From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755249Ab0ASHfk (ORCPT ); Tue, 19 Jan 2010 02:35:40 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755145Ab0ASHff (ORCPT ); Tue, 19 Jan 2010 02:35:35 -0500 Received: from cn.fujitsu.com ([222.73.24.84]:49895 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1754964Ab0ASHfc (ORCPT ); Tue, 19 Jan 2010 02:35:32 -0500 Message-ID: <4B556070.6000204@cn.fujitsu.com> Date: Tue, 19 Jan 2010 15:34:08 +0800 From: Lai Jiangshan User-Agent: Thunderbird 2.0.0.6 (Windows/20070728) MIME-Version: 1.0 To: Steven Rostedt , linux-kernel@vger.kernel.org, Ingo Molnar , Andrew Morton , Frederic Weisbecker Subject: [PATCH 3/6] tracing: tracing_stats_read() uses simple buffer instead of trace_seq 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 It seems that struct trace_seq is too heavy for tracing_stats_read(). we use simple buffer instead of struct trace_seq. Signed-off-by: Lai Jiangshan --- diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 27fecf8..aa1cd92 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3807,27 +3807,22 @@ tracing_stats_read(struct file *filp, char __user *ubuf, { unsigned long cpu = (unsigned long)filp->private_data; struct trace_array *tr = &global_trace; - struct trace_seq *s; unsigned long cnt; - s = kmalloc(sizeof(*s), GFP_KERNEL); - if (!s) - return -ENOMEM; - - trace_seq_init(s); + unsigned char buf[128]; + int len = 0; cnt = ring_buffer_entries_cpu(tr->buffer, cpu); - trace_seq_printf(s, "entries: %ld\n", cnt); + len += sprintf(buf + len, "entries: %ld\n", cnt); cnt = ring_buffer_overrun_cpu(tr->buffer, cpu); - trace_seq_printf(s, "overrun: %ld\n", cnt); + len += sprintf(buf + len, "overrun: %ld\n", cnt); cnt = ring_buffer_commit_overrun_cpu(tr->buffer, cpu); - trace_seq_printf(s, "commit overrun: %ld\n", cnt); - - count = simple_read_from_buffer(ubuf, count, ppos, s->buffer, s->len); + len += sprintf(buf + len, "commit overrun: %ld\n", cnt); - kfree(s); + BUG_ON(len >= sizeof(buf)); /* should not happen, 128 is enough. */ + count = simple_read_from_buffer(ubuf, count, ppos, buf, len); return count; }