The call_rcu_tasks_rude() and rcu_barrier_tasks_rude() APIs are no longer.
This commit therefore removes them from the rcu-updaters.sh script.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Neeraj Upadhyay <neeraj.upadhyay@kernel.org>

This commit adds a tools/rcu/rcu-updaters.sh script that uses bpftrace
to print a histogram of the RCU update-side primitives invoked during
the specified time interval, or until manually terminated if no interval
is specified.

Sample output on an idle laptop:

@counts[poll_state_synchronize_rcu]: 6
@counts[synchronize_srcu]: 13
@counts[call_rcu_tasks_trace]: 25
@counts[synchronize_rcu]: 54
@counts[kvfree_call_rcu]: 428
@counts[call_rcu]: 2134

Note that when run on a kernel missing one or more of the symbols, this
script will issue a diagnostic for each that is not found, but continue
normally for the rest of the functions.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

This commit converts extract-stall.sh script's header comment to a
usage() function, and adds an argument check.  While in the area, make
this script be executable.

[ paulmck: Strength argument check, remove extraneous comment. ]

Signed-off-by: Bhaskar Chowdhury <unixbhaskar@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>

This commit adds a script that extracts RCU CPU stall warnings
from console output.  The user can optionally specify the number of
lines preceding the stall to output, and also the number of lines of
stall-warning text.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

This commit adds an rcu-cbs.py drgn script that computes the number of
RCU callbacks waiting to be invoked.  This information can be helpful
when managing systems that are short of memory and that have software
components that make heavy use of RCU, for example, by opening and
closing files in tight loops.  (But please note that there are almost
always better ways to get your job done than by opening and closing
files in tight loops.)

Reported-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>