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=-3.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 9401CC35646 for ; Fri, 21 Feb 2020 13:51:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6AB0920578 for ; Fri, 21 Feb 2020 13:51:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="gGDzdv1R" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729111AbgBUNvq (ORCPT ); Fri, 21 Feb 2020 08:51:46 -0500 Received: from bombadil.infradead.org ([198.137.202.133]:56324 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728646AbgBUNu1 (ORCPT ); Fri, 21 Feb 2020 08:50:27 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Content-Type:MIME-Version:References: Subject:Cc:To:From:Date:Message-Id:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:In-Reply-To; bh=xEZO8jQiUjD6Cw8Z5SrFWAbKXhwmoT9wPCbHC88J+aM=; b=gGDzdv1RSKknX1ahOL0kXPrLnb gWRG2EjxmL/P2gX/LfZvuwpaejSjtwb7i+wUQ0j5AcOhVS855Zq2f4xxPhx3dbzrDNSL1MnJFOB7P E+WHebeagImiiuv5bLdiZyxm1ItrLGlTzLCne74p6zwsDL9S+Z5Bbl6XWjNGk/EXZGljx/+u6eHVk 8dubqAz+tDc5b6Cxgtr+7H2qAPZfjobvXKTq7UcsYFXKiUNNdcrvQScdMtpc+NCn4JIuF/UW/GFwl 0sIWKN4dhtdKj5JzF678lXHPjm/UH9+VFMu0e+MdukeiAJkwJsx9/iIQV0j2DC9HLX6XJnN40cQpv 9sTsxtwA==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1j58gv-0000q9-Ku; Fri, 21 Feb 2020 13:50:05 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 796DB3077C4; Fri, 21 Feb 2020 14:48:08 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id E37AE29D740AE; Fri, 21 Feb 2020 14:50:00 +0100 (CET) Message-Id: <20200221134215.951340533@infradead.org> User-Agent: quilt/0.65 Date: Fri, 21 Feb 2020 14:34:31 +0100 From: Peter Zijlstra To: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, rostedt@goodmis.org Cc: peterz@infradead.org, mingo@kernel.org, joel@joelfernandes.org, gregkh@linuxfoundation.org, gustavo@embeddedor.com, tglx@linutronix.de, paulmck@kernel.org, josh@joshtriplett.org, mathieu.desnoyers@efficios.com, jiangshanlai@gmail.com, luto@kernel.org, tony.luck@intel.com, frederic@kernel.org, dan.carpenter@oracle.com, mhiramat@kernel.org Subject: [PATCH v4 15/27] tracing: Employ trace_rcu_{enter,exit}() References: <20200221133416.777099322@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Replace the opencoded (and incomplete) RCU manipulations with the new helpers to ensure a regular RCU context when calling into __ftrace_trace_stack(). Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Steven Rostedt (VMware) --- kernel/trace/trace.c | 19 +++---------------- 1 file changed, 3 insertions(+), 16 deletions(-) --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -2989,24 +2989,11 @@ void __trace_stack(struct trace_array *t int pc) { struct trace_buffer *buffer = tr->array_buffer.buffer; + int rcu_flags; - if (rcu_is_watching()) { - __ftrace_trace_stack(buffer, flags, skip, pc, NULL); - return; - } - - /* - * When an NMI triggers, RCU is enabled via rcu_nmi_enter(), - * but if the above rcu_is_watching() failed, then the NMI - * triggered someplace critical, and rcu_irq_enter() should - * not be called from NMI. - */ - if (unlikely(in_nmi())) - return; - - rcu_irq_enter_irqsave(); + rcu_flags = trace_rcu_enter(); __ftrace_trace_stack(buffer, flags, skip, pc, NULL); - rcu_irq_exit_irqsave(); + trace_rcu_exit(rcu_flags); } /**