Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751590AbdISRn2 (ORCPT ); Tue, 19 Sep 2017 13:43:28 -0400 Received: from hqemgate14.nvidia.com ([216.228.121.143]:12251 "EHLO hqemgate14.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751411AbdISRn1 (ORCPT ); Tue, 19 Sep 2017 13:43:27 -0400 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Tue, 19 Sep 2017 10:43:10 -0700 Subject: Re: [PATCH] tracing: erase irqsoff trace with empty write To: Steven Rostedt CC: , References: <1505153795-12484-1-git-send-email-byan@nvidia.com> <20170918103840.1d283502@gandalf.local.home> X-Nvconfidentiality: public From: Bo Yan Message-ID: Date: Tue, 19 Sep 2017 10:41:34 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.3.0 MIME-Version: 1.0 In-Reply-To: <20170918103840.1d283502@gandalf.local.home> X-Originating-IP: [172.17.185.27] X-ClientProxiedBy: HQMAIL102.nvidia.com (172.18.146.10) To HQMAIL108.nvidia.com (172.18.146.13) Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1976 Lines: 63 Steven, Thanks for review. I have posted the following update https://lkml.org/lkml/2017/9/18/715 Bo On 09/18/2017 07:38 AM, Steven Rostedt wrote: > On Mon, 11 Sep 2017 11:16:35 -0700 > Bo Yan wrote: > >> One convenient way to erase trace is "echo > trace". However, this >> is currently broken if the current tracer is irqsoff tracer. This >> is because irqsoff tracer use max_buffer as the default trace >> buffer. >> >> Set the max_buffer as the one to be cleared when it's the trace >> buffer currently in use. > > Hi Bo, > > I have no problems with the logic of the patch. But just one nit. The > tr->trace_buffer has been called "trace_buf" elsewhere in the file. Can > you resend with using the variable name "trace_buf" instead of "tr_buf" > just to keep it consistent in the file. It's also been called 'buf' but > trace_buf would probably be more appropriate. > > Thanks! > > -- Steve > >> >> Signed-off-by: Bo Yan >> --- >> kernel/trace/trace.c | 10 ++++++++-- >> 1 file changed, 8 insertions(+), 2 deletions(-) >> >> diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c >> index 5360b7aec57a..1f91bdd9365b 100644 >> --- a/kernel/trace/trace.c >> +++ b/kernel/trace/trace.c >> @@ -4020,11 +4020,17 @@ static int tracing_open(struct inode *inode, struct file *file) >> /* If this file was open for write, then erase contents */ >> if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { >> int cpu = tracing_get_cpu(inode); >> + struct trace_buffer *tr_buf = &tr->trace_buffer; >> + >> +#ifdef CONFIG_TRACER_MAX_TRACE >> + if (tr->current_trace->print_max) >> + tr_buf = &tr->max_buffer; >> +#endif >> >> if (cpu == RING_BUFFER_ALL_CPUS) >> - tracing_reset_online_cpus(&tr->trace_buffer); >> + tracing_reset_online_cpus(tr_buf); >> else >> - tracing_reset(&tr->trace_buffer, cpu); >> + tracing_reset(tr_buf, cpu); >> } >> >> if (file->f_mode & FMODE_READ) { >