From patchwork Thu Feb 20 20:45:21 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Gleixner X-Patchwork-Id: 1241658 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (no SPF record) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=linutronix.de Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 48Nn3W1tc5z9sRG for ; Fri, 21 Feb 2020 07:57:43 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729421AbgBTU5l (ORCPT ); Thu, 20 Feb 2020 15:57:41 -0500 Received: from Galois.linutronix.de ([193.142.43.55]:44164 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729211AbgBTU4k (ORCPT ); Thu, 20 Feb 2020 15:56:40 -0500 Received: from p5de0bf0b.dip0.t-ipconnect.de ([93.224.191.11] helo=nanos.tec.linutronix.de) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1j4srb-0007TA-D5; Thu, 20 Feb 2020 21:56:03 +0100 Received: from nanos.tec.linutronix.de (localhost [IPv6:::1]) by nanos.tec.linutronix.de (Postfix) with ESMTP id D3B06104085; Thu, 20 Feb 2020 21:56:02 +0100 (CET) Message-Id: <20200220204617.728659044@linutronix.de> User-Agent: quilt/0.65 Date: Thu, 20 Feb 2020 21:45:21 +0100 From: Thomas Gleixner To: LKML Cc: David Miller , bpf@vger.kernel.org, netdev@vger.kernel.org, Alexei Starovoitov , Daniel Borkmann , Sebastian Sewior , Peter Zijlstra , Clark Williams , Steven Rostedt , Juri Lelli , Ingo Molnar , Mathieu Desnoyers , Vinicius Costa Gomes , Jakub Kicinski Subject: [patch V2 04/20] perf/bpf: Remove preempt disable around BPF invocation References: <20200220204517.863202864@linutronix.de> MIME-Version: 1.0 X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1, SHORTCIRCUIT=-0.0001 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org 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 --- kernel/events/core.c | 2 -- 1 file changed, 2 deletions(-) --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -9206,7 +9206,6 @@ static void bpf_overflow_handler(struct 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 rcu_read_unlock(); out: __this_cpu_dec(bpf_prog_active); - preempt_enable(); if (!ret) return;