[PATCH tip/core/rcu 0/4] Add smp_call_function() debugging for v5.10

[Paul E. McKenney]

Hello!

This series adds debugging code for stalled smp_call_function() handlers:

1.	Add backtrace_idle parameter to force backtrace of idle CPUs.

2.	Add source and destination CPUs to __call_single_data.

3.	kernel/smp: Provide CSD lock timeout diagnostics.

4.	Make symbol 'csd_bug_count' static.

						Thanx, Paul

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

 Documentation/admin-guide/kernel-parameters.txt |    4 
 include/linux/smp.h                             |    3 
 include/linux/smp_types.h                       |    3 
 kernel/smp.c                                    |  136 +++++++++++++++++++++++-
 lib/Kconfig.debug                               |   11 +
 lib/nmi_backtrace.c                             |    6 -
 6 files changed, 161 insertions(+), 2 deletions(-)