Commit 1d7bf6b7 authored Feb 24, 2020 by Thomas Gleixner Committed by Alexei Starovoitov Feb 24, 2020

perf/bpf: Remove preempt disable around BPF invocation

The BPF invocation from the perf event overflow handler does not require to
disable preemption because this is called from NMI or at least hard
interrupt context which is already non-preemptible.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200224145643.151953573@linutronix.de

parent b0a81b94

kernel/events/core.c

+0 −2

Original line number	Diff line number	Diff line
		@@ -9206,7 +9206,6 @@ static void bpf_overflow_handler(struct perf_event *event,
		int ret = 0;

		ctx.regs = perf_arch_bpf_user_pt_regs(regs);
		preempt_disable();
		if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1))
		goto out;
		rcu_read_lock();
		@@ -9214,7 +9213,6 @@ static void bpf_overflow_handler(struct perf_event *event,
		rcu_read_unlock();
		out:
		__this_cpu_dec(bpf_prog_active);
		preempt_enable();
		if (!ret)
		return;