From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753216Ab3CKHO2 (ORCPT ); Mon, 11 Mar 2013 03:14:28 -0400 Received: from szxga02-in.huawei.com ([119.145.14.65]:26504 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753104Ab3CKHOX (ORCPT ); Mon, 11 Mar 2013 03:14:23 -0400 Message-ID: <513D8441.7050807@huawei.com> Date: Mon, 11 Mar 2013 15:14:09 +0800 From: "zhangwei(Jovi)" User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:17.0) Gecko/17.0 Thunderbird/17.0 MIME-Version: 1.0 To: "linux-kernel@vger.kernel.org" , Steven Rostedt , Frederic Weisbecker , Ingo Molnar Subject: [PATCH 09/13] tracing: use trace_seq_init to initize seq field in trace_iterator Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.66.58.241] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org the size of seq field in trace_iterator is more than PAGE_SIZE, so seq memset is expensive, try to use cheap seq init method: trace_seq_init Signed-off-by: zhangwei(Jovi) --- kernel/trace/trace.c | 10 ++++++---- kernel/trace/trace_kdb.c | 5 +++-- 2 files changed, 9 insertions(+), 6 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 4cec7b8..c7cc915 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3551,9 +3551,10 @@ waitagain: cnt = PAGE_SIZE - 1; /* reset all but tr, trace, and overruns */ - memset(&iter->seq, 0, + trace_seq_init(&iter->seq); + memset(&iter->ent, 0, sizeof(struct trace_iterator) - - offsetof(struct trace_iterator, seq)); + offsetof(struct trace_iterator, ent)); iter->pos = -1; trace_event_read_lock(); @@ -5167,9 +5168,10 @@ __ftrace_dump(bool disable_tracing, enum ftrace_dump_mode oops_dump_mode) cnt++; /* reset all but tr, trace, and overruns */ - memset(&iter.seq, 0, + trace_seq_init(&iter.seq); + memset(&iter.ent, 0, sizeof(struct trace_iterator) - - offsetof(struct trace_iterator, seq)); + offsetof(struct trace_iterator, ent)); iter.iter_flags |= TRACE_FILE_LAT_FMT; iter.pos = -1; diff --git a/kernel/trace/trace_kdb.c b/kernel/trace/trace_kdb.c index 6489b2e..84f1584 100644 --- a/kernel/trace/trace_kdb.c +++ b/kernel/trace/trace_kdb.c @@ -37,9 +37,10 @@ static void ftrace_dump_buf(int skip_lines, long cpu_file) kdb_printf("Dumping ftrace buffer:\n"); /* reset all but tr, trace, and overruns */ - memset(&iter.seq, 0, + trace_seq_init(&iter.seq); + memset(&iter.ent, 0, sizeof(struct trace_iterator) - - offsetof(struct trace_iterator, seq)); + offsetof(struct trace_iterator, ent)); iter.iter_flags |= TRACE_FILE_LAT_FMT; iter.pos = -1; -- 1.7.9.7