From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759549AbZDBHSu (ORCPT ); Thu, 2 Apr 2009 03:18:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752909AbZDBHSk (ORCPT ); Thu, 2 Apr 2009 03:18:40 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:56259 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1750897AbZDBHSj (ORCPT ); Thu, 2 Apr 2009 03:18:39 -0400 Message-ID: <49D4666B.4010608@cn.fujitsu.com> Date: Thu, 02 Apr 2009 15:16:59 +0800 From: Lai Jiangshan User-Agent: Thunderbird 2.0.0.6 (Windows/20070728) MIME-Version: 1.0 To: Steven Rostedt CC: Ingo Molnar , Frederic Weisbecker , LKML Subject: [PATCH 2/4] tracing: allocate page when need Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Impact: Cleanup Sometimes, we open trace_pipe_raw, but we don't read(2) it, we just splice(2) it, thus, the page is not used. Signed-off-by: Lai Jiangshan --- diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 7283b99..20e9f33 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3257,19 +3257,13 @@ static int tracing_buffers_open(struct inode *inode, struct file *filp) info->tr = &global_trace; info->cpu = cpu; - info->spare = ring_buffer_alloc_read_page(info->tr->buffer); + info->spare = NULL; /* Force reading ring buffer for first read */ info->read = (unsigned int)-1; - if (!info->spare) - goto out; filp->private_data = info; return nonseekable_open(inode, filp); - - out: - kfree(info); - return -ENOMEM; } static ssize_t @@ -3284,6 +3278,11 @@ tracing_buffers_read(struct file *filp, char __user *ubuf, if (!count) return 0; + if (!info->spare) + info->spare = ring_buffer_alloc_read_page(info->tr->buffer); + if (!info->spare) + return -ENOMEM; + /* Do we have previous read data to read? */ if (info->read < PAGE_SIZE) goto read; @@ -3322,7 +3321,8 @@ static int tracing_buffers_release(struct inode *inode, struct file *file) { struct ftrace_buffer_info *info = file->private_data; - ring_buffer_free_read_page(info->tr->buffer, info->spare); + if (info->spare) + ring_buffer_free_read_page(info->tr->buffer, info->spare); kfree(info); return 0;