It turns out that there are BPF use cases that rely on nesting RCU Tasks Trace readers. These use cases are well-served by the old rcu_read_lock_trace() and rcu_read_unlock_trace() functions that maintain a nesting counter in the task_struct structure. But these use cases incur a performance penalty when using the shiny new rcu_read_lock_tasks_trace() and rcu_read_unlock_tasks_trace() functions, which nest in the same way that SRCU does.
This means that rcu_read_lock_trace() and rcu_read_unlock_trace() will be with us for some time. Therefore, remove the checkpatch.pl deprecation. Reported-by: Puranjay Mohan <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]> Cc: Andy Whitcroft <[email protected]> Cc: Joe Perches <[email protected]> Cc: Dwaipayan Ray <[email protected]> Cc: Lukas Bulwahn <[email protected]> --- scripts/checkpatch.pl | 2 -- 1 file changed, 2 deletions(-) diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl index 0492d6afc9a1fc..7a0aa139a2424a 100755 --- a/scripts/checkpatch.pl +++ b/scripts/checkpatch.pl @@ -865,8 +865,6 @@ our %deprecated_apis = ( "DEFINE_IDR" => "DEFINE_XARRAY", "idr_init" => "xa_init", "idr_init_base" => "xa_init_flags", - "rcu_read_lock_trace" => "rcu_read_lock_tasks_trace", - "rcu_read_unlock_trace" => "rcu_read_unlock_tasks_trace", ); #Create a search pattern for all these strings to speed up a loop below -- 2.40.1
