Subject: Re: [PATCH] arm64: ftrace: stop using kstop_machine to enable/disable
 tracing
To: Steven Rostedt <rostedt@goodmis.org>, Will Deacon <will.deacon@arm.com>
References: <1448697009-17211-1-git-send-email-huawei.libin@huawei.com>
 <20151202123654.GC4523@arm.com> <56600992.4040005@huawei.com>
 <20151203093821.GD7023@arm.com> <20151203100525.70cc40de@gandalf.local.home>
 <20151203150926.GG11337@arm.com> <20151203103139.35648cc2@gandalf.local.home>
CC: <mingo@redhat.com>, <catalin.marinas@arm.com>,
        <linux-arm-kernel@lists.infradead.org>, <linux-kernel@vger.kernel.org>,
        <guohanjun@huawei.com>, <dingtianhong@huawei.com>
From: libin <huawei.libin@huawei.com>
Message-ID: <5660E5B8.2050103@huawei.com>
Date: Fri, 4 Dec 2015 09:00:40 +0800
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101
 Thunderbird/38.1.0
MIME-Version: 1.0
In-Reply-To: <20151203103139.35648cc2@gandalf.local.home>
Content-Type: text/plain; charset="windows-1252"
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1400
Lines: 38


Thanks very much to Will and Steve for the wonderful comments, I will modify the
commit message, and remove the misleading comments about module text
disappearing case.

Thanks again,
Li Bin

on 2015/12/3 23:31, Steven Rostedt wrote:
> On Thu, 3 Dec 2015 15:09:26 +0000
> Will Deacon <will.deacon@arm.com> wrote:
>
>> Yeah, I think the comments on x86 and arm64 are out of date. They also
>> mention the freeing of __init sections -- is that still a concern?
> No we black list them, any section that we are not sure will be there
> when we expect it to has recordmcount.c nop out the calls to mcount and
> they are ignored. Remember the e1000e bug? This was the reproducer.
>
> Anyway, on my todo list is to allow init sections to be traced. To do
> so would mean that I need to add generic code that lets ftrace know to
> remove init sections at boot up. Right now (or at least the last time I
> checked, which was back in 2009), every arch had its own way of freeing
> init memory. If that has changed, or I can just place a hook where it
> happens (which is probably the easy part), I can allow init code to be
> traced too.
>
> -- Steve
>
>
> .
>


--
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/