From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934377AbZDJLJY (ORCPT ); Fri, 10 Apr 2009 07:09:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932349AbZDJLIx (ORCPT ); Fri, 10 Apr 2009 07:08:53 -0400 Received: from hera.kernel.org ([140.211.167.34]:45277 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1765549AbZDJLIv (ORCPT ); Fri, 10 Apr 2009 07:08:51 -0400 Date: Fri, 10 Apr 2009 11:07:01 GMT From: Lai Jiangshan To: linux-tip-commits@vger.kernel.org Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@redhat.com, fweisbec@gmail.com, srostedt@redhat.com, tglx@linutronix.de, laijs@cn.fujitsu.com, mingo@elte.hu Reply-To: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, fweisbec@gmail.com, srostedt@redhat.com, tglx@linutronix.de, laijs@cn.fujitsu.com, mingo@elte.hu In-Reply-To: <49D4666B.4010608@cn.fujitsu.com> References: <49D4666B.4010608@cn.fujitsu.com> Subject: [tip:tracing/core] tracing: allocate page when needed Message-ID: Git-Commit-ID: ddd538f3e6a1a4bec2f6942f83a753263e6577b4 X-Mailer: tip-git-log-daemon MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.0 (hera.kernel.org [127.0.0.1]); Fri, 10 Apr 2009 11:07:03 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: ddd538f3e6a1a4bec2f6942f83a753263e6577b4 Gitweb: http://git.kernel.org/tip/ddd538f3e6a1a4bec2f6942f83a753263e6577b4 Author: Lai Jiangshan AuthorDate: Thu, 2 Apr 2009 15:16:59 +0800 Committer: Ingo Molnar CommitDate: Fri, 10 Apr 2009 12:44:43 +0200 tracing: allocate page when needed 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 Cc: Frederic Weisbecker Cc: Steven Rostedt LKML-Reference: <49D4666B.4010608@cn.fujitsu.com> Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 16 ++++++++-------- 1 files changed, 8 insertions(+), 8 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 24b0168..8e189ff 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3277,19 +3277,13 @@ 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 @@ -3304,6 +3298,11 @@ 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; @@ -3342,7 +3341,8 @@ 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;