Re: [PATCH 0/4] Lockdep: Reduce stack trace memory usage

[Peter Zijlstra]

On Mon, Jul 22, 2019 at 11:24:39AM -0700, Bart Van Assche wrote:
> Hi Peter,
> 
> An unfortunate side effect of commit 669de8bda87b ("kernel/workqueue: Use
> dynamic lockdep keys for workqueues") is that all stack traces associated
> with the lockdep key are leaked when a workqueue is destroyed. Fix this by
> storing each unique stack trace once. Please consider this patch series
> for Linux kernel v5.4.
> 
> Thanks,
> 
> Bart.
> 
> Bart Van Assche (4):
>   locking/lockdep: Make it clear that what lock_class::key points at is
>     not modified
>   stacktrace: Constify 'entries' arguments
>   locking/lockdep: Reduce space occupied by stack traces
>   locking/lockdep: Report more stack trace statistics
> 
>  include/linux/lockdep.h            |  11 +-
>  include/linux/stacktrace.h         |   4 +-
>  kernel/locking/lockdep.c           | 159 ++++++++++++++++++++++-------
>  kernel/locking/lockdep_internals.h |   9 +-
>  kernel/locking/lockdep_proc.c      |   8 +-
>  kernel/stacktrace.c                |   4 +-
>  6 files changed, 143 insertions(+), 52 deletions(-)

Thanks a lot for doing this Bart, excellent stuff!