[PATCH v2 0/3] CSD-lock diagnostics enhancements

[Neeraj Upadhyay]

Hello!

This series adds following changes to the CSD-lock diagnostics (rebased on v6.10):

1.      locking/csd_lock: Print large numbers as negatives.

2.      locking/csd_lock: Provide an indication of ongoing CSD-lock stall.

3.      locking/csd-lock: Use backoff for repeated reports of same
        incident.

This is the second version of this patchset. Previous version can be found at [1]

Changes since v1:
- Rebase on v6.10
- Fix n_csd_lock_stuck atomic op in csd_lock_wait_toolong (Rik van Riel)
- Apply Rik van Riel's Reviewed-by.

Once reviewed/acked, current plan is to take this through RCU tree during v6.12 merge window,
as RCU commit "7d2ba698ad85 rcu: Summarize RCU CPU stall warnings during CSD-lock stalls" [2]
has dependency on these changes. If there are any concerns with taking these through RCU tree,
please raise those concerns.



[1] https://lore.kernel.org/lkml/20240713165642.GA215331@neeraj.linux/
[2] https://git.kernel.org/pub/scm/linux/kernel/git/neeraj.upadhyay/linux-rcu.git/commit/?h=rcustall.13.07.24a&id=7d2ba698ad85984656e9732d87b8e040a23baa55

Thanks
Neeraj

------------------------------------------------------------------------

 include/linux/smp.h |  6 ++++++
 kernel/smp.c        | 30 +++++++++++++++++++++++++-----
 2 files changed, 31 insertions(+), 5 deletions(-)