0628f6e9f85c469ceccb5c0 parent 0ddea0ead2ced99eaaaddff2beb755381e5c89f8 author Paul E. McKenney 1283894589 -0700 committer Paul E. McKenney 1285258613 -0700 rcu: Add tracing data to support queueing models The current tracing data is not sufficient to deduce the average time that a callback spends waiting for a grace period to end. Add three per-CPU counters recording the number of callbacks invoked (ci), the number of callbacks orphaned (co), and the number of callbacks adopted (ca). Given the existing callback queue length (ql), the average wait time in absence of CPU hotplug operations is ql/ci. The units of wait time will be in terms of the duration over which ci was measured. In the presence of CPU hotplug operations, there is room for argument, but ql/(ci-co+ca) won't steer you too far wrong. Also fixes a typo called out by Lucas De Marchi . Signed-off-by: Paul E. McKenney –~ać™