From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755645AbaFKIHD (ORCPT ); Wed, 11 Jun 2014 04:07:03 -0400 Received: from lgeamrelo02.lge.com ([156.147.1.126]:52663 "EHLO lgeamrelo02.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754058AbaFKIG5 (ORCPT ); Wed, 11 Jun 2014 04:06:57 -0400 X-Original-SENDERIP: 10.177.220.181 X-Original-MAILFROM: namhyung@kernel.org From: Namhyung Kim To: Steven Rostedt Cc: LKML , Namhyung Kim , Namhyung Kim , Ingo Molnar Subject: [PATCH 2/2] tracing: Do not copy hash if O_TRUNC is set Date: Wed, 11 Jun 2014 17:06:54 +0900 Message-Id: <1402474014-28655-2-git-send-email-namhyung@kernel.org> X-Mailer: git-send-email 2.0.0 In-Reply-To: <1402474014-28655-1-git-send-email-namhyung@kernel.org> References: <1402474014-28655-1-git-send-email-namhyung@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When a filter file is open for writing and O_TRUNC is set, there's no need to copy and free the filter entries. Signed-off-by: Namhyung Kim --- kernel/trace/ftrace.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index ddfda763ded7..13885590a184 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -2759,7 +2759,13 @@ ftrace_regex_open(struct ftrace_ops *ops, int flag, hash = ops->filter_hash; if (file->f_mode & FMODE_WRITE) { - iter->hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, hash); + const int size_bits = FTRACE_HASH_DEFAULT_BITS; + + if (file->f_flags & O_TRUNC) + iter->hash = alloc_ftrace_hash(size_bits); + else + iter->hash = alloc_and_copy_ftrace_hash(size_bits, hash); + if (!iter->hash) { trace_parser_put(&iter->parser); kfree(iter); @@ -2768,10 +2774,6 @@ ftrace_regex_open(struct ftrace_ops *ops, int flag, } } - if ((file->f_mode & FMODE_WRITE) && - (file->f_flags & O_TRUNC)) - ftrace_filter_reset(iter->hash); - if (file->f_mode & FMODE_READ) { iter->pg = ftrace_pages_start; -- 2.0.0