Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751029AbdIKSS3 (ORCPT ); Mon, 11 Sep 2017 14:18:29 -0400 Received: from hqemgate14.nvidia.com ([216.228.121.143]:4576 "EHLO hqemgate14.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750945AbdIKSS2 (ORCPT ); Mon, 11 Sep 2017 14:18:28 -0400 X-PGP-Universal: processed; by hqpgpgate102.nvidia.com on Mon, 11 Sep 2017 11:18:07 -0700 From: Bo Yan To: , , CC: Bo Yan Subject: [PATCH] tracing: erase irqsoff trace with empty write Date: Mon, 11 Sep 2017 11:16:35 -0700 Message-ID: <1505153795-12484-1-git-send-email-byan@nvidia.com> X-Mailer: git-send-email 2.7.4 X-NVConfidentiality: public MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1252 Lines: 39 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. 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) { -- 2.7.4