From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0F7D4C11D20 for ; Thu, 20 Feb 2020 20:56:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D9D6820679 for ; Thu, 20 Feb 2020 20:56:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729196AbgBTU4j (ORCPT ); Thu, 20 Feb 2020 15:56:39 -0500 Received: from Galois.linutronix.de ([193.142.43.55]:44146 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729055AbgBTU4h (ORCPT ); Thu, 20 Feb 2020 15:56:37 -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 1j4srh-0007aD-R1; Thu, 20 Feb 2020 21:56:10 +0100 Received: from nanos.tec.linutronix.de (localhost [IPv6:::1]) by nanos.tec.linutronix.de (Postfix) with ESMTP id 4521010408B; Thu, 20 Feb 2020 21:56:04 +0100 (CET) Message-Id: <20200220204618.320890020@linutronix.de> User-Agent: quilt/0.65 Date: Thu, 20 Feb 2020 21:45:27 +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 10/20] trace/bpf: Use migrate disable in trace_call_bpf() References: <20200220204517.863202864@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 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: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org BPF does not require preemption disable. It only requires to stay on the same CPU while running a program. Reflect this by replacing preempt_disable/enable() with migrate_disable/enable() pairs. On a non-RT kernel this maps to preempt_disable/enable(). Signed-off-by: Thomas Gleixner --- kernel/trace/bpf_trace.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -83,7 +83,7 @@ unsigned int trace_call_bpf(struct trace if (in_nmi()) /* not supported yet */ return 1; - preempt_disable(); + migrate_disable(); if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) { /* @@ -115,7 +115,7 @@ unsigned int trace_call_bpf(struct trace out: __this_cpu_dec(bpf_prog_active); - preempt_enable(); + migrate_enable(); return ret; }