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| author | Paul E. McKenney <paulmck@kernel.org> | 2026-05-08 20:43:50 +0300 |
|---|---|---|
| committer | Uladzislau Rezki (Sony) <urezki@gmail.com> | 2026-05-24 10:39:47 +0300 |
| commit | 012c889690edc14d724a5880b4d0fe01c1fbb488 (patch) | |
| tree | 799e4a556df9f5d307d48c56db0011c3b3f59d7c /scripts/checkpatch.pl | |
| parent | e2f08cefcf483f56366e4daa292bb9ba113ec138 (diff) | |
| download | linux-012c889690edc14d724a5880b4d0fe01c1fbb488.tar.xz | |
checkpatch: Undeprecate rcu_read_lock_trace() and rcu_read_unlock_trace()
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.
Also, the rcu_read_lock_tasks_trace() and rcu_read_unlock_tasks_trace()
functions are intended for use only by BPF. Therefore, add them to
the list of functions that checkpatch complains about outside of BPF
(and of course, RCU).
Reported-by: Puranjay Mohan <puranjay@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: Joe Perches <joe@perches.com>
Cc: Dwaipayan Ray <dwaipayanray1@gmail.com>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Diffstat (limited to 'scripts/checkpatch.pl')
| -rwxr-xr-x | scripts/checkpatch.pl | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl index 0492d6afc9a1..cc5bbd70cb84 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 @@ -7596,12 +7594,15 @@ sub process { # Complain about RCU Tasks Trace used outside of BPF (and of course, RCU). our $rcu_trace_funcs = qr{(?x: + rcu_read_lock_tasks_trace | rcu_read_lock_trace | rcu_read_lock_trace_held | rcu_read_unlock_trace | + rcu_read_unlock_tasks_trace | call_rcu_tasks_trace | synchronize_rcu_tasks_trace | rcu_barrier_tasks_trace | + rcu_tasks_trace_expedite_current | rcu_request_urgent_qs_task )}; our $rcu_trace_paths = qr{(?x: |