diff mbox series

[V3,04/22] bpf/tracing: Remove redundant preempt_disable() in __bpf_trace_run()

Message ID 20200224145642.847220186@linutronix.de
State Accepted
Delegated to: BPF Maintainers
Headers show
Series bpf: Make BPF and PREEMPT_RT co-exist | expand

Commit Message

Thomas Gleixner Feb. 24, 2020, 2:01 p.m. UTC 
__bpf_trace_run() disables preemption around the BPF_PROG_RUN() invocation.

This is redundant because __bpf_trace_run() is invoked from a trace point
via __DO_TRACE() which already disables preemption _before_ invoking any of
the functions which are attached to a trace point.

Remove it and add a cant_sleep() check.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
V3: Add a cant_sleep() check. 
---
 kernel/trace/bpf_trace.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)
diff mbox series

Patch

--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -1516,10 +1516,9 @@  void bpf_put_raw_tracepoint(struct bpf_r
 static __always_inline
 void __bpf_trace_run(struct bpf_prog *prog, u64 *args)
 {
+	cant_sleep();
 	rcu_read_lock();
-	preempt_disable();
 	(void) BPF_PROG_RUN(prog, args);
-	preempt_enable();
 	rcu_read_unlock();
 }