Message-ID: <4B5D3D37.4090107@cn.fujitsu.com>
Date: Mon, 25 Jan 2010 14:41:59 +0800
From: Lai Jiangshan <laijs@cn.fujitsu.com>
User-Agent: Thunderbird 2.0.0.6 (Windows/20070728)
MIME-Version: 1.0
To: Frederic Weisbecker <fweisbec@gmail.com>
CC: Ingo Molnar <mingo@elte.hu>, LKML <linux-kernel@vger.kernel.org>,
       Steven Rostedt <rostedt@goodmis.org>, Li Zefan <lizf@cn.fujitsu.com>
Subject: Re: [RFC PATCH 06/10] ftrace: Release the function hlist if we don't
 need it anymore
References: <1264122982-1553-1-git-send-regression-fweisbec@gmail.com> <1264122982-1553-7-git-send-regression-fweisbec@gmail.com>
In-Reply-To: <1264122982-1553-7-git-send-regression-fweisbec@gmail.com>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1476
Lines: 41

Frederic Weisbecker wrote:
> After we disable the function profiler, the function hashlist
> stays in memory. This is wasteful as nobody needs it anymore,
> until the next use if any.
> 
> Release it when we disable the function profiler instead of
> resetting it in the next use.
> 
> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
> Cc: Steven Rostedt <rostedt@goodmis.org>
> Cc: Li Zefan <lizf@cn.fujitsu.com>
> Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
> ---
>  kernel/trace/ftrace.c          |    1 +
>  kernel/trace/functions_hlist.c |   61 +++++++++++++++++-----------------------
>  kernel/trace/functions_hlist.h |    1 +
>  3 files changed, 28 insertions(+), 35 deletions(-)
> 
> diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
> index dfd8f7c..0ded01c 100644
> --- a/kernel/trace/ftrace.c
> +++ b/kernel/trace/ftrace.c
> @@ -509,6 +509,7 @@ ftrace_profile_write(struct file *filp, const char __user *ubuf,

>			/*
>			 * unregister_ftrace_profiler calls stop_machine
>			 * so this acts like an synchronize_sched.
>			 */
>  			unregister_ftrace_profiler();

unluckily, when !CONFIG_DYNAMIC_FTRACE, it does not call stop_machine()
nor synchronize_sched(), bug here?

> +			function_hlist_release();


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/