_depth;
>         unsigned int lockdep_recursion;
> ---