From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754312Ab3JNIZN (ORCPT ); Mon, 14 Oct 2013 04:25:13 -0400 Received: from LGEMRELSE1Q.lge.com ([156.147.1.111]:58638 "EHLO LGEMRELSE1Q.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753057Ab3JNIY3 (ORCPT ); Mon, 14 Oct 2013 04:24:29 -0400 X-AuditID: 9c93016f-b7c63ae00000696f-1a-525baa3c68f6 From: Namhyung Kim To: Steven Rostedt Cc: Frederic Weisbecker , Ingo Molnar , LKML , Namhyung Kim Subject: [PATCH 3/4] ftrace: Narrow down the protected area of graph_lock Date: Mon, 14 Oct 2013 17:24:25 +0900 Message-Id: <1381739066-7531-4-git-send-email-namhyung@kernel.org> X-Mailer: git-send-email 1.7.11.7 In-Reply-To: <1381739066-7531-1-git-send-email-namhyung@kernel.org> References: <1381739066-7531-1-git-send-email-namhyung@kernel.org> X-Brightmail-Tracker: AAAAAA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Namhyung Kim It seems that it doesn't need to hold graph_lock during preparation of the trace_parser. At least it makes the code a bit simpler IMHO. Signed-off-by: Namhyung Kim --- kernel/trace/ftrace.c | 22 +++++++++------------- 1 file changed, 9 insertions(+), 13 deletions(-) diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 0ff3449b4272..26a229ab0c19 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -3973,37 +3973,33 @@ ftrace_graph_write(struct file *file, const char __user *ubuf, size_t cnt, loff_t *ppos) { struct trace_parser parser; - ssize_t read, ret; + ssize_t read, ret = 0; struct ftrace_graph_data *fgd = file->private_data; if (!cnt) return 0; - mutex_lock(&graph_lock); - - if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX)) { - ret = -ENOMEM; - goto out_unlock; - } + if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX)) + return -ENOMEM; read = trace_get_user(&parser, ubuf, cnt, ppos); if (read >= 0 && trace_parser_loaded((&parser))) { parser.buffer[parser.idx] = 0; + mutex_lock(&graph_lock); + /* we allow only one expression at a time */ ret = ftrace_set_func(fgd->table, fgd->count, fgd->size, parser.buffer); - if (ret) - goto out_free; + + mutex_unlock(&graph_lock); } - ret = read; + if (!ret) + ret = read; -out_free: trace_parser_put(&parser); -out_unlock: - mutex_unlock(&graph_lock); return ret; } -- 1.7.11.7