From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753672Ab3H0UBx (ORCPT ); Tue, 27 Aug 2013 16:01:53 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:10717 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752605Ab3H0UBw (ORCPT ); Tue, 27 Aug 2013 16:01:52 -0400 X-Authority-Analysis: v=2.0 cv=DqnUCRD+ c=1 sm=0 a=Sro2XwOs0tJUSHxCKfOySw==:17 a=Drc5e87SC40A:10 a=xQxuxMh46K0A:10 a=5SG0PmZfjMsA:10 a=kj9zAlcOel0A:10 a=meVymXHHAAAA:8 a=KGjhK52YXX0A:10 a=RZDpadHLlpEA:10 a=QyXUC8HyAAAA:8 a=UF-aZLFQmoNNkeJJSAMA:9 a=CjuIK1q_8ugA:10 a=Sro2XwOs0tJUSHxCKfOySw==:117 X-Cloudmark-Score: 0 X-Authenticated-User: X-Originating-IP: 67.255.60.225 Date: Tue, 27 Aug 2013 16:01:50 -0400 From: Steven Rostedt To: Tom Zanussi Cc: masami.hiramatsu.pt@hitachi.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH v7 01/10] tracing: Add support for SOFT_DISABLE to syscall events Message-ID: <20130827160150.36f10869@gandalf.local.home> In-Reply-To: References: X-Mailer: Claws Mail 3.9.2 (GTK+ 2.24.20; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 27 Aug 2013 14:40:13 -0500 Tom Zanussi wrote: return; > - if (!test_bit(syscall_nr, tr->enabled_enter_syscalls)) > + > + /* Here we're inside the tp handler's rcu_read_lock (__DO_TRACE()) */ > + ftrace_file = rcu_dereference_raw(tr->enter_syscall_files[syscall_nr]); What's the reason for using rcu_dereference_raw() and not normal rcu_dereference? -- Steve > + if (!ftrace_file) > + return; > + > + if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags)) > return; >